PRE-TRAVEL PLANNING

Preparing an HIV-infected individual for international travel requires attention to a number of important issues, which, for the most part, are similar to those that must be faced by any compromised traveler. These considerations include:

• restrictions for crossing international borders,
• vaccination requirements and their efficacy and safety,
• susceptibility to infections present at the destination, and
• accessibility of reliable health care overseas and the possible need for medical evacuation home.

RESTRICTIONS FOR CROSSING INTERNATIONAL BORDERS

Many countries, particularly those in Eastern Europe and the Middle East, currently restrict entry of travelers with HIV infection or AIDS and insist on HIV antibody testing for foreigners as a requirement of entry. These regulations apply mostly to students, workers, and others applying for long-term entry permits, although, in a few countries, visitors staying for as short a time as 2 weeks are required to be tested. Some countries insist on HIV testing after arrival and will not accept the results of testing done elsewhere. Notable exceptions include Colombia and the United States, which currently deny entry to anyone suspected of being HIV positive. The U.S. State Department web site contains unofficial information on HIV testing requirements for entry into foreign countries (travel.state.gov/HIVtestingreqs.html).

However, since HIV test requirements exceed the jurisdiction of the International Health Regulations, countries do not report them to the World Health Organization or to any other central reporting agency. Consequently, travelers are advised to contact the embassies or consulates of destination countries prior to departure and to inquire about HIV test requirements, as well as other possible health-related visa requirements (immunizations, TB test, chest x-ray, etc.).

SUSCEPTIBILITY TO INFECTIONS

Enteric infections

During travel to developing countries, HIV-infected persons are at greater risk for severe illness from food and waterborne diseases, such as Salmonella sp., Cryptosporidium parvum, Isospora belli, Microsporidia, and Cyclospora sp.

Greater attention to food and water precautions is particularly important. To prevent cryptosporidium, an infection which is resistant to chlorination or iodination, beverages should be commercially bottled, brought to a rolling boil for 1 minute, or filtered (pore size < 1 micron). The CDC's travel web site, www.cdc.gov/travel, contains a guide for the prevention of cryptosporidiosis for people with HIV infection. Also, to reduce the risk of cryptosporidiosis from water swallowed during recreational water activities, HIV-infected travelers should avoid swallowing water during swimming in water that may be contaminated (e.g., with sewage or animal waste).

All HIV-infected travelers to developing countries should carry an antimicrobial with them to be taken as empirical therapy should diarrhea develop (e.g., ciprofloxacin, 500 mg bid for 3 to 5 days). In selected circumstances (e.g., a brief period of travel to an area where the risk of infection is high), prophylactic antibiotics may be warranted; fluoroquinolones (levofloxacin, ofloxacin, ciprofloxacin, norfloxacin), 1 tablet daily, are considered the drugs of choice. (For individuals who cannot tolerate quinolones, azithromycin is a reasonable second option, although there are no data on its use for prophylaxis of traveler's diarrhea.) Since diarrhea is a frequent complication of HAART, those taking this regimen should receive counseling regarding the symptoms of enteric infections.

Respiratory infections

Pneumococcal infections, influenza, and tuberculosis are important risks for the HIV-infected traveler. The risk of tuberculosis increases with duration of travel and close contact with the indigenous population of developing countries. A pre- and post-travel tuberculin skin test is mandatory for long-stay travel greater than 3 months in developing countries and the states of the former Soviet Union where tuberculosis risk is high. This is especially important for health care providers and others who are likely to have close contact with locals (e.g., staying in local homes). If a cruise is to be undertaken more than 6 months after influenza immunization, a second dose should be administered before departure. Immunocompromised HIV-infected travelers should consider carrying self-treatment for influenza for high-risk travel (e.g., cruise), since the immune response to vaccination may be poor.

