CDC's International Traveler's Health Information Special Needs Travelers
CDC's International Traveler's Health Information
Special Needs Travelers
Editor's note: The information below was posted on the State Department's website (www.state.gov) as of March 2004 by Bureau of Consular Affairs and has been condensed by the editors for publication in book format. Readers should consult www.state.gov for additional information, updates, or revisions.
INTERNATIONAL TRAVELERS WITH DISABILITIES
Date last revised: July 17, 2003
PREGNANCY, BREAST-FEEDING, AND TRAVEL
Date last revised: July 17, 2003
Date last revised: July 17, 2003
GENERAL INFORMATION REGARDING HIV AND TRAVEL
Date last revised: July 17, 2003
U.S. air carriers must comply with the U.S. laws and regulations regarding access for travelers with disabilities. Foreign airlines have varying regulations for access, which must be as certained in detail from the carrier in advance of travel. 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. Extra services and accommodations for disabled travelers, often protected by legislation, are generally available in North America, Western Europe, and Australia and New Zealand, but very irregularly elsewhere. 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. Listings and links to appropriate resources, professionals as well as destination-specific information, can be found at www.accessable.com.
Factors Affecting the Decision To Travel
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 experiencing a 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 preventative and treatment measures. Table 6–1 lists relative contraindications to international travel during pregnancy. In general, pregnant women with serious underlying illnesses should be advised not to travel to developing countries.
Preparation for Travel
Once a pregnant woman has decided to travel, a number of issues need to be considered before her departure.
Ensure that her health insurance is valid while abroad and during pregnancy, and that the policy covers a newborn should delivery take place. 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 her destination. The pregnant traveler and her companion(s) should also be advised to know their blood types.
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.
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 blunt, mild trauma, a physician should be consulted.
Hepatitis E (HEV), 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.
Obstetrical risk factors:
- History of miscarriage
- Incompetent cervix
- History of ectopic pregnancy (ectopic with current pregnancy should be ruled out before travel)
- History of premature labor or premature rupture of membranes
- History of or existing placental abnormalities
- Threatened abortion or vaginal bleeding during current pregnancy
- Multiple gestation in current pregnancy
- Fetal growth abnormalities
- History of toxemia, hypertension, or diabetes with any pregnancy
- Primigravida at 35 years of age and older, or 15 years of age and younger
General Medical Risk Factors:
- History of thromboembolic disease
- Pulmonary hypertension
- Severe asthma or other chronic lung disease
- Valvular heart disease (if NYHA class III or IV heart failure)
- Renal insufficiency
- Severe anemia or hemoglobinopathy
- Chronic organ system dysfunction requiring frequent medical interventions
Risk Factors in Travel to Potentially Hazardous Destinations:
- High altitudes
- Areas endemic for or with ongoing outbreaks of life-threatening food- or insect-borne infections
- Areas where chloroquine-resistant Plasmodium falciparum malaria is endemic
- Areas where live virus vaccines are required and recommended
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 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 expected date of delivery.
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.
Travel to High Altitudes during Pregnancy
Acclimatization responses at altitude act to preserve fetal oxygen supply, but all pregnant women traveling to high altitude should avoid altitudes > 4,000 meters (13,123 feet) In addition, altitudes >2,500 meters (8,200 feet) should be avoided in late or high-risk pregnancy. All pregnant women who have recently traveled to a higher altitude should postpone exercise until acclimatized.
Breast-Feeding and Travel
The decision to travel internationally with a nursing infant produces its own challenges. However, breast-feeding has nutritional and anti-infective advantages that serve an infant well while traveling. Moreover, exclusive breast-feeding relieves concerns about sterilizing bottles and availability of clean water. Supplements are usually not needed by breast-fed infants <6 months of age, and breast-feeding should be maintained as long as possible. If supplementation is considered necessary, powdered formula that requires reconstitution with boiled water should be carried. For short trips, it may be feasible to carry an adequate supply of pre-prepared canned formula.
Nursing women may be immunized routinely, based on recommendations for the specific travel itinerary. However, consideration needs to be given to the neonate who cannot be immunized at birth and who would not gain protection against many infections (e.g., yellow fever, measles, and meningococcal meningitis) through breast-feeding. Neither inactivated nor live virus vaccines affect the safety of breast-feeding for mothers or infants. Breast-feeding does not adversely affect immunization and is not a contraindication to the administration of any vaccines, including live virus vaccines. Although rubella vaccine virus may be transmitted in breast milk, the virus usually does not infect the infant and, if it does, the infection is well tolerated. Whether attenuated vaccine VZV is excreted in human milk and, if so, whether the infant could be infected are not known. Breast-fed infants should be vaccinated according to routine recommended schedules.
