CDC’s International Travelers’ Health Information: Special Needs Travelers
CDC’s International Travelers’ Health Information: Special Needs Travelers
CDC’s International Travelers’ Health Information: Special Needs Travelers
Editor’s note: The information below was posted on the Center for Disease Control and Prevention website (www.cdc.gov/travel) as of March 2007 and has been condensed by the editors for publication in book format. Readers should consult www.cdc.gov/travel for additional information, updates, or revisions.
By law, U.S. air carriers must comply with highly detailed regulations affecting people with disabilities, which 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) 7 am to 11 pm Eastern time to provide real-time assistance in facilitating compliance with DOT rules and to suggest possible customer-service solutions at the point of service to the airline involved (including foreign carriers). Carriers may not refuse transportation to people 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.
Internationally, the International Air Transport Association (IATA) member airlines voluntarily adhere to codes of practice that are very similar to U.S. legislation that takes provisions of the International Civil Aviation Organization into consideration. 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, such as possible communicable disease, stretcher cases, oxygen requirement, or unusual behaviors possibly affecting 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 <30 seats are generally exempt. Airline personnel are not required to transfer passengers from wheelchair to wheelchair, wheelchair 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 >60 seats needs to 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 wheel-chairs may require special separate stowage and require early arrival at the airport. Airline personnel are not obliged to assist with feeding, bodily functions, or providing medication to travelers. Internationally standardized codes for classifying disabled passengers and their needs are available in all computerized reservations systems. These 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 are not exempted from compliance with quarantine regulations and so may not be allowed to travel to all international destinations. 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.
The medical preparation of a traveler with a stable ongoing disability does not differ from that of any other traveler. The key to safe, accessible travel is that each anticipated international itinerary must be assessed on an individual basis, in consultation with specialized travel agencies or tour operators, as well as print and Internet resources with specific expertise in this area.
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 that traveler. Each proposed preventive intervention must be examined from two perspectives: 1) safety in the context of the underlying immunocompromise and ongoing medication; and 2) the possibility of decreased effectiveness of the intervention in that context. Before proceeding, the medical provider should ensure a complete understanding by the traveler of the wisdom 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 for that patient.
Severe Immunocompromise (non-HIV)
Persons considered as having severe immunosuppression include those with active leukemia or lymphoma, generalized malignancy, aplastic anemia, solid organ transplant, bone marrow transplant within 2 years of transplantation, or transplants of longer duration still on immunosuppressive drugs or with graft versus host disease, congenital immunodeficiency, and current or recent radiation therapy. For solid organ transplants, much higher risk of infection occurs within the first year of transplant, so particularly high-risk travel might be postponed until beyond that time.
Medications that cause severe immunosuppression include high-dose corticosteroids, alkylating agents (e.g., cyclophosphamide), antimetabolites (e.g., methotrexate in any dose, azathioprine, 6-mercaptopurine), transplant-related immunosuppressive drugs (e.g., cyclosporine, tacrolimus, sirolimus, and mycophenolate mofetil), mitoxantrone (used in multiple sclerosis), and most cancer chemotherapeutic agents (not tamoxifen). The immunosuppressive effects of steroid treatment vary, but most clinicians consider a dose of 20 mg/day of prednisone or equivalent administered for 2 weeks as causing severe immunocompromise.
Tumor necrosis factor (TNF)-blocking agents such as etanercept and infliximab are known to activate latent myco-bacterial infection, but the degree of overall susceptibility to other microorganisms is unclear. 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.
Severe Immunocompromise Due to Symptomatic HIV/AIDS
Consultation with the HIV-infected traveler cannot be performed without knowledge of a current CD4 lymphocyte count. HIV-infected persons with CD4 counts <200, history of an AIDS-defining illness, or clinical manifestations of symptomatic HIV are considered to have severe immuno-suppression.
Asymptomatic HIV Infection
Asymptomatic HIV-infected persons with CD4 counts from 200 to 500 are considered to have limited immune deficits. Antiretroviral drug-induced increased CD4 counts and not 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, a wait of 3 months post-reconstitution before immunization is advised by many clinicians.
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 ribavirin 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 pretravel 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 previous or underlying disease needs to be kept in mind:
- Corticosteroid therapy under the following circumstances: short-term (i.e., <2 weeks); 20 mg per day 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); intraarticular, bursal, or tendon injection of steroids; or if >1 month has passed since high-dose steroids (>20 mg/day prednisone equivalent for >2 weeks) have been used.