Progressive, disseminated infection may follow primary exposure to coccidioidomycosis from contaminated soil in rural endemic areas of southwestern United States, northern Mexico, and parts of Central and South America. Consideration should be given to a limited course of prophylaxis with fluconazole or itraconazole for travelers to areas with endemic coccidioidomycosis. HIV-infected travelers should also be told about the risk of histoplasmosis in bat-infested caves and therefore be counseled against spelunking.

Insect-borne pathogens

HIV-infected travelers should take extra precautions to prevent bites of insect vectors that have the potential to transmit infections that are known to cause severe illness in immunocompromised persons, in particular, sandflies (visceral leishmaniasis) and reduviid bugs (Chagas' disease). Travelers must also be made aware that, for them, scabies carries the threat of overwhelming infection and potential bacterial superinfections.

ACCESS TO HEALTH CARE

VACCINATION REQUIREMENTS, SAFETY, AND EFFICACY

The benefits and risks of immunization for international travel need to be carefully addressed in individuals infected with HIV. The following issues must be considered:

• Killed or inactivated vaccines are safe whereas live vaccines may be harmful due to increased viral replication in the immunocompromised individual.
• Although HIV-1 viral replication increases transiently after vaccination, there is no evidence to show that vaccination has detrimental long-term effects on patient survival.
• Immune responses to vaccination of HIV-infected individuals are not predictable and are likely to be diminished in proportion to the degree of immunosuppression. All immunizations should be administered as early in the course of HIV disease as possible; immunization after the initiation of HAART may be beneficial.
• Individuals infected with HIV (with low CD4 counts) are at greater risk of complications from vaccine preventable infections.

Live vaccines

In general, live organism vaccines should be avoided by persons with AIDS or persons who are HIV-positive. However there are 2 exceptions to this rule: measles-containing vaccines and varicella vaccine.

Measles: MMR vaccine is recommended for HIV-infected persons who are asymptomatic. MMR vaccine should be considered for HIV-infected persons who are symptomatic but not severely immunocompromised. MMR or other measles-containing vaccines should NOT be given to HIV-infected persons with evidence of severe immunosuppression (i.e., CD4+ T-lymphocyte counts less than 100/mL). Healthy susceptible close contacts of a severely immunosuppressed person may be vaccinated. Immunoglobulin should be considered for severely immunosuppressed persons who are susceptible to measles and anticipate travel to measles-endemic areas.

Varicella: Varicella vaccine should not be given to persons with cellular immunodeficiencies but may be given to persons with impaired humoral immunity. In addition, some HIV-infected children may now be considered for vaccination. Varicella vaccine should be considered for asymptomatic or mildly symptomatic children in CDC class N1 or A1 with age-specific CD4+ T-lymphocyte percentages of 25% or higher. Eligible children should receive 2 doses of varicella vaccine with a 3-month interval between doses.

Yellow fever vaccine may be offered as an option to asymptomatic persons with HIV infection only if the risk of exposure is unavoidable and the CD4 count is above 200/mL. If travel to a yellow fever-infected zone is necessary and immunization is not performed, a vaccination waiver letter should be provided. Furthermore, since the immune response to the vaccine may be diminished, advise all patients of the risk and instruct them on methods to avoid insect bites (particularly during the day).

Oral typhoid vaccine should not be given to HIV-infected persons. BCG vaccine is no longer recommended for any HIV-infected person in the United States.

Inactivated vaccines

HIV-infected patients should receive influenza vaccine on an annual basis, particularly prior to travel. If a cruise is to be undertaken more than 6 months after the immunization, a second dose should be administered before departure². Pneumococcal vaccine should be given. Revaccination should be considered if 5 years have elapsed since the initial dose. If the patient is < 10 years of age, consider a single revaccination 3 to 5 years after the initial dose³.

Td (and DTaP) immunization should be up-to-date. Follow routine schedule. Injectable polio vaccine (IPV) is recommended for HIV-infected persons and their household contacts. Follow routine schedule. Persons at risk for exposure to typhoid fever should be given the inactivated, parenteral typhoid vaccine.

