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: www.travel.state.gov/HIVtestingreqs.html.
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.
Health-care providers should advise HIV-infected travelers about the following issues:
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, see "Swimming and Recreational Water Precautions."
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 quinolone 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 marneffei 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).
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 (see below).
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.