- HIV patients with >500 CD4 lymphocytes.
- >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 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 >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 immunosuppressive drugs (e.g., lupus, inflammatory bowel disease, rheumatoid arthritis, or multiple sclerosis). The ACIP advice for the normal use of live-virus 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 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 such as interferons and glatiramer acetate commonly used in MS patients are not thought to impact vaccine response or safety, but definitive data are lacking. In these special circumstances, travel health advisors should confer with the traveler’s other physicians in developing an appropriate plan.
Travelers with symptomatic HIV or severe non-HIV immunocompromise: 1) cannot be given live-virus or bacterial vaccines; 2) may require additional vaccines when compared with the healthy traveler; and 3) may have decreased protection from some or all vaccines administered. Go to the CDC website at CDC.gov to view a table concerning the use of vaccines for different categories of immunocompromised adults.
Overall destination and risk behavior considerations for travel-related vaccines are the same as for other travelers, although the consequences of not administering an indicated vaccine may be more severe. Sufficiently high risk for acquiring infections should prompt discussion of trip deferral or consideration of an alternate destination.
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. They should be revaccinated >3 months after therapy is discontinued with all vaccines that are still indicated at that time.
- Complete revaccination with standard childhood vaccines should begin 12 months after bone marrow transplantation. However, MMR vaccine should be administered at 24 months of age if the recipient is presumed to be immunocompetent. Influenza vaccine should be administered at 6 months of age 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. Travelers should be warned that vacci-nation waiver documents may not be accepted by some countries and that if this 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 vacci-nation and monitored closely for possible adverse effects.
As vaccine response may be suboptimal, such vaccinees are candidates for serologic testing 1 month post-vaccination. Diligent insect precautions are similarly recommended in this situation. Despite the theoretical risk for neuroinvasion and encephalitis due to vaccine, clinical or epidemiologic studies to evaluate the risk of yellow fever vaccination among severely compromised recipients have not been reported. If international travel requirements and not true exposure risk are the only reasons to vacci-nate an asymptomatic HIV-infected person or person with a limited immune deficit, a waiver letter should be given.
This vaccine is recommended or should be considered for many categories of compromised host. Normally only one dose is recommended for persons >5 years of age. This dose may be insufficient to induce immunity in immunosup-pressed persons, but the data are insufficient to recommend more than one dose.
Pneumococcal Polysaccharide Vaccine
This vaccine is recommended for many categories of compromised host, followed by a single booster at 5 years of age. Data are insufficient on the use of pneumococcal conjugate vaccine to recommend its use in compromised older children and adults.
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.
The risk for foodborne and waterborne infections among immunosuppressed persons is magnified 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. Since diarrhea is a frequent complication of highly active antiretroviral therapy for HIV, such patients should receive counseling regarding the symptoms of enteric infections.
Antimicrobial prophylaxis for travelers’ diarrhea is not recommended routinely for immunocompromised persons traveling to developing countries because of the potential for adverse effects. Nonetheless, many studies (none involving an immunocompromised population) have reported that prophylaxis can reduce the risk for travelers’ diarrhea. In circumstances in which the risk for infection is high, the period of travel brief, and the patient severely immunocompromised, the health-care provider and patient may opt for antibiotic prophylaxis with a quinolone antibiotic once a day (e.g., 500mg ciprofloxacin). Loperamide can be used to treat mild diarrhea. As for immunocompetent travelers, antimicrobial agents (e.g., fluoroquinolones or azithromycin should be provided to travelers before their departure, to be taken for self-treatment if diarrhea occurs. Severely immunocompromised travelers should have a lower threshold than other travelers for initiating self-therapy.
Meticulous malaria prevention should always be advised, as for immunocompetent travelers. Malaria does not appear to occur more frequently or pose a greater risk for adverse outcomes in immunocompromised travelers (including those with advanced HIV or asplenia), except in travelers who are both HIV infected and pregnant. 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 on nelfinavir or ritonavir is contraindicated because of potential cumulative cardiotoxicity. This drug should be used only with close monitoring in those taking amprenivir, delaviridine, or the lopinavir/ritonavir combination.
Reducing Risk for Other Diseases
Travelers should be informed about other region-specific risks and instructed in ways to reduce those risks. Geographically focal infections that pose an increased risk of severe outcome to 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 pre-existing conditions.