Hepatitis B immunization should be considered. Follow routine schedule. The anti-HBs response of persons with HIV infection should be tested after they are vaccinated, and those who do not respond should be revaccinated with 1 to 3 additional doses. Rabies vaccine may be given, but the immune response for preexposure prophylaxis may be inadequate and thus the IM route should be used. When rabies postexposure prophylaxis is administered to persons with HIV infection, it is important that the patient's serum be tested for rabies antibody to ensure that an adequate response has developed.

Japanese encephalitis, meningococcal, and hepatitis A vaccines and/or immune globulin may be given if appropriate for the itinerary. Hib vaccine generally is not recommended for adults with HIV infection. Providers should weigh the individual's risk of the disease against the effectiveness of the vaccines, the immunogenicity of which varies with the stage of HIV infection.

HIV-positive patients should have a tuberculin test (PPD) as part of their routine medical care and particularly before and after international travel to high-risk areas.

Immunizing Children Infected with HIV

For children infected with HIV, the following changes from the routine childhood immunization schedule are recommended:

• MMR vaccine should not be given to severely immunocompromised children. However, HIV-infected children without severe immunosuppression should receive their first dose of MMR as soon as possible upon reaching the first birthday. Consideration should be given to administering the second dose of MMR vaccine as soon as 1 month (28 days) after the first dose, rather than waiting until school entry.
• Influenza vaccine should be given annually to all symptomatic HIV-infected children > 6 months of age. Also consider giving influenza vaccine to asymptomatic children age 6 months and older. (See Influenza vaccine, Administration.)
• Varicella vaccine should now be considered for HIV-infected children who are asymptomatic or mildly symptomatic (in CDC class N1 or A1 with age-specific CD4+ T-lymphocyte percentages > 25%). Eligible children should receive 2 doses with a 3-month interval between doses.

Follow the routine childhood schedule for Hib vaccine and Hepatitis B vaccine. The anti-HBs response of persons with HIV infection should be tested after the persons are vaccinated, and those who do not respond should be revaccinated with 1 to 3 additional doses⁴.

HIV-positive travelers should have a tuberculin test (PPD) as part of their routine medical care, but especially before and after travel to risk areas (see Tuberculosis). BCG vaccine is no longer recommended for any HIV-infected person in the USA.

For additional information on vaccinating HIV-infected children, see Table 18, Recommended Immunization Schedule for HIV-Infected Children, and Arpade SM, Infect Med 14, No. 9: 720-724, 1997, Recommendations for vaccinating HIV-infected children.

SUMMARY: ADVICE FOR HEALTH CARE PROVIDERS OF HIV-INFECTED TRAVELERS

• Discuss issues and risks of travel. Are the benefits worth the risks?
• Discuss travel plans and administer vaccines at least 6 to 8 weeks before departure.
• Ascertain current CD4 cell count. For prolonged travel, consider PPD.
• Advise traveler to check anonymously consulates and/or embassies for any travel restrictions for HIV-infected persons at an intended destination. Check U.S. State Department website: travel.state.gov/HIVtestingregs. Gay travelers should also consult gay travel agencies and travel related publications for further information on countries with discriminatory practices toward those found to have antiretroviral agents in their baggage.
• Ensure that the traveler has a letter summarizing clinical status and medical history; if possible, provide a name(s) of an HIV-knowledgeable physician at the destination.
• Encourage purchase of flexible and fully refundable ticket or trip cancellation insurance and appropriate medical insurance with provision for emergency assistance.
• Encourage food and drink precautions and personal protection measures against insect bites.
• Discuss common illnesses and appropriate treatment measures for problems such as diarrhea and sinusitis. Consider daily antibiotic prophylaxis for traveler's diarrhea (usually a quinolone) for high-risk travel of less than 4 weeks duration.