Nursing women should be advised that disruptions of eating and sleeping patterns, as well as other stressors, may affect their milk output. They need to increase their fluid intake, avoid excess alcohol and caffeine, and, as much as possible, avoid exposure to tobacco smoke.
A nursing mother with travelers' diarrhea should not stop breast-feeding, but should increase her fluid intake. Breast-feeding is desirable during travel and should be continued as long as possible because of its safety and the resulting lower incidence of infant diarrhea.
Women traveling with neonates or infants should be advised to check with their pediatricians regarding any medical contraindications to flying. Infants are particularly susceptible to pain with eustachian tube collapse during pressure changes. Breast-feeding during ascent and descent relieves this discomfort.
Food- and Waterborne Illness during Pregnancy and Breast-Feeding
Pregnant travelers should be advised to exercise dietary vigilance while traveling during pregnancy because dehydration from travelers' diarrhea can lead to inadequate placental blood flow and increased risk for premature labor. 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. Pregnant women should be advised not to use prophylactic antibiotics for the prevention of travelers' diarrhea.
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, but loperamide should be used only when necessary. The antibiotic treatment of travelers' diarrhea during pregnancy can be complicated. An oral third-generation cephalosporin may be the best option 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 malarious areas if possible. Women who do choose to go to malarious countries can reduce their risk of acquiring malaria by following several preventive approaches, including personal 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; 2) if outdoors at night,
|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|
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. (See also "Protection against Mosquitoes and Other Arthropods".) Pyrethrum-containing house sprays or coils may also be used indoors if insects are a problem. Nursing mothers should be advised to carefully wash repellents off their hands and breast skin before holding and nursing their infants. 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. (Also see section "Chemoprophylaxis during Pregnancy".)
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, Table 6–2 provides information on the half-lives of selected antimalarial drugs. After 2, 4, and 6 half-lives, approximately 25%, 6%, and 2% of the drug remains in the body.
Nursing mothers should be advised to take the usual adult dose of antimalarial appropriate for the country to be visited. The amount of medication in breast milk will not protect the infant from malaria. Therefore, the breast-feeding child needs his or her own prophylaxis. (Also see section "Antimalarial Drugs during Breast-feeding.)
Avoidance of Insects during Pregnancy
Like malaria, other vector-borne illnesses may be more severe in pregnancy and/or bear potential harm to the fetus. Pregnant travelers should scrupulously avoid insects with covering clothing, bed nets, use of permethrin 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 often if staying outdoors for long periods.
Any pregnant returning traveler with malaria needs to have the illness treated as a medical emergency. 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 determination 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. 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 accidental administration of these vaccines during pregnancy. Table 6–3 summarizes use of each vaccine in pregnancy.
Ideally, all women who are pregnant should be up to date on their routine immunizations. Pregnant travelers may visit areas of the world where diseases eliminated by routine vaccination in the United States are still endemic.
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.
The hepatitis B vaccine may be administered during pregnancy and is recommended for pregnant women at risk for Hepatitis B virus infection.
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. 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 over 2,000 pregnant women has not demonstrated an association with adverse fetal effects.
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 accidentally 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, nonimmune women should delay traveling until after delivery, when immunization can be given safely. If a pregnant woman has a documented exposure to measles, immune globulin should be given within a 6-day period to prevent illness.
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 or pulmonary problems should consider vaccination.
It is important for the pregnant traveler to be protected against poliomy elitis. 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.
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.
Travel-Related Immunization during Pregnancy
Immune Globulin Preparations
No known fetal risk exists from passive immunization of pregnant women with immunoglobul in preparations. Administration of immune globulin can be used pre-exposure as protection against Hepatitis A or for postexposure management for other viral diseases if warranted.
