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CDC Health Information for International Travelers: Special Needs Travelers

CDC Health Information for International Travelers: Special Needs Travelers

INTERNATIONAL TRAVELERS WITH DISABILITIES
THE IMMUNOCOMPROMISED TRAVELER
PREGNANCY AND TRAVEL
IMMUNIZATIONS
BREASTFEEDING AND TRAVEL
VACCINE RECOMMENDATIONS FOR INFANTS AND CHILDREN
INTERNATIONAL ADOPTIONS

Editor's note: The information below was posted on the Center for Disease Control and Prevention web site (wwwn.cdc.gov/travel) as of June 2007 and has been condensed by the editors for publication in book format. Readers should consult wwwn.cdc.gov/travel for additional information, updates, or revisions.

INTERNATIONAL TRAVELERS WITH DISABILITIES

The medical preparation of a traveler with a stable, ongoing disability does not differ from that of any other traveler. The keys to safe, accessible travel are that each anticipated international itinerary must be assessed on an individual basis, in consultation with specialized travel agencies or tour operators; that travel health providers be consulted for additional recommendations; and that print and Internet resources be utilized as well.

Air Travel

By law, U.S. air carriers must comply with highly detailed regulations which affect people with disabilities. These do not cover foreign carriers serving the United States. However, all U.S. and non-U.S. carriers are required to file annual reports of disability-related complaints with the U.S. Department of Transportation (DOT). The DOT maintains a toll-free hotline (1-800-778-4838, available 7 a.m. to 11 p.m. Eastern Standard Time) to provide real-time assistance in facilitating compliance with DOT rules and to suggest customer-service solutions to the airlines. Carriers may not refuse transportation on the basis of disability. Airlines may not require advance notice that a person with a disability is traveling; however, they may require up to 48 hours advance notice for certain accommodations that require preparation time.

International Air Transport Association (IATA) member airlines voluntarily adhere to codes of practice that are very similar to U.S. legislation based on guidance from the International Civil Aviation Organization. However, smaller airlines overseas may not be IATA members. Airlines are obliged to accept a declaration by a passenger that he/she is self-reliant. Medical certificates can be required only in specific situations (for example, if a person intends to travel with a possible communicable disease, will require a stretcher or oxygen, or if unusual behavior is anticipated that may affect the operation of the flight).

When a disabled person requests assistance, the airline is obliged to provide access to the aircraft door (preferably by a level entry bridge), an aisle wheelchair, and a seat with removable armrests. Aircraft with fewer than 30 seats are generally exempt. Airline personnel are not required to transfer passengers from wheelchair to wheelchair, wheel-chair to aircraft seat, or wheelchair to lavatory seat. Disabled passengers who cannot transfer themselves should travel with a companion or attendant, but carriers may not without reason require a person with a disability to travel with an attendant.

Only wide-body aircraft with two aisles are required to have fully accessible lavatories, although any aircraft with more than 60 seats must have an on-board wheelchair, and personnel must assist with movement of the wheelchair from the seat to the area outside the lavatory. Wet-acid batteries in electric wheelchairs may require special separate stowage. Airline personnel are not obliged to assist with feeding, visiting the lavatory, or dispensing medication to travelers.

Internationally standardized codes for classifying disabled passengers and their needs are available in all computerized reservations systems. Disabled passengers should use travel agents experienced in the use of the disability coding; it is critical that appropriate codes and inter-airline messages are sequentially entered for all flights. The delivering carrier is always responsible for a disabled passenger until a subsequent carrier physically accepts responsibility for that passenger.

Service Animals

Service animals are not exempt from compliance with quarantine regulations and so may not be allowed to travel to all international destinations. They are also subject to US Animal Import Regulations on return.

Cruise Ships

U.S. companies or entities conducting programs or tours on cruise ships have obligations regarding access for travelers with disabilities, even if the ship itself is of foreign registry. However, all travelers with disabilities should check with individual cruise lines regarding availability of requested or needed items prior to booking. Cruises are available that cater to travelers with special needs, such as dialysis patients.

Useful Links

MossRehab ResourceNet. http://www.mossresourcenet.org/travel.htm

New Horizons Information for the Air Traveler with a Disability. Full text at http://airconsumer.ost.dot.gov/publications/horizons.htm

American Council of the Blind. http://www.acb.org/resources/travel.html. Lists cruises, books, useful telephone numbers, and links to products for purchase

Access-Able. http://www.access-able.com. Resource for mature and travelers with special needs

Non-discrimination on the Basis of Disability in Air Travel. 14 CFR Part 382 (Federal Rules) http://airconsumer.ost.dot.gov/rules/rules.htm

Security Checkpoints for Travelers with Disabilities. http://www.tsa.gov/travelers/airtravel/specialneeds

Society for Accessible Travel and Hospitality. http://www.sath.org

THE IMMUNOCOMPROMISED TRAVELER

Risk Assessment in the Immunocompromised Traveler

The main risk for the immunocompromised traveler is a complication or exacerbation of the underlying disease. In addition, endemic infectious diseases that may be acquired at the destination(s) may cause disease of increased severity in the traveler. Each proposed preventive intervention must be examined from two perspectives: 1) safety in the context of the underlying illness and the medication(s) being taken; and 2) the possibility of decreased effectiveness of the intervention. The medical provider should ensure that the traveler under-stands the risks involved of the proposed itinerary, based on his/her medical needs and the traveler's individual tolerance for the risks of the proposed interventions and of the travel itself.

Specific Immunocompromising Conditions

The degree to which a person is immunocompromised should be determined by a health-care provider. For practical purposes, immunocompromised travelers can be categorized into one of four groups, each with a general approach.

Severe Immunocompromise (Non-HIV)

Persons considered as having severe immunosuppression include those who have active leukemia or lymphoma, generalized malignancy, aplastic anemia, graft versus host disease or congenital immunodeficiency, or persons who have received current or recent radiation therapy, solid organ transplant, or bone marrow transplant within 2 years of transplantation; or persons whose transplants are of longer duration but who are still taking immunosuppressive drugs. For solid organ transplants, much higher risk of infection occurs within the first year of transplant, so high-risk travel might be postponed until after that time.

Medications that cause severe immunosuppression include high-dose corticosteroids, alkylating agents (e.g., cyclophosphamide), antimetabolites (e.g., azathioprine, 6-mercaptopurine), transplant-related immunosuppressive drugs (e.g., cyclosporine, tacrolimus, sirolimus, and myco-phenolate mofetil), mitoxantrone (used in multiple sclerosis), and most cancer chemotherapeutic agents (excluding tamoxifen). Methotrexate, including low-dose weekly regimens, is classified as severely immunosuppressive, as evidenced by increased rates of opportunistic infections and blunting of responses to killed vaccines.

The immunosuppressive effects of steroid treatment vary, but the majority of clinicians consider a dose equivalent to either >2 mg/kg of body weight or 20 mg/day of prednisone or equivalent for persons who weigh >10 kg when administered for 2 weeks as sufficiently immunosuppressive to raise concern about the safety of vaccination with live-virus vaccines. Corticosteroids used in greater than physiologic doses also can reduce the immune response to vaccines. Vaccination providers should wait at least 1 month after discontinuation of high dose systemically absorbed corticosteroid therapy administered for more than 2 weeks before administering a live-virus vaccine. Tumor necrosis factor (TNF)-blocking agents such as etanercept, adali-mumab, and infliiximab are known to activate latent myco-bacterial infection as well as to increase overall susceptibility to other serious infections. Although the benefits of live viral and bacterial vaccines in persons receiving TNF-blocking agents need to be carefully weighed against potential risk, most practicing clinicians would be reluctant to use such vaccines in this situation. The safety of using live vaccines is unknown for persons taking TNF-alpha blocking agents or interleukin-1 receptor antagonist (IL-lra).

Severe Immunocompromise Due To Symptomatic HIV/AIDS

Knowledge of a current CD4 lymphocyte count is necessary before consultation with the HIV-infected traveler. HIV-infected persons with CD4 counts lower than 200, history of an AIDS-defining illness, or clinical manifestations of symptomatic HIV are considered to have severe immuno-suppression. In newly diagnosed, treatment-naïve patients with CD4 counts lower than 200, travel should be delayed pending reconstitution of CD4 counts with antiretroviral therapy. This delay will minimize risk of infection and avoid immune-reconstitution illness during the travel.

Asymptomatic HIV Infection

Asymptomatic HIV-infected persons with CD4 counts from 200 to 500 are considered to have limited immune deficits. CD4 counts increased by antiretroviral drugs, rather than nadir counts, should be used in categorizing HIV-infected persons. The exact time at which reconstituted lymphocytes are fully functional is not well defined. To achieve maximal vaccine response with minimal risk, if possible, many clinicians advise a delay of 3 months post-reconstitution before immunizations are administered.

Chronic Diseases with Limited Immune Deficits

These chronic diseases include asplenia, chronic renal disease, chronic hepatic disease (cirrhosis and alcoholism), diabetes, and nutritional deficiencies. Patients taking rib-avirin and interferon for hepatitis C infection are at risk for neutropenia, although no clinically apparent increase in opportunistic infections has been described. No information on possible decreased vaccine efficacy or increased adverse events with live viral antigens is available for this group.