- 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 as in the past.
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 of an unplanned pregnancy and a need to travel. Preconceptional immunizations are preferred to vaccination of pregnant women, 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. 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. For women taking malarial prophylactic medications in anticipation of travel, no data link these medications to congenital malformations, so CDC does not recommend that women planning pregnancy need to wait a specific period of time after their use before becoming pregnant.
Pregnant women considering international travel should be advised to evaluate the potential problems associated with international travel as well as the quality of medical care available at the destination and during transit. 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. 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 her 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. 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) can be followed by pregnant women during travel. However, pregnant women should continuously use seat-belts 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 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 at any depth should be avoided in pregnancy because of the risk of decompression syndrome in the fetus.
Specific Recommendations for Pregnancy and Travel
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 can be ordered in advance. Severe anemia, sickle-cell disease or trait, or history of thrombophlebitis are relative contraindications 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 her 36th week 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 her current gestational age and expected date 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 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 >3,658 meters (>12,000 feet). In addition, altitudes >2,500 meters (>8,200 feet) should be avoided in late or high-risk pregnancy. Pregnant air travelers with medical problems that may be exacerbated by a hypoxic, high-altitude environment but who must travel by air should be prescribed supplemental oxygen during air travel. All pregnant women who have travel to high altitude should postpone exercise until acclimatized.
Food- and Waterborne Illness during Pregnancy
Pregnant travelers should be advised to exercise dietary vigilance while traveling because dehydration from travelers’ diarrhea can lead to inadequate placental blood flow and increased risk for premature labor. 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. Pregnant travelers should eat only well-cooked meats and pasteurized dairy products, while avoiding pre-prepared salads; this will help to avoid diarrheal disease as well as infections such as toxoplasmosis and Listeria, which can have serious sequelae in 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, including personal
|Half Lives of Select Antimalarial Drugs|
|Chloroquine||Can extend from 6 to 60 days|
|Mefloquine||2 to 3 weeks|
|Doxycycline||12 to 24 hours|
|Atovaquone||2 to 3 days|
|Proguanil||14 to 21 hours|
|Primaquine||4 to 7 hours|
|Sulfadoxine||150 to 200 hours|
|Pyrimethamine||80 to 95 hours|
protection to avoid infective mosquito bites and using prophylactic malaria medication as directed. 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 mefloquine 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.
Avoidance of Insects during Pregnancy
Like malaria, other vector-borne illnesses may be more severe in pregnancy, bear potential harm to the fetus, or both. Pregnant travelers should scrupulously avoid insects by wearing clothing that covers most of the body, bed nets, permethrin treatment for clothing and nets, and application of DEET-containing repellents. The recommendations for DEET use in pregnant women do not differ from those for nonpregnant adults. Women choosing lower concentrations of DEET must increase the frequency of application if staying outdoors for long periods.
Malaria must be treated as a medical emergency in any pregnant returning traveler. A woman who has traveled to an area that has chloroquine-resistant strains of P. falciparum should be treated as if she has 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.
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.
Pregnant women should be advised to avoid live-virus vaccines (measles, mumps, rubella, varicella and yellow fever). Women should also avoid becoming pregnant within 1 month of having received one of these vaccines 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. Table 9-4 summarizes use of each vaccine in pregnancy.
Routine and Travel-Related Immunizations for Pregnant Women
Ideally, all reproductive-aged women should be up to date on their routine immunizations, whether or not they are planning a pregnancy. Therefore, in the event of an unplanned pregnancy, most women would be prepared if international travel were needed. 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 routinely recommended for U.S. travelers. Skin testing for tuberculosis exposure before and after travel is preferable when the risk is high.
The combination diphtheria-tetanus immunization should be given if the pregnant traveler has not been immunized within 10 years, although preference would be for its administration during the second or third trimester.
Pregnant women without immunity to hepatitis A virus (HAV) need protection before traveling to developing countries. 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 this can occur during viremia or from fecal contamination at delivery. Immune globulin (IG) is a safe and effective means of preventing HAV, but immunization with one of the HAV vaccines gives a more complete and prolonged protection. The effect of these inactivated virus vaccines on fetal development is unknown and is expected to be low; the production methods for the vaccines are similar to that for IPV, which is considered safe during pregnancy.