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 during pregnancy. Skin testing for tuberculosis exposure before and after travel is preferable when the risk is high.
|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 postexposure use. No known risk to fetus.|
|Influenza||Inactivated whole virus or subunit||Recommended for pregnant women who will be in an area during influenza season after first 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|
|Meningococcal meningitis||Polysaccharide||If indicated|
|Mumps||Live attenuated virus||Contraindicated|
|Polio, inactivated||Inactivated virus||If indicated|
|Rabies||Inactivated virus||If indicated|
|Rubella||Live attenuated virus||Contraindicated|
|Typhoid (ViCPS)||Polysaccharide||If indicated|
|Typhoid (Ty21a)||Live bacterial||Data on safety in pregnancy are not available.|
|Tuberculosis (BCG)||Attenuated mycobacterial||Contraindicated|
|Varicella||Live attenuated virus||Contraindicated|
|Yellow fever||Live attenuated virus||Indicated if exposure cannot be avoided.|
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 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.
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).
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.
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.
There are no data 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.
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 9 months after delivery, when vaccine can be administered to the mother without concern of fetal toxicity and when there is low risk of vaccine-associated encephalitis for the infant.
The Travel Health Kit during Pregnancy
Additions and substitutions to the usual travel health kit need to be made during pregnancy and nursing. Talcum powder, a thermometer, oral rehydration salt (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 attention. Antimalarial and antidiarrheal self-treatment medications should be evaluated individually, depending on the traveler, her trimester, the itinerary, and her health history. Most medications should be avoided, if possible.
Vaccine Recommendations for Infants and Children
Date last revised: July 17, 2003
Each traveler needs to be fully up to date with routine childhood vaccinations because diseases covered by these vaccines that are now rare or nonexistent in the United States are still common in other areas of the world. The recommended childhood and adolescent immunization schedule is depicted in Table 7–1. Table 7–2 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. Vaccination against yellow fever is required for travel to some countries (see Yellow Fever Vaccine Requirements and Information on Malaria Risk and Prophylaxis, by Country). Recommendations for other vaccines and immunobiologics depend on the area of travel and health status of traveler and include Hepatitis A vaccine or immune globulin and vaccinations for typhoid, meningitis, Japanese encephalitis, rabies, and influenza. Administration of these vaccines should not interfere with or postpone administration of any of the recommended childhood immunizations. If necessary, some portions of the vaccine schedule can be accelerated so that as many vaccines as possible can be given before departure. In children with chronic illnesses, decisions regarding vaccinations should be made in cooperation with their personal physicians.
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. The following section provides additional guidance for active and passive immunization of such infants and children. Additional information about all the diseases and vaccines mentioned below can be found in Chapter 3 (Specific Recommendations for Vaccinations and Disease Prevention).
Routine Infant and Childhood Vaccine-Preventable Diseases
Diphtheria and Tetanus Toxoid and Pertussis Vaccine
Diphtheria is an endemic disease in many low-income countries and has been found in the independent countries of the former Soviet Union. Tetanus occurs worldwide.
Pertussis is common in resource-poor countries and in other areas where pertussis immunization levels are low. Infants and children leaving the United States should be as well immunized as possible. Optimum protection against diphtheria, tetanus, and pertussis in the first year of life is achieved with three 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 from 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.
Measles is an endemic disease in many low-income countries and in other countries where measles immunization levels are low. Because the risk of contracting measles in many countries is greater than in the United States, infants and children should be as well protected as possible before traveling. Infants and children who travel or live abroad should be vaccinated at an earlier age than is recommended for infants and children who remain in the United States. Before their departure from the United States, infants and children of 12 months of age or older should have received two doses of MMR vaccine separated by at least 28 days, with the first dose administered on or after the first birthday. Infants 6–11 months of age should receive a dose of monovalent measles vaccine before departure. If monovalent measles vaccine is not available, no specific contraindication exists to administering MMR to infants 6–11 months of age. However, because the risk for serious disease from either mumps or rubella infection among infants is relatively low and because infants <12 months of age are less likely to develop serologic evidence of immunity when vaccinated with MMR antigens than are older infants and children, mumps and rubella vaccines generally are administered only to infants and children 12 months of age or older. Infants administered monovalent measles vaccine or MMR before their first birthday should be considered potentially susceptible to all three diseases and should be revaccinated with two doses of MMR, the first of which should be administered when the infant is 12–15 months of age (12 months if the infant remains in an area where disease risk is high) and the second at least 28 days later.