Persons Considered To Have No Immunologic Compromise

For the purpose of pre-travel preparation, travelers with the following conditions are not considered to be immuno-compromised and should be prepared as any other traveler, although the nature of the previous or underlying disease needs to be kept in mind:

  • Corticosteroid therapy under the following circumstances: short or long term daily or alternate day therapy with 20 mg or less of prednisone or equivalent; long-term, alternate day treatment with short-acting preparations; maintenance physiologic doses (replacement therapy); steroid inhalers; topical steroids (skin, ears, or eyes); intra-articular, bursal, or tendon injection of steroids; or if longer than 1 month has passed since high-dose steroids (greater than 20 mg per day of prednisone or equivalent for longer than 2 weeks) have been used. Some experts will wait 2 weeks prior to the administration of measles vaccine following short-term (less than 2 weeks) of therapy with daily or alternate day dosing of greater than 20 mg of prednisone or equivalent.
  • HIV patients with >500 CD4 lymphocytes.
  • Longer than 3 months since chemotherapy for leukemia/lymphoma or cancer, and the malignancy is in remission. Although some clinicians suggest waiting only 1 month since a last dose of immunosuppressive medications (including TNF-blockers) that are not being used for the chemotherapy of cancer, data are inconclusive. This recommendation may primarily refer to corticosteroids, but it remains unknown exactly how long is safest.
  • Bone marrow transplant, if longer than 2 years post-transplant, not on immunosuppressive drugs and without graft versus host disease.
  • Definitive data do not exist with respect to autoimmune diseases in the absence of any overlay of immuno-suppressive drugs (e.g., systemic lupus erythematosus, inflammatory bowel disease, rheumatoid arthritis, or multiple sclerosis). The ACIP's advice for the normal use of all live-virus as well as killed vaccines in multiple sclerosis (MS) patients who are not undergoing a current exacerbation of disease is reinforced by the National MS Society (www.nationalmssociety.org/Sourcebook-vaccinations.asp), a source well respected by MS patients and their physicians. In the past, many practicing neurologists have strongly advised their MS patients against the use of live-virus vaccines at any time. If possible, MS patients should not receive any vaccine for 6 weeks after the onset of a disease exacerbation. Immunomodulatory agents commonly used in MS patients, such as interferons and glatiramer acetate, are not thought to affect vaccine response or safety, but definitive data are lacking.

Vaccine Administration

Travelers with symptomatic HIV or severe non-HIV immunocompromise 1) cannot be given live-virus or live bacterial vaccines; 2) may require additional vaccines when compared with the healthy traveler; and 3) may receive decreased protection from some or all vaccines administered. Use of vaccines for different categories of immunocompromised adults is shown in Table 9-1 (10,11). Overall considerations for travel-related vaccines, such as destination and risk behavior, are the same as for other travelers, although the consequences of not administering an indicated vaccine may be more severe. A high risk for acquiring infections should prompt discussion of trip deferral or consideration of an alternate itinerary.

Vaccine Considerations for Certain Hosts

Transient increases in HIV viral load, which return quickly to baseline, have been observed after administration of several different vaccines to HIV-infected persons. The clinical significance of these increases is not known, but they do not preclude the use of any vaccine. Patients receiving any vaccines while receiving immunosuppressive therapy or in the 2 weeks before starting therapy because of imminent travel are not considered to have received valid vaccine doses. At least 3 months after therapy is discontinued, these patients should be revaccinated with all vaccines that are still indicated at that time.

Vaccine doses received by HIV-infected individuals while CD4 counts are less than 200 should be ignored, and the individual should be revaccinated at least 3 months after immune reconstitution with antiretroviral therapy.

Complete revaccination with standard childhood vaccines should begin 12 months after bone marrow transplantation (BMT). However, MMR vaccine should be administered at 24 months after BMT if the recipient is presumed to be immunocompetent. Influenza vaccine should be administered at 6 months after BMT and annually thereafter. Persons with chronic lymphocytic leukemia have poor humoral immunity even early in the disease course and rarely respond to vaccines.

Household contacts of severely immunocompromised patients may be given live-virus vaccines such as yellow fever, MMR, or varicella vaccine but should not be given live intranasal influenza vaccine.

Considerations for Certain Vaccines

Yellow Fever Vaccine

Severely immunosuppressed travelers should be strongly discouraged from travel to destinations that present true risk of yellow fever. If travel to a yellow fever-endemic zone by such individuals is unavoidable and the vaccine is not given, travelers should be instructed carefully in methods to avoid mosquito bites and should be provided a vaccination waiver letter. If international travel requirements and not true exposure risk are the only reasons to vaccinate an asymptomatic HIV-infected person or a person with a limited immune deficit, the physician should provide a waiver letter on letterhead stationery. Travelers should be warned that vaccination waiver documents may not be accepted by some countries and that if the waiver is rejected, the option of deportation might be preferable to yellow fever vaccination at the destination. Patients with limited immune deficits or asymptomatic HIV should be offered the choice of vaccination and monitored closely for possible adverse effects. As vaccine response may be suboptimal, such vaccines are candidates for serologic testing 1 month post-vaccination. (For information about serologic testing, contact a state health department or the CDC Division of Vector-Borne Diseases [970] 221-6400.) Diligent insect precautions are similarly recommended in this situation. Despite the theoretical risk for neuroinvasion and encephalitis due to vaccine, there are no reports of clinical or epidemiologic studies to evaluate the risk of yellow fever vaccination among severely immunocompromised recipients.

Hib Vaccine

This vaccine is recommended or should be considered for many categories of compromised host. Normally only one dose is recommended for persons older than 5 years of age. This dose may be insufficient to induce immunity in immuno-suppressed persons, but the data are insufficient to recommend more than one dose.

Meningococcal Vaccines

Either one of the two vaccines should be considered for individuals who have a variety of compromising conditions, such as asplenia or complement deficiencies. The traveler's primary health-care provider should participate in the decision making in such situations.

Pneumococcal Polysaccharide Vaccine

This vaccine is recommended for many categories of compromised host, followed by a single booster. Data are insufficient on the use of pneumococcal conjugate vaccine to recommend its use in compromised older children and adults.

Influenza Vaccine

Influenza is a year-round infection in the tropics, and in the Southern Hemisphere the influenza season is April through September. Immunocompromised patients should be protected according to influenza risk at the destination; they should not be given live intranasal influenza vaccine.

Prevention and Self-Treatment of Infections

Travelers with symptomatic HIV or severe non-HIV immunocompromise are at risk for increased severity of some diseases.

Enteric Infections

The risk for foodborne and waterborne infections among immunosuppressed persons is amplified during travel to developing countries. Many enteric infections, such as those caused by Salmonella, Campylobacter, and Cryptosporidium, can be very severe or become chronic in immunocompromised persons.

Foods and beverages, specifically raw fruits and vegetables, raw or undercooked seafood or meat, tap water, ice made with tap water, unpasteurized milk and dairy products, and items purchased from street vendors, may be contaminated. Immunocompromised travelers need to be extraordinarily diligent in adhering to the food and water precautions recommended for all travelers. Waterborne infections might result from swallowing water during recreational activities. To reduce the risk for cryptosporidiosis and giardiasis, patients should avoid swallowing water during swimming and should not swim in water that might be contaminated (e.g., with sewage or animal waste). Attention to hand hygiene, including frequent and thorough hand washing, is the best prevention against gastroenteritis and is especially important on cruise ships. Hands should also be washed after any contact with animals, particularly young ones, or their living areas. Since diarrhea is a frequent complication of highly active antiretroviral therapy for HIV, such patients should receive counseling regarding the symptoms of enteric infections. Travelers’ diarrhea is a frequent problem of immunosup-pressed travelers, as it is in the general traveling population; however antibiotic prophylaxis is not routinely recommended.

Malaria

Meticulous malaria prevention should always be advised, as for immunocompetent travelers. Risk of malaria acquisition and severity of malaria are increased in HIV-infected individuals. Malaria infection increases HIV viral load and thus may exacerbate disease progression. Both atovaquone and mefloquine have theoretical potential for competition with protease inhibitors for metabolic enzymes (e.g., cytochrome P450) in the liver, but published evidence for clinically significant interaction is lacking. For malaria treatment, the use of quinidine (and by implication quinine) in patients taking nelfinavir or ritonavir is contraindicated because of potential cumulative cardiotox-icity. However, if a patient has severe and complicated malaria, there may be no choice. In these circumstances, as in others, quinidine should be used only with close monitoring. In addition, very careful monitoring should accompany quinidine therapy in those taking amprenivir, delaviridine, or the lopinavir/ritonavir combination. Ritonavir and ritonavir containing combination drugs that do not require refrigeration are now available. Several protease inhibitors have been shown in laboratory testing to inhibit the growth of malaria parasites. Asplenic individuals may be at greater risk of acquisition and complications of malaria.

Reducing Risk for Other Diseases

Travelers should be informed about other region-specific risks and instructed in ways to reduce those risks. Sexual activity increases during travel. Safer sex should be reinforced. HIV-infected individuals may still acquire Hepatitis B or C, or, rarely, a superinfection with a nonclade B HIV strain. Geographically focal infections that pose an increased risk of severe outcome for immunocompromised persons include visceral leishmaniasis (a protozoan infection transmitted by the sandfly) and several inhalationally acquired fungal infections (e.g., Penicillium marneffei infection in Southeast Asia and coccidioidomycosis in the Americas).