The hepatitis B vaccine may be administered during pregnancy and is recommended for pregnant women at risk for hepatitis B virus infection. Exposed newborns need to be vaccinated and receive immune globulin as soon as possible.
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.
Because of the increased risk for influenza-related complications, women who will be beyond the first trimester of pregnancy (>14 weeks gestation) during the influenza season of their travel destination should be vaccinated, when vaccine is available. Further, those with chronic diseases that increase their risk of influenza-related complications should be vaccinated, regardless of gestational dates. Data from influenza immunization of >2,000 pregnant women have not demonstrated an association with adverse fetal effects.
No information is available on the safety of Japanese encephalitis vaccine during pregnancy. It should not be routinely administered during pregnancy, except when a woman must stay in a high-risk area. If not mandatory, travel to such areas should be postponed until after delivery and until the infant is old enough to be safely vaccinated (1 year).
Measles, Mumps, and Rubella
The measles vaccine, as well as the measles, mumps, and rubella (MMR) vaccines in combination, are live-virus vaccines and so they are contraindicated in pregnancy. However, in cases in which the rubella vaccine was unintentionally administered, no complications have been reported. Because of the increased incidence of measles in children in developing countries and because of the disease’s communicability and its 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.
The polyvalent meningococcal meningitis vaccine 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 meningococcal vaccines administered during pregnancy, altering meningococcal vaccination recommendations during pregnancy is unnecessary.
The safety of pneumococcal polysaccharide vaccine during the first trimester of pregnancy has not been evaluated, although no adverse fetal consequences have been
|Vaccination During Pregnancy|
|Hepatitis A||Inactivated virus||Data on safety in pregnancy are not available; the theoretical risk of vaccination should be weighed against the risk of disease. Consider immune globulin rather than vaccine.|
|Hepatitis B||Recombinant or plasma-derived||Recommended for women at risk of infection.|
|Immune globulins, pooled or hyperimmune||Immune globulin or specific globulin preparations||If indicated for pre- or post-exposure use. No known risk to fetus.|
|Influenza||Inactivated whole virus or subunit||All women who are pregnant in the second and third trimesters during the flu season; women at high risk for pulmonary complications, regardless of trimester.|
|Japanese encephalitis||Inactivated virus||Data on safety in pregnancy are not available; the theoretical risk of vaccination should be weighed against the risk of disease.|
|Measles||Live attenuated virus||Contraindicated; vaccination of susceptible women should be part of postpartum care.|
|Meningococcal meningitis||Polysaccharide||Indications for prophylaxis not altered by pregnancy; vaccine recommended in unusual outbreak situations.|
|Mumps||Live attenuated virus||Contraindicated; vaccination of susceptible women should be part of postpartum care.|
|Pneumococcal||Polysaccharide||Indications not altered by pregnancy.|
|Polio, inactivated||Inactivated virus||Indicated for susceptible pregnant women traveling in endemic areas or in other high-risk situations.|
|Rabies||Inactivated virus||Indications for prophylaxis not altered by pregnancy; each case considered individually.|
|Rubella||Live attenuated virus||Contraindicated; vaccination of susceptible women should be part of postpartum care.|
|Diphtheria-Tetanus||Toxoid||If indicated, such as lack of primary series, or no booster within past 10 years.|
|Typhoid (ViCPS)||Polysaccharide||If indicated for travel to endemic areas.|
|Typhoid (Ty21a)||Live bacterial||Data on safety in pregnancy are not available.|
|Tuberculosis (BCG)||Attenuated mycobacterial||Contraindicated.|
|Varicella||Live attenuated virus||Contraindicated; vaccination of susceptible women should be considered postpartum.|
|Yellow fever||Live attenuated virus||Indicated if exposure cannot be avoided. Postponement of travel preferable to vaccination, if possible.|
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.
The pregnant traveler must be protected against poliomyelitis. 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. 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. There is no convincing evidence of adverse effects of inactivated poliovirus vaccine in pregnant women or developing fetuses. However, it is prudent to avoid polio vaccination of pregnant women unless immediate protection is needed.
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.
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. With either of these, the vaccine efficacy (about 70%) needs to be weighed against the risk of disease.
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 overseas.
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 can 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. Although concerns exist, no congenital abnormalities have been reported after administration of this vaccine to pregnant women. 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.