Parents who travel or live abroad with infants <12 months of age should have acceptable evidence of immunity to rubella and mumps, as well as measles, so they will not become infected if their infants contract these diseases. An infant <6 months of age is usually protected against measles, mumps, and rubella by maternally derived antibodies and ordinarily does not need additional protection unless the mother is diagnosed with measles.
Mumps and Rubella Vaccine(s)
Because the risk of serious disease from infection with either mumps or rubella in infants is low, mumps and rubella vaccine(s) generally should not be administered to infants <12 months of age unless measles vaccine is indicated and single-antigen measles vaccine is not available. However, parents of an infant <12 months of age should be immune to mumps and rubella so they will not expose the infant or become infected if the infant becomes ill.
Varicella (chickenpox) is an endemic disease throughout the world. A single dose of varicella vaccine should be administered to all susceptible infants and children without contraindications at 12 months of age or older. Infants and children who have a reliable history of having had chickenpox do not need to be vaccinated. Infants <12 months of age are generally protected from varicella because of passive maternal antibody.
Because OPV is no longer used for routine immunization in the United States, all infants and children should receive four doses of IPV at 2, 4, and 6–18 months and 4–6 years of age. If accelerated protection is needed, the minimum interval between doses should be 4 weeks, although the preferred interval between the second and third doses is 2 months. Infants and children who have initiated the poliovirus vaccination series with one or more doses of OPV should receive IPV to complete the series.
Haemophilus influenzae Type b Conjugate Vaccine
Haemophilus influenzae type b (Hib) is an endemic disease worldwide. Risk of acquiring the disease might be higher in resource-poor countries than in the United States. In the United States, three types of Hib conjugate vaccines are available. One Hib conjugate vaccine for infants is also available as a combined DTaP-Hib vaccine. 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 or older, 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.
Infants and children should have optimal protection before traveling. If previously unvaccinated, infants <15 months of age should ideally 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.
Hepatitis B Vaccine
Hepatitis B vaccine is recommended for all infants, with the first dose administered in the first 2 months of life, preferably at birth. Infants and young 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 include receipt of blood transfusions not screened for HBV surface antigen (HBsAg), exposure to unsterilized needles (or other medical or dental equipment) in local health facilities, or continuous close contact with local residents who have open skin lesions (impetigo, scabies, or scratched insect bites). Such exposures are most likely to occur if an infant or a child is living for long periods in smaller cities or rural areas and in close contact with the local population.
Infants and children who will live in an area of intermediate or high HBV endemicity for 6 months or more and who are expected to have the preceding exposures should receive the three doses of HBV vaccine. 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.
Other Vaccines and Immune Globulin
Typhoid vaccination is not required for international travel. No data are available concerning the efficacy of typhoid vaccine in infants. Breast-feeding is likely to be protective against typhoid; careful preparation of formula and food from safe water and foodstuffs should protect infants who are not breast-fed. Typhoid vaccine is recommended for children 2 or more years of age traveling to areas where there is a recognized risk of exposure to Salmonella Typhi, particularly if they are traveling to highly disease-endemic areas.
Yellow Fever Vaccine
Because infants are at high risk for developing encephalitis from yellow fever 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 postvaccination encephalitis were in infants <4 months old. One fatal case confirmed by viral isolation was in a 3-year-old child. The ACIP recommends that yellow fever vaccine never be given to infants <6 months of age. Yellow fever vaccine can be given to infants and children >9 months of age if they are traveling to or living in areas of South America and Africa where yellow fever infection is officially reported (see Summary of Health Information for International Travel, also known as the "Blue Sheet") or to countries that require yellow fever immunization (see Chapter 2: Yellow Fever Vaccine Requirements and Information on Malaria Risk and Prophylaxis, by Country). Infants and children >9 months of age should be immunized if they travel to countries within the yellow fever endemic zone (see Chapter 2, Yellow Fever Vaccine Requirements and Information on Malaria Risk and Prophylaxis, by Country, and Maps 3–9 and 3–10). Travelers with infants <9 months of age should be strongly advised against traveling to areas with epidemic yellow fever. 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. Physicians considering vaccinating infants aged <9 months 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.