Many developing areas have high rates of tuberculosis, and obtaining a baseline tuberculin skin test should be considered. Patients with advanced HIV and transplant recipients are frequently taking either primary or secondary prophylaxis for one or more opportunistic infections (e.g., pneumocystis, mycobacteria, and toxoplasma). Complete adherence to all indicated regimens should be confirmed before travel.

General Preparation: Practical Considerations

  • Identify specific sources of medical care at the destination before departure and seek medical attention promptly when ill.
  • Avoid changes in the medication regimen shortly before travel to ensure that no side effects or complications of a new regimen occur while traveling.
  • Verify medical insurance coverage, purchase additional travel insurance if necessary and possible, and understand that many policies will not cover preexisting conditions such as HIV.
  • Carry an oversupply of medications, along with copies of prescriptions. Medications should be divided between carry-on and checked baggage, as either one can be lost or stolen. Long-stay travelers should ensure the availability of adequate medication at the destination or a reliable source for its importation.
  • HIV-positive travelers should be informed that many countries restrict entry of travelers with HIV infection. Antiretroviral drugs found in baggage at customs may lead to exclusion. Many countries require HIV antibody testing for students, workers, and others applying for long-term entry permits. Travelers should ascertain whether tests conducted in their home countries before travel will be accepted.
  • Seek medical assistance early in case of any febrile illness while in a developing country. Asplenic or functionally asplenic patients are predisposed to rapidly overwhelming sepsis with encapsulated bacteria. If competent medical help is not readily available, febrile asplenic patients should carry a broad-spectrum antibiotic such as levofloxacin to initiate self-therapy immediately. Widespread bacterial resistance now precludes most clinicians from recommending oral penicillins.

PREGNANCY AND TRAVEL

Factors Affecting the Decision to Travel Before and During Pregnancy

Reproductive-aged women who may be planning both pregnancy and international travel should consider preconceptional immunization, when practical, to prevent disease in the offspring. Since as many as 50% of pregnancies are unplanned, reproductive-aged women should consider maintaining current immunizations during routine checkups in case an unplanned pregnancy coincides with a need to travel. Preconceptional immunizations are preferred to vaccination during pregnancy, because they decrease risk to the unborn child. A woman should defer pregnancy for at least 28 days after receiving live vaccines (e.g., MMR, yellow fever), because of theoretical risk of transmission to the fetus. However, no harm to the fetus has been reported from the unintentional administration of these vaccines during pregnancy, and pregnancy termination is not recommended after an inadvertent exposure. Vaccination of susceptible women during the postpartum period, especially for rubella and varicella, is another opportunity for prevention, and these vaccines should be encouraged and administered (even for breastfeeding mothers) before discharge from the hospital.

According to the American College of Obstetrics and Gynecology, the safest time for a pregnant woman to travel is during the second trimester (18-24 weeks), when she usually feels best and is in least danger of spontaneous abortion or premature labor. A woman in the third trimester should be advised to stay within 300 miles of home because of concerns about access to medical care in case of problems such as hypertension, phlebitis, or premature labor. Pregnant women should be advised to consult with their health-care providers before making any travel decisions. Collaboration between travel health experts and obstetricians is helpful in weighing benefits and risks based on destination and recommended preventive and treatment measures. Table 9-2 lists relative contraindications to international travel during pregnancy (2,3). In general, pregnant women with serious underlying illnesses should be advised not to travel to developing countries.

Preparation for Travel During Pregnancy

Once a pregnant woman has decided to travel, a number of issues need to be considered before her departure.

  • An intrauterine pregnancy should be confirmed by a clinician and ectopic pregnancy excluded before beginning any travel.
  • Health insurance should provide coverage while abroad and during pregnancy. In addition, a supplemental travel insurance policy and a prepaid medical evacuation insurance policy should be obtained, although most may not cover pregnancy-related problems.
  • Check medical facilities at the destination. For a woman in the last trimester, medical facilities should be able to manage complications of pregnancy, toxemia, and cesarean sections.
  • Determine beforehand whether prenatal care will be required abroad and, if so, who will provide it. The pregnant traveler should also make sure prenatal visits requiring specific timing are not missed.
  • Determine, before traveling, whether blood is screened for HIV and hepatitis B at the destination. The pregnant traveler should also be advised to know her blood type, and Rh-negative pregnant women should receive the anti-D immune globulin (a plasma-derived product) prophylactically at about 28 weeks’ gestation. The immune globulin dose should be repeated after delivery if the infant is Rh positive.

General Recommendations for Travel

A pregnant woman should be advised to travel with at least one companion; she should also be advised that, during her pregnancy, her level of comfort may be adversely affected by traveling. Typical problems of pregnant travelers are the same as those experienced by any pregnant woman: fatigue, heartburn, indigestion, constipation, vaginal discharge, leg cramps, increased frequency of urination, and hemorrhoids (3). During travel, pregnant women can take preventive measures including avoidance of gas-producing food or drinks before scheduled flights (entrapped gases can expand at higher altitudes) and periodic movement of the legs (to decrease venous stasis) (3). Pregnant women should always use seatbelts while seated, as air turbulence is not predictable and may cause significant trauma.

Signs and symptoms that indicate the need for immediate medical attention are vaginal bleeding, passing tissue or clots, abdominal pain or cramps, contractions, ruptured membranes, excessive leg swelling or pain, headaches, or visual problems.

Greatest Risks for Pregnant Travelers

Motor vehicle accidents are a major cause of morbidity and mortality for pregnant women. When available, safety belts should be fastened at the pelvic area. Lap and shoulder restraints are best; in most accidents, the fetus recovers quickly from the safety belt pressure. However, even after seemingly mild blunt trauma, a physician should be consulted.

Hepatitis E, which is not vaccine preventable, can be especially dangerous for pregnant women, for whom the case-fatality rate is 17%-33%. Therefore, pregnant women should be advised that the best preventive measures are to avoid potentially contaminated water and food, as with other enteric infections.

Scuba diving should be avoided in pregnancy because of the risk of decompression syndrome in the fetus.

Specific Recommendations for Pregnancy

Air Travel During Pregnancy

Commercial air travel poses no special risks to a healthy pregnant woman or her fetus. The American College of Obstetricians and Gynecologists (ACOG) states that women with healthy, single pregnancies can fly safely up to 36 weeks’ gestation. The lowered cabin pressures (kept at the equivalent of 1,524-2,438 meters [5,000-8,000 feet]) affect fetal oxygenation minimally because of the favorable fetal hemoglobin-oxygen dynamics. If required for some medical indications, supplemental oxygen should be arranged in advance. Severe anemia, sickle-cell disease or trait, or history of thrombophlebitis are relative contrain-dications to flying. Pregnant women with placental abnormalities or risks for premature labor should avoid air travel. Each airline has policies regarding pregnancy and flying; it is always safest to check with the airline when booking reservations, because some will require medical forms to be completed. Domestic travel is usually permitted until the pregnant traveler is in week 36 of gestation, and international travel may be permitted until weeks 32-35, depending on the airline. A pregnant woman should be advised always to carry documentation stating the expected day of delivery.

Airport security radiation exposure is minimal for pregnant women and has not been linked to an increase in adverse outcomes for unborn children to date. However, because of early reports of a possible association of radiation exposure during pregnancy and subsequent increased risk of childhood leukemia and cancer, a pregnant passenger may request a hand or wand search rather than being exposed to the radiation of the airport security machines.

An aisle seat at the bulkhead will provide the most space and comfort, but a seat over the wing in the midplane region will give the smoothest ride. A pregnant woman should be advised to walk every half hour during a smooth flight and flex and extend her ankles frequently to prevent phlebitis. The safety belt should always be fastened at the pelvic level. Dehydration can lead to decreased placental blood flow and hemoconcentration, increasing risk of thrombosis. Thus, pregnant women should drink plenty of fluids during flights. For pregnant flight attendants and pilots, working air travel is restricted by most airlines by 20 weeks gestation.

Travel to High Altitudes During Pregnancy

Acclimatization responses at altitude act to preserve fetal oxygen supply, but all pregnant women should avoid altitudes higher than 3,658 meters (12,000 feet). In addition, altitudes higher than 2,500 meters (8,200 feet) should be avoided in late or high-risk pregnancy. Pregnant women who must travel to high altitude should postpone exercise until acclimatized.

Food- and Waterborne Illness During Pregnancy

It is especially important for pregnant women to adhere strictly to food and water precautions in developing countries because the consequences may be more severe than diarrhea and may have serious sequelae (e.g., toxoplasmosis, listeriosis).

Suspect drinking water should be boiled to avoid long-term use of iodine-containing purification systems. Iodine tablets can probably be used for travel up to several weeks, but congenital goiters have been reported in association with administration of iodine-containing drugs during pregnancy. Oral rehydration is the mainstay of therapy for travelers’ diarrhea. Bismuth subsalicylate compounds are contraindicated because of the theoretical risks of fetal bleeding from salicylates and teratogenicity from the bismuth.

The combination of kaolin and pectin may be used, and loperamide should be used only when necessary. The antibiotic treatment of travelers’ diarrhea during pregnancy can be complicated. Azithromycin or an oral third-generation cephalosporin may be the best options for treatment if an antibiotic is needed.