In general, pregnant women should be advised to postpone travel to areas where yellow fever is a risk until after delivery, when vaccine can be administered to the mother without concern of fetal toxicity. Travelers with infants <9 months of age should be strongly advised against traveling to areas within the yellow fever-endemic zone.
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, ORS 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 proteinuria and glucosuria, both of which would require prompt medical attention. Antimalarial and antidiarrheal self-treatment medications should be evaluated individually, depending on the traveler, her gestational age, itinerary, and her health history. Most medications should be avoided, if possible.
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 bottle-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.
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 (www.lalecheleague.org).
A mother traveling with a nursing infant <6 months old need not plan on supplementing breastfeeding because of international travel. Breastfed infants do not require water supplementation, even in extreme heat environments, if the mother is adequately hydrated. A breastfeeding mother traveling without her nursing infant or child may wish to build a supply of milk to be fed to the infant or child during her absence by expressing milk and storing it for later use by another caregiver.
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 expression.
The destination for travel can impact decisions for milk storage. Once milk is cooled, a cold chain needs to be maintained until milk is consumed. Refrigerated milk can subsequently be frozen; however, once frozen milk is fully thawed, it should be used within 1 hour. See the CDC website at CDC.gov for more information on proper milk storage.
Most nursing mothers may be immunized routinely, based on recommendations for the specific travel itinerary. Breastfeeding is not a contraindication to the administration of vaccines, including live-virus vaccines; however, there is a theoretical risk to the infant with the use of the yellow fever vaccine in breastfeeding mothers. Breastfed infants should be vaccinated according to routine recommended schedules.
Breastfeeding mothers should take the usual adult dose of the antimalarial drug appropriate for the itinerary. Nursing mothers with infants weighing <11 kg (approximately 24 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
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.
No special precautions are necessary for airport security screenings while breastfeeding. Breast milk does not need to be declared at US Customs when returning to the United States. Electric breast pumps are 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.
Breastfed infants are protected from travelers’ diarrhea, and thus it is often recommended that a nursing mother try, if reasonable, to continue to breastfeed until returning home. 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. 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.
Note: Updated immunization schedule (January 12, 2006)
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 childhood vaccinations because many of the diseases prevented by these vaccines are rare or nonexistent in the United States but are still common in other parts of the world. The recommended childhood and adolescent immunization schedule is depicted in Table 8-2. Table 8-3 depicts the catch-up schedule for children and adolescents who start their vaccination schedule late or who are >1 month behind. This table also describes the recommended minimal intervals between doses for children who need to be vaccinated on an accelerated schedule, which is sometimes required for international travel. 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.
Modifying the Immunization Schedule for Inadequately Immunized Infants and Younger Children before International Travel
Factors influencing recommendations for the age at which a vaccine is administered include the age-specific risks of the disease and its complications, the ability of people of a given age to respond to the vaccine, and the 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 infants and young children who will travel 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 routine immunizations recommended in the United States (except for the dose of hepatitis B vaccine administered at birth) is at 6 weeks if an accelerated schedule is followed. Parents should also be aware of the youngest age at which vaccinations can be administered for diseases endemic at their destination. The following section provides additional guidance for active and passive immunization of such infants and children.
Routine Infant and Childhood Vaccinations
Hepatitis B Vaccine
Hepatitis B virus is a cause of acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. There are 200 to 300 million chronic carriers worldwide. Infants and children who have not previously been vaccinated and who are traveling to areas with intermediate and high hepatitis B virus (HBV) endemicity are at risk if they are directly exposed to 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, with the first dose administered soon after birth and before hospital discharge. 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 1-2 months. Between doses two and three, the interval should be a minimum of 2 months; the interval between doses one and three should be at least 4 months. The third dose should not be given before the infant is 6 months 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 in the first year of life is achieved with at least three but preferably four doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), the first administered when the infant is 6-8 weeks of age and the next two at 4- to 8-week intervals. A fourth dose of DTaP should be administered 6-12 months after the third dose when the infant is 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.
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. For infants and children <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.
Haemophilus influenzae Type b Conjugate Vaccine
Haemophilus influenzae type b (Hib) is an endemic disease worldwide that can cause fatal cases of 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. Hib vaccine should never be given to an infant <6 weeks of age. A primary series consists of two or three doses (depending on the type of vaccine used) separated by 4-8 weeks. A booster dose is recommended when the infant is 12-15 months of age.