Hepatitis A Vaccine or Immune Globulin for Hepatitis A
Infants and children traveling to low income countries are at increased risk for acquiring hepatitis A virus (HAV) infection, especially if their travel is outside usual tourist routes, if they will be eating food or drinking water in settings of questionable sanitation, or if they will be in contact with local residents in settings of poor sanitation. 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. IG should be given to infants <2 years of age in the same schedule as that recommended for adults (Table 3–7). Children 2 or more years of age should receive the pediatric formulation of HAV vaccine or IG. The first dose of vaccine should be administered as soon as travel to countries with high or intermediate endemicity is considered. Many children will have responded to the vaccine by 2 weeks after the first vaccine dose. One month after receiving the first dose of hepatitis A vaccine, 94%–100% of adults and children will have protective concentrations of antibody. However, travelers who need optimal protection earlier than 4 weeks after the first dose of vaccine should also receive IG at a different injection site.
Meningitis primarily affects children and adolescents, with high morbidity and mortality rates. Vaccination is recommended for travel to a disease-endemic area during the dry seasons. The currently available vaccine in the United States is a tetravalent polysaccharide vaccine (unconjugated.) A conjugated vaccine is in large-scale trials and appears to provide good efficacy in children <2 years of age. With the current vaccine, children <2 years old may be able to generate a partial response to serotype A; thus, vaccinating infants going to high-risk areas can provide some degree of protection.
Japanese encephalitis vaccine
JE is transmitted by primarily night-biting Culex mosquitoes in rural areas of Asia and the Pacific Rim. Most reported cases are in children. Although asymptomatic or very minor infections exist in disease-endemic areas, symptomatic infections have up to 25% mortality and 30%-80% incidence of neurologic deficits in survivors. 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.
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, throughout the year in the tropics). Children at high risk for complicated influenza infections should be vaccinated, including those with asthma, cystic fibrosis, and other pulmonary diseases; hemodynamically significant cardiac disease; immunosuppressive disorders or therapy; sickle-cell anemia and other hemoglobinopathies; diseases requiring long-term aspirin therapy; and chronic renal or endocrine diseases.
Approximately 15,000 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, a prospective parent or parents must fulfill the requirements set by the Bureau of Citizenship and Immigration Services (formerly the Immigration and Naturalization Service [INS]), the foreign country in which 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 an BCIS-approved petition (BCIS Form I-600A: Application for Advance Processing of Orphan 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 adoptee.
Adoptive parents who go 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 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 Examination for Internationally Adopted Children
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 any 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 or child's immigration.
The medical examination procedure consists of a brief physical examination and 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 Naturalization Act requires that any person seeking an immigrant visa for permanent residency must show proof of having received the recommended vaccines (as established by the Advisory Committee on Immunization Practices [ACIP]; see Chapter 1, Vaccination Information) 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 or child's arrival in the United States.
Additional information about the medical examination and the vaccination exemption for internationally adopted children is available on the Department of State website at http://www.travel.state.gov/adopt.html.
Follow-Up Medical Examination after Arrival in 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 resource-poor 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, 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 are among the most common medical diagnoses and 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 surface antigen, hepatitis B surface antibody, hepatitis B core antibody; HIV serology, syphilis serology, Mantoux (Purified Protein Derivative, PPD) intradermal skin test, 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, as many of these adopted children acquire HAV infection early in life, and are therefore immune, and chronic HAV infection does not occur. Internationally adopted children should be screened for hepatitis B infection. Presence of surface antigen indicates ongoing infection with the hepatitis B virus and potential for liver injury and spread to family members. If a child is HBsAg positive, all unvaccinated household contacts should receive the full vaccine series. Infants and children from Asia or Eastern Europe should be screened for hepatitis C, as should children from other areas if the records indicate potential risk factors such as receipt of blood products or maternal drug use. Testing for hepatitis D should be considered in children from the Mediterranean area, Africa, Eastern Europe, and Latin America who are infected with hepatitis B.
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 polymerasechain reaction. Two negative tests obtained 1 month apart are required for the child to be considered uninfected.
Mantoux (PPD) skin testing is recommended for international adoptees because their rates of TB infection are several times higher than in U.S.-born children. The definition of a positive tuberculin skin test for children born in regions of the world with high TB prevalence is 10mm of induration. If the skin test 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 PPD testing. 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 is not fully protective and because of the high risk for exposure in most countries where BCG is given, the AAP recommends that children with a positive PPD skin test be given 9 months of isoniazid therapy.