Malaria During Pregnancy

Malaria in pregnancy carries significant morbidity and mortality for both the mother and the fetus. Pregnant women should be advised to avoid travel to malaria-endemic areas if possible. Women who do choose to go to malarious areas can reduce their risk of acquiring malaria by following several preventive approaches. Because no preventive method is 100% effective, they should seek care promptly if symptoms of malaria develop. Pregnant women traveling to malarious areas should 1) remain indoors between dusk and dawn, if mosquitoes are active outdoors during this time; 2) if outdoors at night, wear light-colored clothing, long sleeves, long pants, and shoes and socks; 3) stay in well-constructed housing with air-conditioning and/or screens; 4) use permethrin-impregnated bed nets; and 5) use insect repellents containing DEET as recommended for adults, sparingly, but as needed. Pyrethrum-containing house sprays may also be used indoors if insects are a problem. If possible, remaining in cities or areas of cities that are at low (or lower) risk for malaria can help reduce the chances of infection. Pregnant travelers should be under the care of providers knowledgeable in the care of pregnant women in tropical areas.

For pregnant women who travel to areas with chloroquine-sensitive Plasmodium falciparum malaria, chloroquine has been used for malaria chemoprophylaxis for decades with no documented increase in birth defects. For pregnant women who travel to areas with chloroquine-resistant P. falciparum, mefloquine should be recommended for chemoprophylaxis during the second and third trimesters. For women in their first trimester, most evidence suggests that mefloquine prophylaxis causes no significant increase in spontaneous abortions or congenital malformations if taken during this period.

Because there is no evidence that chloroquine and meflo-quine are associated with congenital defects when used for prophylaxis, CDC does not recommend that women planning pregnancy need to wait a specific period of time after their use before becoming pregnant. However, if women or their health-care providers wish to decrease the amount of antimalarial drug in the body before conception, After two, four, and six half-lives, approximately 25%, 6%, and 2% of the drug remain in the body.

Doxycycline and primaquine are contraindicated for malaria prophylaxis during pregnancy, because both may cause adverse effects on the fetus. Malaria must be treated as a medical emergency in any pregnant traveler. A woman who has traveled to an area that has chloroquine-resistant strains of P. falciparum should be treated as if she as illness caused by chloroquine-resistant organisms. Because of the serious nature of malaria, quinine or intravenous quinidine should be initiated, and the case should be managed in consultation with an infectious disease or tropical medicine specialist. The management of malaria in a pregnant woman should include frequent blood glucose determinations and careful fluid monitoring: these requirements may necessitate intensive care supervision.

IMMUNIZATIONS

Risk to a developing fetus from vaccination of the mother during pregnancy is primarily theoretical. No evidence exists of risk from vaccinating pregnant women with inactivated virus or bacterial vaccines or toxoids. The benefits of vaccinating pregnant women usually outweigh potential risks when the likelihood of disease exposure is high, when infection would pose a risk to the mother or fetus, and when the vaccine is unlikely to cause harm.

The following information is intended for women who may require immunizations during pregnancy. Pregnant travelers may visit areas of the world where diseases eliminated by routine vaccination in the United States are still endemic and therefore may require immunizations before travel.

Bacille Calmette-Guérin (BCG)

BCG vaccine, used outside the United States for the prevention of tuberculosis, can theoretically cause disseminated disease and thus affect the fetus. Although no harmful effects to the fetus have been associated with BCG vaccine, its use is not recommended for U.S. travelers. Skin testing for tuberculosis exposure before and after travel is preferable when the risk is high.

Diphtheria-Tetanus (+/-Pertussis)

The combination diphtheria-tetanus primary series immunization should be given if the pregnant traveler has not been immunized or is only partially immunized. Previously vaccinated pregnant women who have not received a Td vaccination within the previous 10 years should receive a booster dose. However, if they have not received one dose of Tdap as an adult, this preparation should be used instead of Td. Although no evidence suggests teratogenicity with tetanus or diphtheria toxoids or with the use of Tdap, the preference would be for either of their administration to occur during the second or third trimester.

Hepatitis A

HAV is usually no more severe during pregnancy than at other times and does not affect the outcome of pregnancy. There have been reports, however, of acute fulminant disease in pregnant women during the third trimester, when there is also an increased risk of premature labor and fetal death. These events have occurred in women from developing countries and might have been related to underlying malnutrition.

HAV is rarely transmitted to the fetus, but transmission can occur during viremia or from fecal contamination at delivery.

Hepatitis B

The hepatitis B vaccine may be administered during pregnancy and is recommended for pregnant women at risk for hepatitis B virus infection.

Immune Globulin Preparations

No known fetal risk exists from passive immunization of pregnant women with immune globulin preparations. Administration of IG can be used pre-exposure as protection against hepatitis A or for postexposure management for other viral diseases if warranted.

Influenza

Because of the increased risk for influenza-related complications, women who will be pregnant during the influenza season of their travel destination should be vaccinated with inactivated vaccine, when vaccine is available. Vaccine can be administered in any trimester and is especially recommended for those with chronic diseases and an increased risk of influenza-related complications. Data from influenza immunization with inactivated vaccine of more than 2,000 pregnant women have not demonstrated an association with adverse fetal effects. Live attenuated influenza vaccines (LAIV), such as certain nasal preparations, are contraindicated during pregnancy.

Japanese Encephalitis

No information is available on the safety of Japanese encephalitis vaccine during pregnancy. It should not be routinely administered during pregnancy. Pregnant women who must travel to an area where the risk of JE is high should be vaccinated when the theoretical risks are outweighed by the risk of infection to the mother and developing fetus.

Measles, Mumps, and Rubella

The measles vaccine, as well as the measles, mumps, and rubella (MMR) vaccines in combination, are live-virus vaccines and are contraindicated in pregnancy (9,10). However, the Vaccine in Pregnancy Registry recently documented that no evidence of congenital rubella syndrome occurred in the offspring of more than 200 women who received rubella vaccine 3 months before to 3 months after conception. Rubella-susceptible women who are pregnant should be counseled about the potential risk for congenital rubella syndrome and the importance of being vaccinated after they are no longer pregnant. Because of the increased incidence of measles in children in developing countries and because of measles’ communicability and potential for causing serious consequences in adults, susceptible women should delay traveling until after delivery, when immunization can be given safely. If an unprotected (without a history of physician-diagnosed measles or without at least two doses of measles vaccine) pregnant woman has a documented exposure to measles, IG should be given within 6 days to prevent illness.

Meningococcal Meningitis

The polyvalent meningococcal meningitis vaccine (MPSV4) can be administered during pregnancy if the woman is entering an area where the disease is epidemic. Studies of vaccination during pregnancy have not documented adverse effects among either pregnant women or neonates and have shown the vaccine to be efficacious. Based on data from studies involving the use of the polysaccharide meningococcal vaccines administered during pregnancy, altering meningococcal vaccination recommendations during pregnancy is unnecessary. The conjugate (MCV4) meningococcal vaccine is safe and immunogenic among nonpregnant persons ages 11-55, but no data are available on the safety of MCV4 during pregnancy. Women of childbearing age who become aware that they were pregnant when they received MCV4 vaccination should contact their health-care provider or the vaccine manufacturer.

Pneumococcal (PPV23)

The safety of pneumococcal polysaccharide vaccine during the first trimester of pregnancy has not been evaluated, although no adverse fetal consequences have been reported after inadvertent vaccination during pregnancy. Women with chronic diseases (such as asplenia or metabolic, renal, cardiac, or pulmonary diseases), smokers, and immunosuppressed women should consider vaccination.

Poliomyelitis

There is no convincing evidence of adverse effects of inactivated poliovirus vaccine in pregnant women or developing fetuses. However, if not previously immunized, a pregnant woman traveling to an area where polio still occurs should be advised to have at least two doses of vaccine one month apart before departure, in accordance with the recommended schedules for adults. The pregnant traveler who is not protected against poliomyelitis has increased risks to both herself and her unborn fetus.

Paralytic disease can occur with greater frequency when infection develops during pregnancy. Anoxic fetal damage has also been reported, with up to 50% mortality in neonatal infection.

Rabies

Because of the potential consequences of inadequately treated rabies exposure and because there is no indication that fetal abnormalities have been associated with cell culture rabies vaccines, pregnancy is not considered a contraindication to rabies postexposure prophylaxis. If the risk of exposure to rabies is substantial, preexposure prophylaxis may also be indicated during pregnancy.

Typhoid

No data are available on the use of either typhoid vaccine in pregnancy. The Vi capsular polysaccharide vaccine (ViCPS) injectable preparation is the vaccine of choice during pregnancy because it is inactivated and requires only one injection. The oral Ty21a typhoid vaccine is not absolutely contraindicated during pregnancy, but it is live attenuated and thus has theoretical risk.

Varicella

Women who are pregnant or planning to become pregnant should not receive the varicella vaccine. Nonimmune pregnant women should consider postponing travel until after delivery when the vaccine can be given safely. Varicella zoster immune globulin (VZIG) should be strongly considered within 96 hours of exposure for susceptible, pregnant women who have been exposed. However, VZIG may not be readily available.