If Hib vaccination is started when the infant or child is 7 months of age, fewer doses may be 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 <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 >59 months of age do not need to be vaccinated unless a specific condition exists such as functional or anatomic asplenia, immunodeficiency, immunosuppression, or HIV infection.
While polio has been eradicated in the United States, poliovirus continues to circulate in parts of Africa and Asia. In the United States, all infants and children should receive four doses of inactivated poliovirus vaccine (IPV) at 2, 4, and 6-18 months and 4-6 years of age. If accelerated protection is needed, the minimum interval between doses is 4 weeks, although the preferred interval between the second and third doses is 2 months. 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.
Measles, Mumps, and Rubella Vaccine
Measles is an endemic disease in countries where measles immunization levels are low, and the risk for contracting measles in many countries is greater than in the United States. 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. However, the Advisory Committee on Immunization Practices (ACIP) recommends that MMR be administered when any of the individual components is indicated.
According to the recommended childhood immunization schedule (Table 8-2), a child should receive MMR at age 12 months and again at age 4-6 years. For children who are 12 months of age, the second dose of MMR may be given 28 days after the first dose.
Infants 6-11 months of age should receive a dose of MMR before departure. 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 age 12 months.
If MMR is unavailable, monovalent vaccines may be used. However, a child receiving monovalent vaccines will still need two doses of MMR beginning at age 12 months.
Varicella (chickenpox) is an endemic disease throughout the world. The varicella vaccine is recommended for all children 12 months of age.
A single dose of varicella vaccine is also recommended for all susceptible children by their 13th birthday. Efforts should be made to ensure varicella immunity by this age, because varicella disease can be more severe among older children and adults. Children >13 years of age need to receive two doses of varicella vaccine at least 4 weeks apart to optimize protection.
Vaccination is not necessary for children with a reliable history of chickenpox. When a prior history of chickenpox is unclear, the vaccine may be given.
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 vacci-nation provides the earliest protection and infants <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 at high risk for the development of pneumococcal disease (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, 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 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. Previously unvaccinated healthy children 24-59 months of age should receive a single dose of PCV7. However, previously unvaccinated children 24-59 months of age at high risk for pneumococcal disease should receive two doses separated by at least 8 weeks. Children 24-59 months of age who are at increased risk for pneumococcal disease (as previously described) 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 >59 months (5 years) of age.
Influenza vaccine can be used to reduce risk of influenza infection in transmission season (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 6-23 months of age should receive TIV annually. In addition, all children with risk factors for influenza (including but not limited to asthma, cardiac disease, sickle cell disease, HIV, and diabetes) should also receive TIV annually. In addition, all children who have close contact with healthy children <24 months of age or with persons at high risk should be vaccinated annually. For healthy children 5 years of age, 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). Children 8 years of age who are receiving influenza vaccine for the first time should receive two doses (separated by at least 4 weeks for TIV and at least 6 weeks for LAIV). Children 9 years of age 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 <5 years of age, those infected efficiently transmit infection to other infants and children and to adults.
Children 2 years of age who will be traveling to areas where there is a high risk of HAV infection should be immunized. 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 <2 years of age. Children <2 years of age and children who will be traveling less than 4 weeks after receipt of the first dose should be administered immune globulin (IG). The vaccine and IG can be administered at the same time at different anatomic sites.
IG interferes with the response to live injected vaccines (e.g., measles, mumps, rubella, and varicella vaccines). Administration of live vaccines should be delayed for at least 3 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 and Immune Globulin
Yellow Fever Vaccine
Yellow fever, a disease transmitted by mosquitoes, is endemic in certain areas of Africa and South America (Maps 4-12 and 4-13). 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-vacci-nation encephalitis were in infants <4 months old. One fatal case confirmed by viral isolation was in a 3-year-old child.
Travelers with infants <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 <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 >9 months of age can be vaccinated if they travel to countries within the yellow fever-endemic zone. Physicians considering vaccinating infants <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 fever is an acute, life-threatening febrile illness caused by the bacterium Salmonella enterica Typhi.
Two typhoid vaccines are available: a Vi capsular polysaccharide vaccine (ViCPS) administered intramuscularly and an oral, live, attenuated vaccine (Ty21a). Both vaccines cines induce a protective response in 50%-80% of recipients. The ViCPS vaccine can be administered to children 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. All the capsules should be taken at least 1 week before potential exposure. A booster series for Ty21a can be taken every 5 years.