Up to 35% of internationally adopted children have ova or parasites identified on stool examinations. Internationally adopted children should be screened initially and then at any time if enteric symptoms develop, even years after arrival in the United States. For Giardialamblia infection, stool examination for antigen by enzyme immunoassay may be more sensitive than microscopic exam. This infection is particularly prevalent in internationally adopted children from Eastern Europe.
Internationally adopted children should be carefully examined for scabies and pediculosis, so that they can be appropriately treated and so that family members and contacts do not become infested.
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 URL: 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 prescribing drugs that can cause hemolysis in persons who have G6PD deficiency.
Internationally adopted infants and children frequently are underimmunized and should receive necessary immunizations according to recommended schedules in the United States (see Table 7–1). When 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 to 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. Doing so is generally safe and avoids the need to obtain and interpret serologic tests. Detailed recommendations from ACIP are available in MMWR, February 8, 2002 (http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5102a1.htm).
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 polio virus. 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, and 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.
Other sources of recommendations for the medical evaluation of adopted infants and children is the American Academy of Pediatrics, including the publication 2000 Red Book: Report of the Committee on Infectious Diseases, 25th edition, and the AAP policy statement, "Initial Medical Evaluation of an Adopted Child," published in Pediatrics, Volume 88, Number 3, September 1991.
Acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV), has a very long and variable incubation period, generally lasting for many years. Some persons infected with HIV have remained asymptomatic for more than a decade. No vaccine is currently available to protect against infection with HIV. Although there is no cure for AIDS, treatment with antiretroviral therapy and prophylaxis against many opportunistic diseases associated with AIDS are available.
International travelers should be advised that some countries serologically screen incoming travelers (primarily those arriving for extended visits, such as for work or study) and deny entry to persons with AIDS and those whose test results indicate infection with HIV. Moreover, travelers carrying antiretroviral medication may be denied entry to some countries. Persons who intend to visit a country for a substantial period or to work or study abroad should be informed of the policies and requirements of the particular country. This information is usually available from the consular officials of the individual nations. An unofficial list by the U.S. Department of State can be found at the following Internet address: http://www.travel.state.gov/HIVtestingreqs.html.
Specific Precautions for HIV-Infected Travelers
Primary-care providers of HIV-infected travelers should advise their patients of the need for advance travel planning. A pre-travel consultation with a travel health practitioner who provides counseling and evaluates the risk-benefit balance of preventive actions such as prophylaxis and vaccinations can minimize the avoidable risks associated with travel.
General Concerns for HIV-Infected Travelers
Health-care providers should advise HIV-infected travelers about the following issues:
- Travel, particularly to developing countries, can carry substantial risks for exposure to opportunistic pathogens for HIV-infected travelers, especially those who are severely immunosuppressed. Discussing the itinerary with a health-care provider may identify area- and activity-specific risks that can be addressed.
- Patients should identify sources of medical care in the planned destination before departure and seek medical attention promptly when ill.
- Patients should verify medical insurance coverage and purchase additional travel insurance if necessary, though many policies will not cover pre-existing conditions.
- Because antiretroviral medications are not available in many parts of the world, patients should bring an adequate supply of their medications, along with copies of prescriptions. Attention should be given to refrigeration of medications. For extended visits, travelers should consult with their providers in advance regarding a plan for maintaining appropriate medical follow-up and supplies of medications.
- Avoid changes in the medication regimen shortly before travel, to ensure that no side effects or complications of a new regimen occur while traveling.
Disease Prevention and Treatment
Because immune status is the major factor influencing travel recommendations, patients should have their disease staged before departure.
Food and Waterborne Diseases
During travel to developing countries, HIV-infected travelers are at even higher risk for food and waterborne diseases than they are in the United States, and many enteric infections, such as those caused by Salmonella, Campylobacter, and Cryptosporidium can be very severe in HIV-infected persons.