Yellow Fever

The safety of yellow fever vaccination during pregnancy has not been established, and the vaccine should be administered to a pregnant woman only if travel to an endemic area is unavoidable and if an increased risk for exposure exists. In these instances, the vaccine should be administered, and infants born to these women should be monitored closely for evidence of congenital infection and other possible adverse effects resulting from yellow fever vaccination. Further, serologic testing to document an immune response to the vaccine can be considered, because the seroconversion rate for pregnant women may be lower than in other healthy adults.

If traveling to or transiting regions within a country where the disease is not a current threat but where policy requires a yellow fever vaccination certificate, pregnant travelers should be advised to carry a physician's waiver, along with documentation (of the waiver) on the immunization record.

The Travel Health Kit During Pregnancy

Additions and substitutions to the usual travel health kit need to be made during pregnancy. Talcum powder, a thermometer, oral rehydration salt packets, prenatal vitamins, an antifungal agent for vaginal yeast, acetaminophen, and a sunscreen with a high SPF should be carried. Women in the third trimester may be advised to carry a blood-pressure cuff and urine dipsticks so they can check for pro-teinuria and glucosuria, both of which would require prompt medical attention. Antimalarial and antidiarrheal self-treatment medications should be evaluated individually, depending on the traveler's itinerary and her health history. Most medications should be avoided, if possible.

BREASTFEEDING AND TRAVEL

Deciding About Travel and Breastfeeding

Travel need not be a reason to stop breastfeeding. A mother traveling with a nursing infant may find breast-feeding makes travel easier than it would be if traveling with a formula-fed infant. A mother traveling without her nursing infant or child may take steps to preserve breast-feeding and maintain her milk supply while separated. The major factors for a mother traveling without her nursing infant or child to consider are the amount of time she has to prepare for her trip, her flexibility of time while traveling, her options for storing expressed milk while traveling, the duration of her travel, and her destination. Mothers planning travel away from a nursing infant may access information from her pediatrician or from an International Board-Certified Lactation Consultant (IBCLC). Mothers may find an IBCLC in their area at http://gotwww.net/ilca/ or http://www.iblce.org/old/.

A mother who travels without her nursing infant or child may find her milk supply somewhat diminished upon her return. This does not need to be a reason to stop breastfeeding. A mother who returns to her nursing infant or child can continue breastfeeding and supplement as needed until her milk supply returns to its prior level. Often, after returning from travel, a nursing infant or child will help bring her milk supply to its prior level. Occasionally, however, nursing infants or children who are separated from their mother for an extended time have difficulty transitioning back to breastfeeding.

Preparation for Travel While Breastfeeding

Breastfeeding mothers may wish to find local breastfeeding support before beginning travel and keep pertinent contact information handy throughout the trip. La Leche League International has breastfeeding experts in many countries (http://www.lalecheleague.org).

A mother traveling with a nursing infant younger than 6 months old need not plan to supplement breastfeeding because of travel. Breastfed infants do not require water supplementation, even in extreme heat environments. While traveling, the best way to both maintain a mother's milk supply and ensure ideal nutrition and hydration for the child is frequent, unrestricted nursing opportunities. Breastfeeding also protects the infant from water that is possibly contaminated.

A breastfeeding mother traveling without her nursing infant or child may wish to produce and store a supply of milk to be fed to the infant or child during her absence by another caregiver. Building a supply to be fed in her absence takes time and patience and is most successful when begun gradually, many weeks in advance of her departure. It is also important to consider that infants who have never consumed milk from a bottle or cup need opportunities to practice this skill with another caregiver prior to the mother's departure.

Maintaining Lactation During Travel

A breastfeeding mother traveling without her nursing infant or child who does not build a supply of milk to be fed in her absence can still maintain her milk supply while she is traveling. These efforts will help maintain her breast-feeding relationship for when she and her infant or child can be together again.

Milk expression approximately every 3-4 hours for infants less than 6 months old, less frequently for older infants and children, helps a mother maintain her milk supply and provides milk that she may choose to bring home for her infant or child. A mother who will be separated from her infant or child for a long period of time while traveling might have a difficult time maintaining lactation. In general, separation of a week or less does not pose a major problem for a mother wishing to maintain breastfeeding while separated from her infant or child. This time is more flexible as the child becomes older and complementary foods play a larger role in the child's diet.

Depending on her destination, a mother may need to plan for milk expression without a reliable electrical power source. Expressing milk without an electrical power source is less reliable for maintaining milk supply over a long period of time than expressing milk with a hospital-grade electric breast pump. Intermittent milk expression can be successful with battery and manual breast pumps, as well as manual (hand) expression. Manual (hand) expression is the most hygienic way to collect milk. Mothers planning on travel to locations without reliable electrical power should learn and practice manual expression techniques well before travel is to begin.

The destination for travel can impact decisions for milk storage. Expressed milk should be stored in clean, tightly sealed containers. Any container that may be cleaned well with hot, soapy water and that seals tightly and reliably may be used. Once milk is cooled, a cold chain needs to be maintained until the milk is consumed. Refrigerated milk can subsequently be frozen; however, once frozen milk is fully thawed, it should be used within 1 hour.

Handling expressed breast milk does not require special medical precautions. Breast milk may be stored in any refrigerator or other location where other foods would be safe and may be stored with other foods. Breast milk requires no special labeling, it is not considered a biohazard, and the universal precautions for prevention of transmission of human immunodeficiency virus, hepatitis B virus, and other blood borne pathogens (known widely as “Universal Precautions”) do not apply to it.

Immunizations for Breastfeeding Mothers During Travel

Most nursing mothers may be immunized routinely, based on recommendations for the specific travel itinerary. Neither inactivated nor live vaccines administered to a lactating woman affect the safety of breast-feeding for mothers or infants. Breast-feeding does not adversely affect immunization and is not a contraindication for any vaccine. However, there is a theoretical risk to the infant with the use of yellow fever vaccine in breastfeeding mothers. Vaccination of nursing mothers should be avoided because of the theoretical risk for the transmission of 17D virus to the breastfed infant. When travel of nursing mothers to high-risk yellow fever-endemic areas cannot be avoided or postponed, such persons can be vaccinated. Breastfed infants should be vaccinated according to routine recommended schedules.

Medications for Breastfeeding Mothers During Travel

Breastfeeding mothers should take the usual adult dose of the antimalarial drug appropriate for the itinerary. Nursing mothers with infants weighing less than 5 kg (approximately 11 pounds) should not take atovaquone/proguanil (Malarone) for prophylaxis. Data are limited on the use of doxycycline during breastfeeding; however, most experts consider its short-term use compatible with breastfeeding. Primaquine is contraindicated during lactation unless both the mother and breastfed infant have normal G6PD levels. It is critical to note that breastfed infants require their own antimalarial medication if traveling to an endemic area. Mother's milk does not provide malaria protection, even when the mother is taking an adequate medication and dose for herself.

Traveling with a Breastfed Infant

A mother traveling with a nursing infant or child may wish to consider a sling or other soft infant carrier for use while traveling. This helps maintain breast-feeding by increasing opportunities for unrestricted nursing and increasing skin-to-skin contact with the child, while also protecting the child from environmental hazards and easing the burden of carrying a child. Infants are particularly susceptible to painful pressure due to eustachian tube collapse as a result of pressure changes during air travel. Breastfeeding during ascent and descent often relieves this discomfort.

X rays used in airport screenings have no effect on breast-feeding, breast milk, or the process of lactation. Expressed breast milk does not need to be declared at US Customs when returning to the United States. However, recommendations regarding the carrying of liquids on board aircraft are subject to change and should be checked prior to travel. Breast pumps are usually considered personal items during air travel and may be carried on and stowed underneath the passenger seat, similar to a laptop computer, purse, or diaper bag. It is always prudent to check current airline security guidelines.

A nursing mother with travelers’ diarrhea should increase her own fluid intake and frequency of breastfeeding; she should not stop breastfeeding because of travelers’ diarrhea. Breastfed infants are protected from travelers’ diarrhea both because breastfeeding protects them from consuming contaminated items and because a nursing mother does not pass on travelers’ diarrhea to her infant via breastfeeding. The use of oral rehydration salts (ORS) is fully compatible with breastfeeding.

In addition to the usual contents of the travel health kit, breastfeeding mothers may wish to include an antifungal cream, which can be used to treat periareolar yeast infections.

VACCINE RECOMMENDATIONS FOR INFANTS AND CHILDREN

For all children, decisions regarding vaccinations should be made in cooperation with a health-care provider who will review the traveler's medical history and itinerary. Each traveler should be up to date with their routine child-hood vaccinations because many of the diseases prevented by these vaccines are rare or non-existent in the United States but are still common in other parts of the world. Proof of yellow fever vaccination is required for entry into certain countries. Recommendations for other vaccines and immunobiologics depend on the traveler's medical history and itinerary and do not alter the schedule for recommended childhood immunizations. More information on specific recommendations can be found on the CDC website at wwwn.cdc.gov/travel.

Modifying the Immunization Schedule for Inadequately Immunized Infants and Younger Children Before International Travel

Several factors influence recommendations for the age at which a vaccine is administered, including age-specific risks of the disease and its complications, the ability of people of a given age to develop an adequate immune response to the vaccine, and potential interference with the immune response by passively transferred maternal antibody. Vaccines are recommended for the youngest age group at risk for developing the disease whose members are known to develop an adequate antibody response to vaccination.