Because neither vaccine is fully protective, preventing contamination of food and beverages remains extremely important.
Meningitis primarily affects children and adolescents, with high morbidity and mortality rates. Epidemics are recurrent in sub-Saharan Africa during the dry season (December through June), and CDC recommends travelers be vaccinated before traveling to this region during the dry season. Meningococcal vaccination is a requirement to enter Saudi Arabia when traveling to Mecca during the annual Hajj.
One meningococcal vaccine is licensed for use in the United States: the quadrivalent A, C, Y, and W-135 vaccine. The serogroup A polysaccharide in this vaccine 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 <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, revaccination should be considered in 3-5 years if they remain at high risk.
Japanese Encephalitis Vaccine
Primarily night-biting mosquitoes in rural areas of Asia and the Pacific Rim transmit Japanese encephalitis (JE). 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, the mortality rate can be as high as 30%, and neurologic sequelae are reported in 50% of survivors. Serious neurologic sequelae occur more frequently 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. Travelers with extensive unprotected outdoor, evening, and nighttime exposure in rural areas, such as might be experienced while bicycling, camping, or engaging in certain occupational activities, might be at high risk even if their trip is brief. 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 receive 1.0 mL of vaccine per dose. No data are available on vaccine efficacy for infants <1 year of age. JE vaccine is associated with local reactions and mild systemic side effects (fever, headache, myalgias, and malaise). Serious allergic reactions, including anaphylaxis, have occurred up to 1 week after immunization. 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 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. Children should always be instructed to avoid contact with unfamiliar animals because those animals could be infected with rabies.
Three 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 days. Even if a child has completed the pre-exposure prophylaxis, any mammal bite warrants immediate medical evaluation to determine the need for postexposure immunization.
Approximately 20,000 infants and children are adopted from abroad each year by citizens of the United States. Infants and children from Asia, Central and South America, and Eastern Europe account for >90% of international adoptions. To complete an international adoption and bring an infant or a child to the United States, prospective parents must fulfill the requirements set by the Bureau of Citizenship and Immigration Services (BCIS) http://uscis.gov/graphics/index.htm (formerly the Immigration and Naturalization Service [INS]), the foreign country where the infant or child resides, and sometimes the state of residence of the adoptive parent(s). The adoption of a foreign-born orphan does not automatically guarantee the child’s eligibility to immigrate to the United States. The adoptive parent needs to be aware of U.S. immigration law and legal regulatory procedures. An orphan cannot legally immigrate to the United States without BCIS processing.
An infant or child cannot be brought to the United States without an immigrant visa, issuance of which is based on a BCIS-approved petition. Detailed information about the procedures and requirements for international adoptions is available on the BCIS website at http://www.bcis.gov/graphics/services/index2.htm. When the Orphan Petition has been approved by the BCIS, the adoptive parent(s) can apply for an immigrant visa (IR-3) at the appropriate U.S. consular office abroad. In addition to the approved Orphan Petition, the consular officer will also require specific documentation, including a medical examination of the nadoptee.
Adoptive parents who travel overseas to pick up their child should obtain pre-travel advice. They should be aware that unexpected complications in the adoption process may prolong their stay and should plan accordingly, especially if malaria prophylaxis or other important medication is needed. In addition, 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. Recently, an outbreak of measles was identified among children being adopted from China and their family members. Therefore, all traveling family members should be sure that they are up to date on recommended vaccinations, including MMR, prior to travel.
Overseas Medical Examinations
All immigrants, including infants and children adopted overseas by U.S. citizens, and refugees coming to the United States must have a medical examination overseas by a designated physician. 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 BCIS. 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. Applicants <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 the Advisory Committee on Immunization Practices (ACIP) before immigration. While this new subsection now applies to all immigrant infants and children entering the United States, internationally adopted children <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 are available on the Department of State website at http://www.travel.state.gov/adopt.html.
Follow-Up Medical Examination 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. An internationally adopted infant or child should be examined within 2 weeks of his or her arrival in the United States, but an adoptee who has an acute illness or a chronic condition needs immediate attention. All adopted infants and children should have a complete physical examination, a review of any available medical records, and age-appropriate screening tests, including evaluation for possible anemia, vision and hearing impairments, and assessment of growth and development. Children >18 months of age should also have a dental evaluation.