Dietary precautions are the cornerstone of prevention against enteric infections and infections with certain other potential opportunistic pathogens. Food and beverages especially prone to contamination and that pose a greater risk for illness to HIV-infected travelers include raw or unpeeled fruits and vegetables, raw or undercooked seafood or meat, raw or undercooked eggs, tap water, ice made with tap water, unpasteurized dairy products, and items purchased from street vendors. Food and beverages that are generally safe include steaming hot foods, fruits that are peeled by the traveler personally, bottled (carbonated) beverages, hot coffee or tea, beer, wine, or water brought to a rolling boil for >1 minute. For more detailed information on food- and water-related precautions, especially concerning avoidance of listeriosis, refer to the Guidelines for Preventing Opportunistic Infections among HIV-Infected Persons—2002 (MMWR Morb Mortal Wkly Rep 2002;51 [No. RR-8]). When local sources of water must be used and boiling is not practical, certain portable water filtration units, when used in conjunction with chlorine or iodine, can increase the safety of water. Some units are available that offer the effects of iodine treatment with filtration in the same unit. For more information about how to select a proper water filter, travelers should be advised to obtain the CDC pamphlet, "You can prevent cryptosporidiosis: a guide for persons with HIV infection," available online at www.cdc.gov/travel/diseases.htm#crypto; they may also call 1-800-458-5231 or TTY 1-800-243-7012. International callers must dial 1-301-562-1098.
For information about waterborne infections that may result from swallowing water during recreational water activities.
Chemoprophylaxis for HIV-Infected Travelers to Developing Countries
Prophylactic antimicrobial agents against travelers' diarrhea are not recommended routinely because of potential adverse effects and emergence of drug resistance. In certain circumstances (e.g., an important short-term trip to an area where the risk of infection is very high), the health-care provider and traveler may decide that prophylactic antibiotics are warranted after the potential risks and benefits are weighed.
When prophylaxis is offered to travelers, fluoroquinolones such as ciprofloxacin (500 mg once a day) are the drugs of choice for nonpregnant adults, although increasing quinol one resistance in Campylobacter jejuni has been reported in Thailand and Southeast Asia. Quinolones are not approved for prophylaxis for children and pregnant women. Trimethoprim-sulfamethoxazole (TMP-SMX) (one double-strength tablet daily) was previously an effective prophylactic agent against travelers' diarrhea, but drug resistance is now common in many tropical areas. Travelers already taking TMP-SMX for prophylaxis against Pneumocystis carinii pneumonia (PCP) may receive some protection against travelers' diarrhea. However, prescribing TMP-SMX solely for diarrhea prophylaxis to HIV-infected travelers who are not already taking TMP-SMX should be considered carefully because of high rates of drug resistance in tropical areas, high rates of adverse reactions, and potential future need for the agent (e.g., for PCP treatment and prophylaxis). Use of bismuth subsalicylate should be discussed with a travel health practitioner because it confers only moderate protection and has the potential for causing adverse reactions. Total duration of any chemoprophylaxis regimen for travelers' diarrhea should not exceed 3 weeks.
Antimicrobials for Empiric Therapy
All HIV-infected travelers to developing countries should be advised to carry an antimicrobial agent with them for empiric use should diarrhea develop; one appropriate regimen is 500 mg of ciprofloxacin twice a day for 3–7 days. Alternative antibiotics (e.g., TMP-SMX, azithromycin) for empiric treatment of children and pregnant women should be considered on a case-by-case basis. Travelers should be advised to consult a physician if any of the following conditions are present: severe diarrhea that does not respond to empirical therapy, blood in the stool, fever with or without shaking chills, or dehydration. Antiperistaltic agents (e.g., diphenoxylate [Lomotil] and loperamide [Imodium]) can be used to relieve the symptoms of mild diarrhea; however, they should not be used by travelers who have high fever or blood in the stool and should be discontinued if symptoms persist >48 hours. Antiperistaltic agents are not recommended for HIV-infected infants, children, or adolescents.
Other precautions. Travelers should avoid direct skin contact with soil and sand (e.g., by wearing shoes and protective clothing and using towels on beaches) in areas where fecal contamination of soil is likely.
Sexually transmitted diseases. The importance of safe sex practices should be emphasized to the HIV-infected traveler to prevent other sexually transmitted diseases, avoid transmission of HIV to others, and prevent acquisition of different HIV strains that may limit therapeutic options (e.g., non-nucleoside reverse transcriptase inhibitors are not active against HIV-2). Bringing a personal supply of condoms may be advisable, as the quality and availability of condoms can be unreliable in parts of the developing world.
Health-care providers should identify other area-specific risks and instruct travelers in ways to reduce the risk of infection. Geographically focal infections that pose high risk to HIV-infected travelers include the following:
Malaria and other vector-borne diseases (see Disease-Specific Recommendations for additional information). Travelers should be advised to follow standard mosquito precautions, such as using insect repellents, wearing long-sleeved clothing and pants when outdoors, and sleeping in well-screened areas or with a bed net. Malaria chemoprophylaxis for HIV-infected travelers follows the same guidelines as those for seronegative persons. However, potential drug interactions between antimalarials and antiretroviral agents should be considered; for specific advice about such interactions, contact the CDC Malaria Hotline at 770-488-7788.