The routine immunization recommendations and schedules for infants and children in the United States do not provide specific guidelines for those traveling internationally before the age when specific vaccines and toxoids are routinely recommended. When deciding when to travel with a young infant or child, parents should be advised that the earliest opportunity to receive routinely recommended immunizations in the United States (except for the dose of hepatitis B vaccine at birth) is at 6 weeks of age. Because additional vaccinations may be recommended for international travel, parents should also be aware of the youngest age at which these vaccinations can be administered. The following section provides guidance for active and passive immunization of such infants and children.

Routine Infant and Childhood Vaccinations

Hepatitis B Vaccine

Hepatitis B virus (HBV) is a cause of acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. There are more than 200 million chronically infected persons worldwide; the risk of chronic infection is highest when infection occurs in infancy or childhood and declines with age. Infants and children who have not previously been vaccinated and who are traveling to areas with intermediate and high HBV endemicity are at risk if they are directly exposed to blood (or body fluids containing blood) from the local population. Circumstances in which HBV transmission could occur in children include receipt of blood transfusions not screened for HBV surface antigen (HBsAg), exposure to unsterilized medical or dental equipment, or continuous close contact with local residents who have open skin lesions (impetigo, scabies, or scratched insect bites).

Hepatitis B vaccine is recommended for all infants in the United States, with the first dose administered soon after birth and before hospital discharge (3). Infants and children who will travel should receive the three doses of HBV vaccine before traveling. The interval between doses one and two should be at least 4 weeks. Between doses two and three, the interval should be a minimum of 8 weeks; the interval between doses one and three should be at least 16 weeks. The third dose should not be given before the infant is at least 24 weeks of age. Adolescents not previously vaccinated with hepatitis B vaccine should be vaccinated at 11-12 years of age. For adolescents, the usual schedule is two doses separated by at least 4 weeks, followed by a third dose 4–6 months after the second dose.

Diphtheria and Tetanus Toxoid and Pertussis Vaccine

Diphtheria, tetanus, and pertussis each occur worldwide and are endemic in countries with low immunization levels. Infants and children leaving the United States should be immunized before traveling. Optimum protection against diphtheria, tetanus, and pertussis is achieved with at least three but preferably four doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP). The usual primary series includes four doses given at 2, 4, 6, and 15-18 months of age. A fifth (booster) dose is recommended when the child is 4–6 years of age. The fifth dose is not necessary if the fourth dose in the primary series was given after the child's fourth birthday. For infants and children younger than 7 years of age, if an accelerated schedule is required to complete the series before travel, the schedule may be started as soon as the infant is 6 weeks of age, with the second and third doses given 4 weeks after each preceding dose. The fourth dose should not be given before the infant is 12 months of age and should be separated from the third dose by at least 6 months. The fifth (booster) dose should not be given before the child is 4 years of age. Two doses of DTaP received at intervals at least 4 weeks apart can provide some protection; however, a single dose offers little protective benefit. Parents should be informed that infants and children who have not received at least three doses of DTaP might not be fully protected against pertussis.

Haemophilus influenzae Type b Conjugate Vaccine

Haemophilus influenzae type b (Hib) is an endemic disease worldwide that can cause fatal meningitis, epiglottitis, and other invasive diseases. Infants and children should have optimal protection before traveling. Routine Hib vaccination beginning at 2 months of age is recommended for all U.S. children. The first dose may be given when an infant is as young as 6 weeks of age. Vaccination before age 6 weeks may induce immune tolerance to subsequent vaccines and should never be done. A primary series consists of two or three doses (depending on the type of vaccine used) with a minimum interval of 4 weeks between doses. A booster dose is recommended when the infant is at least 12 months of age, at least 8 weeks after the previous dose.

If Hib vaccination is started when the infant or child is 7 months of age or older, fewer doses are required. If different brands of vaccine are administered, a total of three doses of Hib conjugate vaccine completes the primary series. After completion of the primary infant vaccination series, any of the licensed Hib conjugate vaccines may be used for the booster dose when the infant is 12-15 months of age.

If previously unvaccinated, infants younger than 15 months of age should receive at least two vaccine doses before travel. An interval as short as 4 weeks between these two doses is acceptable. Unvaccinated infants and children 15-59 months of age should receive a single dose of Hib vaccine. Children older than 59 months of age, adolescents, and adults do not need to be vaccinated unless a specific condition exists such as functional or anatomic asplenia, immunodeficiency, immunosuppression, or HIV infection.

Polio Vaccine

While polio has been eliminated in the US, poliovirus continues to circulate in parts of Africa and Asia, including South Asia. In the US, all infants and children should receive four doses of inactivated poliovirus vaccine (IPV) at 2, 4, 6-18 months, and 4–6 years of age. If accelerated protection is needed, the minimum interval between doses is 4 weeks. The minimum age for the fourth dose is 18 weeks. Infants and children who had initiated the poliovirus vaccination series with one or more doses of oral poliovirus vaccine (OPV) should receive IPV to complete the series. Proof of vaccination is required to enter Saudi Arabia for the Hajj.

Rotavirus Vaccine

Rotavirus is the most common cause of severe gastroenteritis in infants and young children worldwide. In developing countries rotavirus gastroenteritis is responsible for approximately 500,000 deaths per year among children younger than 5 years. Routine rotavirus vaccination beginning at about 2 months of age is recommended for all U.S. children. The first dose of the series must be administered between 6 and 12 weeks of age. The vaccination series should not be initiated for children 13 weeks of age or older because of a lack of safety data when the series is begun after 12 weeks of age. Two additional doses are recommended at 4 and 6 months of age. A minimum interval of 4 weeks between doses can be used if an accelerated schedule is needed. All three doses of the series should be administered no later than 32 weeks of age (about 712 months). Rotavirus vaccine should not be administered to infants older than 32 weeks of age even if the 3-dose series has not been completed.

Measles, Mumps, and Rubella Vaccine

Measles is an endemic disease in areas where measles immunization levels are low, and outbreaks occur even in developed countries. International travelers are at increased risk for measles exposure. Infants and children should be as well protected as possible against measles and should complete the immunization series before traveling. While the risk for serious disease in infants from either mumps or rubella is low, these diseases do circulate in many parts of the world and vaccination is recommended.

In addition to the measles, mumps, and rubella vaccine (MMR), monovalent measles, monovalent mumps, monovalent rubella, and combinations of the components are available from the manufacturer. A combined measles, mumps, rubella, and varicella vaccine (MMRV) was also licensed by the U.S. Food and Drug Administration in 2005 for children age 12 months-12 years. The Advisory Committee on Immunization Practices (ACIP) recommends that MMR be administered when any of the individual components is indicated as part of the routine immunization schedule (MMRV can be used if varicella vaccine is also indicated). Two doses of MMR are routinely recommended for all children, usually at age 12 months and again at age 4–6 years. The second dose can be given as soon as 28 days after the first dose. If MMRV is used, note that two varicella-containing vaccines should be separated by at least 3 months.

Before travel outside the U.S., children 12 months of age and older should receive two doses of MMR separated by at least 28 days. Children age 6-11 months, if they must travel outside the U.S., should receive monovalent measles vaccine before departure if it is available, or MMR if monovalent measles vaccine is not available. However, MMR given before age 12 months should not be counted as part of the series. Children who receive MMR before age 12 months will need two more doses of MMR, the first of which should be administered at 12 months of age.

Varicella Vaccine

Varicella (chickenpox) is an endemic disease throughout the world. Two doses of varicella vaccine are recommended for all susceptible children 12 months of age and older. The first dose is recommended at age 12-15 months. The second dose is routinely recommended at age 4–6 years but can be given earlier, provided that at least 3 months have passed since the first dose.

Efforts should be made to ensure varicella immunity before age 13 years, because varicella disease can be more severe among older children and adults. Children 13 years of age and older should receive two doses of varicella vaccine 4–8 weeks apart. Vaccination is not necessary for children with health care provider-diagnosed chickenpox. When a prior history of chickenpox is uncertain, the vaccine should be given.

Meningococcal Vaccine

Meningococcal disease (including meningococcal meningitis) is caused by the bacterium Neisseria meningitidis and has high morbidity and mortality rates. Epidemics occur in sub-Saharan Africa during the dry season (December through June) and CDC recommends travelers be vaccinated before traveling to this region. Meningococcal vaccination is a requirement to enter Saudi Arabia when traveling to Mecca during the annual Hajj.

Two vaccines are available in the U.S. that protect against four serotypes of N. meningitidis (A, C, Y, and W-135): the meningococcal conjugate vaccine (MCV4) and the meningococcal polysaccharide vaccine (MPSV4). MCV4 is approved for use in persons 11-55 years of age and is recommended by the ACIP for routine vaccination of adolescents at 11-12 years of age. MCV4 is also recommended for persons 11 years of age and older who travel to or reside in areas where N. meningitidis is hyperendemic or epidemic. MPSV4 can be used when MCV4 is not available and is recommended for children age 2-10 years going to these high-risk areas. The serogroup A polysaccharide in MPSV4 induces an antibody response in some children as young as 3 months. Thus, vaccinating infants traveling to high-risk areas can provide some degree of protection. For children vaccinated at younger than 4 years of age, revaccination in 2–3 years should be considered if they remain at high risk for infection. For children vaccinated at 4 years of age and older, revaccination should be considered in 5 years if they remain at high risk.