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. 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 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 with red blood cell indices. Other screening tests may be recommended based on country of origin, risk factors, symptoms, or clinical findings. Laboratory reports from the country of origin should not be considered reliable.
Routine serologic screening for hepatitis A infection is not indicated. Many adopted children acquire hepatitis A virus infection early in life and are immune thereafter. However, for adopted children who will be residing in an area of the United States where routine hepatitis A vaccination is recommended, it may be cost effective to screen these children for previous immunity before initiating the vaccination series. All internationally adopted children should be screened for hepatitis B infection, including hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc). If a child is hepatitis B surface antigen (HBsAg) positive, all unvaccinated household contacts should receive the full vaccine series. Children who test positive for HBsAg should receive a medical evaluation for chronic hepatitis B infection. Children who do not have serologic evidence of previous infection should receive the full vaccine series. 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.
Risk of HIV depends on country of origin and individual risk factors. However, because of the rapidly changing global epidemiology of HIV and often unknown backgrounds, screening for antibodies to HIV should be considered for all internationally adopted children. If test results are available from the adopted child’s country of origin, repeat testing should be performed to confirm the overseas results. Antibodies in a child <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.
Regardless of overseas testing results and/or history of treatment, internationally adopted children should be tested for syphilis by nontreponemal and treponemal sero-logic tests upon arrival. Children who have positive tests should receive further evaluation for treatment.
Mantoux tuberculin skin testing (TST) is recommended for international adoptees because their rates of TB infection are several times higher than those of U.S.-born children. The definition of a positive TST for children born in regions of the world with high TB prevalence is 10 mm of induration. If the TST is positive, a chest radiograph must 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. Receipt of BCG vaccine is not a contraindication for TST. After BCG immunization, however, distinguishing between a positive TST result caused by M. tuberculosis infection and that caused by BCG can be difficult. However, infection with M. tuberculosis should be strongly suspected in any asymptomatic child with a positive TST result, regardless of history of BCG immunization. Circumstances that increase the likelihood that a positive TST is due to TB infection include contact with a person with active TB, immigration from a country with high TB prevalence, or a long interval since the last BCG immunization. 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 isoniazid therapy.
Parasites and Intestinal Pathogens
Up to 35% of internationally adopted children have ova or parasites identified on stool examinations. Internationally adopted children should have a complete blood count with a peripheral eosinophil count, which may be an indicator of parasitic disease infection. Regardless of the eosinophil count, all internationally adopted children should be screened initially with three separate stool samples, collected on 3 separate days, analyzed for ova and parasites. If enteric symptoms develop in the future, these tests should be repeated, even if it has been several years after arrival in the United States. 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. Children from schistosomiasis-endemic areas should have serologic tests for schistosomiasis performed at CDC. These tests may be requested through the state public health laboratory.
Children with diarrhea should also be evaluated for bacterial organisms, including Escherichia coli species, Salmonella species, Shigella species, and Campylobacter species.
Internationally adopted children should be carefully examined for scabies and lice, so that they can be appropriately treated and to prevent infestation of family members and contacts.
Evaluation for Other Medical Problems
Potentially dangerous levels of lead have been reported in internationally adopted children, particularly those from China, Cambodia, Russia, and other countries in Eastern Europe. Lead exposure in other countries can result from a variety of sources, including leaded gasoline exhaust, ceramic ware, and traditional medicines. All children from these areas of the world and any others in whom lead toxicity is suspected should be screened, with follow-up and treatment based on standard guidelines. Information about lead poisoning is available at www.cdc.gov/nceh/lead/lead.htm or by calling 1-800-232-6789.
This enzyme deficiency is relatively common in persons from Asia, the Mediterranean area, and Africa. Screening for this deficiency in children from these areas should be considered before drugs are prescribed that can cause hemolysis in persons who have G6PD deficiency.
Internationally adopted children <11 years of age are not required to have vaccinations before arrival in the United States as long as the adoptive family signs a waiver stating that they will have the child vaccinated within 30 days of arrival in the United States. Internationally adopted infants and children frequently are underimmunized and should receive necessary immunizations according to recommended schedules in the United States. In a retrospective review of records of 504 children, 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. 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 >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.
In the United States, multiple outbreaks of measles have been reported in children who were recently adopted from China and in their U.S. contacts. Measles outbreaks among children in Chinese orphanages were also reported. 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. 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. All persons born after 1957 should receive two doses of measles-containing vaccine.