Visceral leishmaniasis (VL). VL, a protozoan infection transmitted by the bite of the sandfly, is an important opportunistic infection in HIV-infected patients. Although >90% of the world's cases of VL occur in Bangladesh, Brazil, India, Nepal, and Sudan, most cases of VL and HIV co-infection have been reported from the Mediterranean Basin (especially Spain, France, and Italy). Clinical disease usually occurs in patients with a CD4 count <200 cells/μL as a result of reactivation of latent infection, although primary infection has been reported. Treatment of VL with HIV co-infection is difficult, and relapse is common. Travelers, especially those who are immunosuppressed, should be advised to follow precautions against sandfly bites, as described in "Disease-Specific Recommendations: Leishmaniasis"; further details on other regions where travelers incur risk for VL are also available in that section. Cutaneous leishmaniasis has rarely been reported as an opportunistic infection in HIV-infected patients.
Endemic mycoses in certain regions can also pose a substantial risk for HIV-infected travelers. Penicillium marn-effei is endemic to Southeast Asia and southern China, and clinical disease may occur after reactivation of latent infection as immunosuppression increases. Penicilliosis has occurred in AIDS patients with a remote history of only brief travel to endemic areas. Although the environmental reservoir is unknown, soil exposure is a known risk factor and should be avoided in those areas, especially during the rainy season.
Coccidioides immitis, Histoplasma capsulatum, and Cryptococcus neoformans, which cause opportunistic infections in North America, are also present in the tropics. C. immitis is endemic to the southwest United States, northern Mexico, and certain areas of Central and South America, while H. capsulatum and C. neoformans are distributed worldwide. Risk of infection can be minimized by avoiding exposure to disturbed soil in the Americas (C. immitis) and avoiding soil or dust exposure in areas likely to be contaminated heavily with bird or bat guano, such as caves or bird roosting sites (H. capsulatum and C. neoformans).
Tuberculosis. Many tropical and developing areas of the world also have high rates of tuberculosis (see "Disease-Specific Recommendations: Tuberculosis").
Vaccine Recommendations for Travelers with Altered Immunocompetence, Including HIV
Preparation for travel should include a review and updating of routine vaccinations. At a minimum, HIV-infected adults should be current on the routinely recommended pneumococcal, diphtheria-tetanus, Hepatitis B, and influenza vaccines. Influenza is a year-round infection in the tropics; in the Southern Hemisphere the influenza season is April through September. All routine immunizations for infants, children, and adolescents should also be confirmed and administered as appropriate.
In determining the need for other vaccinations, factors to consider include the immune status of the patient, risk for and severity of the disease in the destination region, and type of vaccine. In general, killed or inactivated vaccines (e.g., hepatitis A, rabies, meningococcus, hepatitis B, and Japanese encephalitis vaccines) should be administered to HIV-infected travelers as recommended for non-HIV-infected travelers. When appropriate, the inactivated forms of the polio and typhoid vaccines should be given instead of the live, attenuated forms. Most live virus vaccines are contraindicated, especially if the patient's CD4 count is <200 cells/μL. The measles and yellow fever vaccines, however, are special cases in which live virus vaccination may be warranted.
Measles vaccine is a live virus vaccine that is recommended for most nonimmune travelers, given the increased severity of measles in HIV-infected patients. However, measles vaccine is not recommended for travelers who are severely immunocompromised; immune globulin should be considered for measles-susceptible, severely immunosuppressed travelers who are anticipating travel to measles-endemic countries.
Yellow fever vaccine is a live virus vaccine with uncertain safety and efficacy in HIV-infected patients. Travelers with asymptomatic HIV infection and minimal immunosuppression, as documented by laboratory tests such as CD4 counts, who cannot avoid potential exposure to yellow fever should be offered the choice of vaccination. If travel to a yellow fever zone is necessary and immunization is not performed, travelers should be advised of the risk, instructed in methods to avoid mosquito bites, and provided a vaccination waiver letter. Patients should also be warned that vaccination waiver documents may not be accepted by some countries.
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