Pneumococcal Vaccine

Streptococcus pneumoniae causes substantial morbidity and mortality throughout the world each year. The vaccine is available in two forms: the pneumococcal conjugate vaccine (PCV7) and the pneumococcal polysaccharide vaccine (PPV23).

All infants should be vaccinated with PCV7. Infant vaccination provides the earliest protection, and infants younger than 23 months of age have the highest incidence of pneumococcal disease. The primary series for PCV7 includes three doses given at 2, 4, and 6 months of age with a fourth (booster) dose at 12-15 months of age. Children 24 months of age and older who are at high risk for pneumo-coccal disease (e.g., those with sickle cell disease, asplenia, HIV, chronic illness, or immunocompromising conditions) should receive a dose of PPV23 at least 2 months following their last dose of PCV7. If the child is 10 years of age or younger, one revaccination with PPV23 should be considered 3–5 years after the first dose of PPV 23.

Unvaccinated children 7-11 months of age should receive two doses of PCV7 at least 4 weeks apart and a booster dose at age 12-15 months. Unvaccinated children 12-23 months of age should receive two doses at least 8 weeks apart. Vaccination with a single dose of PCV7 should be considered for previously unvaccinated healthy children 24-59 months of age. Previously unvaccinated children 24-59 months of age at high risk for pneumococcal disease (as previously described) should receive two doses separated by at least 8 weeks. Children 24-59 months of age who are at increased risk for pneumococcal disease and who were previously vaccinated with PPV23 should receive two doses of PCV7 separated by at least 8 weeks. The PCV7 vaccine is not routinely recommended for children older than 59 months (5 years) of age.

Influenza Vaccine

Influenza vaccine can reduce the risk of influenza infection in transmission sea-son (typically November-February in the Northern Hemisphere, April-September in the Southern Hemisphere, and throughout the year in the tropics). The vaccine is prepared in two forms: an intramuscular trivalent inactivated vaccine (TIV) and a live, attenuated, intranasal vaccine (LAIV).

All children 6-59 months of age should receive TIV annually, as should all children at risk for complicated influenza infection due to chronic medical conditions, including but not limited to asthma, cardiac disease, sickle cell disease, HIV, and diabetes. In addition, all persons who have close contact with healthy children younger than 59 months of age (particularly infants younger than 6 months of age) or with persons at increased risk of influenza complications should be vaccinated annually. For healthy children 5 years of age and older, LAIV is an acceptable alternative to TIV. (LAIV can be given to healthy persons 5-49 years of age.)

Children receiving TIV should be administered an age-appropriate dose (0.25 mL for those 6-35 months of age and 0.5 mL for those 36 months of age and older). Children 8 years of age and younger who are receiving influenza vaccine for the first time should receive two doses (separated by at least 4 weeks for TIV and 6-10 weeks for LAIV). Children 9 years of age and older should receive one injection of the 0.5-mL dose.

Hepatitis A Vaccine or Immune Globulin for Hepatitis A

Hepatitis A virus (HAV) is endemic in most parts of the world, and infants and children traveling to these areas are at increased risk for acquiring HAV infection. Although HAV is often not severe in infants and children younger than 5 years of age, those infected efficiently transmit infection to older children and adults, who are at higher risk of severe disease.

Hepatitis A vaccine is recommended for all children at age 1 year (i.e., 12-23 months). Vaccination should be ensured for all susceptible children traveling to areas where there is an intermediate or high risk of HAV infection. The HAV vaccine series consists of two doses at least 6 months apart. The first dose should be administered 4 weeks before travel to allow time for an adequate immune response to develop. The second dose is necessary for long-term protection.

The vaccine is not approved for children younger than 1 year of age. Children less than 1 year of age who are traveling to high-risk areas should receive immune globulin (IG). For optimal protection, IG may also be given to children older than 1 year who will be traveling less than 4 weeks after receipt of the first dose of hepatitis A vaccine. The vaccine and IG can be administered at the same time at different anatomic sites.

IG does not interfere with the response to yellow fever vaccine but can interfere with the response to other live injected vaccines (e.g., measles, mumps, rubella (MMR), and varicella vaccines). Administration of MMR should be delayed for at least 3 months and varicella for more than 5 months after administration of IG. Moreover, IG should not be administered for 2 weeks after measles-, mumps-, and rubella-containing vaccines and for 3 weeks after vaccination with varicella vaccine. If IG is given during this time, the child should be revaccinated with the live vaccine at least 3 months after administration of IG. When travel plans do not allow adequate time for administration of live vaccines and IG before travel, the severity of the diseases and epidemiology of the diseases at destination points will help determine the most appropriate course of preparation.

Other Vaccines

Yellow Fever Vaccine

Yellow fever, a disease transmitted by mosquitoes, is endemic in certain areas of Africa and South America. Proof of yellow fever vaccination is required for entry into some countries.

Infants are at high risk for developing encephalitis from yellow fever vaccine, a live virus vaccine. Vaccination of infants should be considered on an individual basis. Although the incidence of these adverse events has not been clearly defined, 14 of 18 reported cases of post-vaccination encephalitis were in infants younger than 4 months old. One fatal case confirmed by viral isolation was in a 3-year-old child.

Travelers with infants younger than 9 months of age should be strongly advised against traveling to areas within the yellow fever-endemic zone. The ACIP recommends that yellow fever vaccine never be given to infants younger than 6 months of age. Infants 6–8 months of age should be vaccinated only if they must travel to areas of ongoing epidemic yellow fever and a high level of protection against mosquito bites is not possible. Infants and children older than 9 months of age can be vaccinated if they travel to countries within the yellow fever-endemic zone.

Physicians considering vaccinating infants younger than 9 months of age should contact the Division of Vector-Borne Infectious Diseases (970-221-6400) or the Division of Global Migration and Quarantine (404-498-1600) at CDC for advice.

Typhoid Vaccine

Typhoid fever is an acute, life-threatening febrile illness caused by the bacterium Salmonella enterica Typhi. Vaccination is recommended for travelers to areas where there is a recognized risk of exposure to S ser. Typhi.

Two typhoid vaccines are available: a Vi capsular polysaccharide vaccine (ViCPS) administered intramuscularly and an oral, live, attenuated vaccine (Ty21a). Both vaccines induce a protective response in 50%-80% of recipients. The ViCPS vaccine can be administered to children who are at least 2 years of age, with a booster dose 2 years later if continued protection is needed. The Ty21a vaccine, which consists of a series of four capsules ingested every other day, can be administered to children 6 years of age and older. All the capsules should be taken at least 1 week before potential exposure. A booster series for Ty21a should be taken every 5 years if indicated.

Because neither vaccine is fully protective, preventing contamination of food and beverages remains extremely important.

Japanese Encephalitis Vaccine

Japanese encephalitis (JE) is transmitted by primarily night-biting mosquitoes in rural areas of Asia and the Pacific Rim. In temperate climates, their numbers are greatest from June through September; they are inactive during the winter. Most reported cases occur in children. Although most infections are asymptomatic, when encephalitis occurs, the mortality rate can be as high as 30%; neu-rologic sequelae occur in 50% of survivors and are more common in the very young. The risk to short-term travelers and those who confine their travel to urban centers is very low. Expatriates and travelers living for prolonged periods in rural areas where JE is endemic or epidemic are at greatest risk. The decision to vaccinate a child should take into consideration the itinerary, expected activities, and level of JE activity in the country.

JE vaccine is administered as a series of three injections on days 0, 7, and 30. A booster dose is administered at least 24 months later. Children 1–2 years of age receive 0.5 mL of vaccine per dose; those 3 years of age and older receive 1.0 mL of vaccine per dose. No data are available on vaccine efficacy for infants younger than 1 year of age.

JE vaccine is associated with local reactions in approximately 20% of vaccines and mild systemic reactions (e.g., fever, headache, myalgias, and rash) in approximately 10%. Serious allergic reactions, including generalized urti-caria and angioedema of the extremities, face, and oropharynx have been reported in up to 0.6% of vaccines, with accompanying respiratory distress or hypotension in a small number of these cases. Importantly, these hypersensitivity reactions can be delayed for 1 to 2 weeks after receipt of the vaccine. Children receiving the vaccine series should be observed for 30 minutes after immunization. Moreover, the series should be completed at least 10 days before departure, and during that time, vaccine recipients should be remain in areas with access to medical care.

Rabies Vaccine

Rabies is an acute, fatal encephalomyelitis usually transmitted by the bite of an infected mammal. Rabies occurs throughout the world and is endemic in most countries. As with other vaccines, the decision to vaccinate will depend on the itinerary and expected activities during international travel. The decision should also be guided by the availability of appropriate antirabies biologics at the destination. Children should always be instructed to report all bites and to avoid contact with animals other than their own pets.

Two rabies vaccines are licensed for use in the United States. Each may be administered to infants and children. All the rabies vaccines, when used in a preexposure regimen, are given as a series of injections on days 0, 7, and 21 or 28. Even if a child has completed the preexposure vaccine series, any mammal bite warrants immediate medical evaluation to determine the need for postexposure immunization.

INTERNATIONAL ADOPTIONS

International adoptions bring a host of special considerations, as these adopted children come from diverse cultural backgrounds, living conditions, and medical histories. Adoptive families should be aware of the unique medical, nutritional, environmental and psychological issues they may face. Government and private websites provide information on travel advisories (http://www.cdc.gov/travel), legislation, country-specific adoption requirements and procedures, and many other resources. This summary is not meant to be comprehensive, since resources are constantly changing; it will serve merely as a starting point for information on international adoptions.

Adoptive Parents

Adoptive parents who travel overseas to pick up their child should visit a health-care provider or travel medicine specialist to ensure that their routine vaccinations are up to date and to obtain pre-travel advice tailored to their own medical history and the country they will visit. During travel, they need to take precautions regarding proper rest, food, water, and insect exposure to protect their own health, so that they can care for the child. Adoptive parents should be aware that unexpected complications in the adoption process may prolong their stay, and they should plan accordingly, especially if malaria prophylaxis or other important medication is needed. Recently, an outbreak of measles was identified among children being adopted from China and their family members. In 2002 and 2004, adoptions from the affected orphanages were temporarily suspended while Chinese authorities implemented measures to control and prevent further transmission of measles among adopted children (2-4). Prospective parents who are traveling internationally to adopt children, as well as their household contacts, should ensure that they have a history of natural disease or have been vaccinated against measles according to guidelines of the Advisory Committee on Immunization Practices (ACIP). All persons born after 1957 should receive two doses of measles-containing vaccine.

Overseas Medical Examinations for the Child

All immigrants, including infants and children adopted overseas by U.S. citizens, and all refugees coming to the United States must have a medical examination overseas by a physician designated by the Department of State. The medical examination focuses primarily on detecting certain serious contagious diseases that may be the basis for visa ineligibility. Prospective adoptive parents should be advised not to rely on this medical examination to detect all possible disabilities and illnesses. If an infant or a child is found to have an illness or disability that may make the child ineligible for a visa, a visa may still be issued after the illness has been adequately treated or after a waiver of the visa eligibility has been approved by the Bureau of Citizenship and Immigration Services. If the physician notes that the infant or child has a serious disease or disability, the prospective parent(s) will be notified and asked if they wish to proceed with the infant's or child's immigration.

The medical examination consists of a brief physical examination and a medical history. A chest radiograph examination for tuberculosis and blood tests for syphilis and HIV are required for immigrants 15 years of age and older. Applicants younger than 15 years of age are tested only if there is reason to suspect any of these diseases.

A new subsection of the U.S. Immigration and Nationality Act requires that any person seeking an immigrant visa for permanent residency must show proof of having received the vaccines recommended by ACIP before immigration. While this new subsection now applies to all immigrant infants and children entering the United States, internationally adopted children younger than 11 years of age have been exempted from the overseas immunization requirements. Adoptive parents are required to sign a waiver indicating their intention to comply with the immunization requirements within 30 days after the infant's or child's arrival in the United States.

Additional information about the medical examination and the vaccination exemption form for internationally adopted children is available on the Department of State website at http://www.travel.state.gov/family.

Follow-up Medical Examinations after Arrival in the United States

The varied geographic origins of internationally adopted infants and children, their unknown backgrounds before adoption (including parental history and living circumstances), and the inadequacy of health care in many developing countries make appropriate medical evaluation of internationally adopted children a complex and important task. This evaluation should be performed within 2 weeks of the child's arrival in the United States. The content of the medical evaluation should be guided by the unique circumstances and needs of the child, taking into account the child's region and country of birth, past living conditions, and travel and medical history. In addition to the screening for infectious disease described below, a full medical and developmental assessment should be done, with attention to possible malnutrition, conditions undetected by limited prior care, and ectoparasites such as scabies and lice, in addition to other indicated tests, such as lead or G6PD.

Screening For Infectious Diseases

Infectious diseases, among the most common medical diagnoses, have been found in up to 60% of internationally adopted children, depending on their country of origin; many of these infections can be asymptomatic (6-10). Screening for these diseases is important for the health of the adopted infant or child as well as that of their adoptive family. The American Academy of Pediatrics (AAP) recommends that all internationally adopted children be screened with the following: hepatitis B serology, HIV serology, syphilis serology, Mantoux intradermal skin test for tuberculosis, stool examination for ova and parasites, and complete blood count including a peripheral eosinophil count and red blood cell indices. Regardless of eosinophil count, all international adoptees should have three separate stool samples, collected on 3 separate days, analyzed for ova and parasites. HIV antibodies in a child younger than 18 months of age may reflect maternal infection without transmission to the infant, and infection in the infant should be confirmed with an assay for HIV DNA by polymerase chain reaction. Two negative tests obtained 1 month apart are required for the child to be considered uninfected.

Tuberculin skin tests measuring less than 5 mm are negative; reactions larger than 5 mm are interpreted based on risk factors for diseases. For internationally adopted children born in regions of the world with high TB prevalence, a reaction of 10 mm or more of induration is always positive; a reaction from 5 to 9 mm is positive if the child is immunocompromised, has been exposed to tuberculosis, or has signs or symptoms of TB disease. If the TST is positive, a chest radiograph should be performed to evaluate for active TB disease. If evidence of TB disease is found, efforts to isolate an organism for sensitivity testing are very important because of the high proportions of drug resistance in many other countries, including countries in Eastern Europe, the former Soviet Union, and Asia. Some experts also recommend that health-care providers consider repeating the TST (if negative) 2–3 months after arrival when nutritional status has been improved, particularly if the child had evidence of under-or malnutrition at the initial screening. Receipt of BCG vaccine is not a contraindication for TST. Because BCG does not prevent infection with TB and because of the high risk for exposure in most countries where BCG is given, the AAP recommends that children with a positive TST be given 9 months of iso-niazid therapy.

Up to 35% of internationally adopted children have ova or parasites identified on stool examinations (6-10). For Giardia intestinalis and Cryptosporium parvum infection, stool examination for antigen by enzyme immunoassay may be more sensitive than microscopic exam. Giardiasis is particularly prevalent in internationally adopted children from Eastern Europe. Strongyloides stercoralis serologic testing, available at CDC on request through the state public health laboratory, should be considered for children who have a high eosinophil count. If enteric symptoms develop in the future, tests should be repeated, even if it has been several years after arrival in the United States.

Other screening tests may be recommended based on country of origin, risk factors, symptoms, or clinical findings. For example, children from schistosomiasis-endemic areas should have serologic tests for schistosomiasis performed at CDC, which may be requested through the state public health laboratory (http://www.dpd.cdc.gov/dpdx/HTML/DiagnosticProcedures.htm). Screening for hepatitis C should be considered for all infants and children adopted from Asia, Eastern Europe, or Africa. Hepatitis C testing for children adopted from other areas should be considered if the records indicate potential risk factors, such as receipt of blood products or maternal drug use. Testing for hepatitis D, which is available at CDC, should be considered for children from the Mediterranean area, Africa, Eastern Europe, and Latin America who have chronic infection with hepatitis B virus.

Laboratory reports from the country of origin should not necessarily be considered reliable.

Vaccination

Internationally adopted infants and children frequently are underimmunized and should receive necessary immunizations according to the ACIP-recommended schedules in the United States. In a retrospective review of records of 504 children, the majority (65%) had no written records of overseas vaccination. Among the 178 children with documented overseas vaccination, 167 (94%) had valid records and some vaccine doses that were acceptable and up to date under the U.S. schedule. In assessing the immunization status of an internationally adopted child, only written documentation should be accepted as proof of receipt of immunization. In general, written records are deemed valid if the vaccine type, date of administration, number of doses, intervals between doses, and age of the patient at the time of administration are comparable with the current U.S. schedule. Although some vaccines with inadequate potency have been produced in other countries, most vaccines used worldwide are produced with adequate quality control standards and are reliable. However, immunization records for some internationally adopted children, particularly those from orphanages, may not reflect protection because of inaccurate or unreliable records, lack of vaccine potency, poor nutritional status, or other problems. For any child, if there is any question as to whether the immunizations were administered or were immunogenic, the best course is to repeat them. Vaccination is generally safe and avoids the need to obtain and interpret serologic tests.

In an older infant or child who is thought to have been vaccinated appropriately, judicious use of serologic testing can be helpful in determining which immunizations may be needed and can decrease the number of injections required. Children who do not have serologic evidence of previous hepatitis B infection should receive the full vaccine series. Many adopted children acquire hepatitis A virus infection early in life and are immune thereafter. Thus, in the United States it may be cost effective to screen these children for previous immunity before initiating the vaccination series. Verification of protection from MMR vaccine requires testing for antibodies to each virus. Serology is of limited availability or difficult to interpret for Haemophilus influenzae type b (Hib) and poliovirus. Vaccination for these, as well as varicella and pneumococcal disease, which are not administered in most countries, should be administered to internationally adopted children based on age and medical history.

Data indicate increased risk of local adverse reactions after the fourth and fifth doses of DTP or DTaP. In some circumstances, judicious use of serologic testing of antibody levels to assess immunity may be helpful in decreasing the possibility of vaccine side effects. For children whose records indicate that they have received more than 3 doses, options include initial serologic testing or administration of a single booster dose of DTaP, followed by serologic testing after 1 month. If a severe local reaction occurs after revaccination, serologic testing for specific IgG antibody to tetanus and diphtheria toxins can be measured before additional doses are administered. No established serologic correlates exist for protection against pertussis, but protective concentrations of antibody to both diphtheria and tetanus toxin can serve to validate the vaccination record.

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