HIV, a single-stranded, positive-sense, enveloped RNA virus in the genus Lentivirus.
HIV can be transmitted through sexual contact, needle- or syringe-sharing, medical use of blood or blood components, organ or tissue transplantation, and artificial insemination. It can also be transmitted from mother to child during pregnancy, at birth, and postpartum through breastfeeding. HIV may be transmitted occupationally to health care workers who are exposed to blood and other potentially infectious bodily fluids via percutaneous injury or splash exposures to mucous membranes or non-intact skin (see Chapter 8, Health Care Workers). HIV is not transmitted through casual person-to-person contact; air, food, or water; contact with inanimate objects; or by mosquitoes or other arthropod vectors. The use of any public conveyance (such as airplanes, automobiles, boats, buses, or trains) by people with HIV infection does not pose a risk of HIV infection for the crew members or other travelers.
HIV infection occurs worldwide. As of the end of 2012, an estimated 35 million people were living with HIV infection. Although sub-Saharan Africa has experienced a substantial decline in the number of new infections annually, from 2,600,000 in 2001 to 1,600,000 in 2012, and a decline in prevalence during the same period, from an estimated 5.8 to 4.7 infections per 100,000 people, it remains the most affected part of the world (25 million cases or 71% of all people living with HIV infection). Notable increases in HIV infection have occurred in Eastern Europe and Central Asia, where the number of people living with HIV infection from 2001 to 2012 rose from an estimated 860,000 to 1,300,000. Most new infections come from low- and middle-income countries. Many countries lack comprehensive surveillance systems and, despite improvements, the true number of cases may be higher than officially reported, particularly in developing countries.
The risk of HIV infection for international travelers is generally low, although the risk is determined less by geographic destination and more by behaviors such as drug use and unprotected sex. Travelers who might undergo medical procedures, whether scheduled or in an emergency, should be aware that in developing countries the blood supply (and organs and tissues used for transplantation) might not be adequately screened, increasing the risk of HIV transmission.
Any person who suspects that she or he may have been exposed to HIV should be tested. Most people develop detectable antibodies within 2–8 weeks (mean, 25 days). Ninety-seven percent of people develop antibodies in the first 3 months after infection. In rare cases, it can take up to 6 months to develop antibodies to HIV. After being infected, a person remains antibody positive for life, except when people lose the capacity to mount detectable antibodies in the latest stages of the disease. The earliest time after exposure that HIV infection can be diagnosed is approximately 9 days, when HIV RNA becomes detectable in blood; however, tests needed to measure HIV RNA are costly and may not be available. Any person not known to be HIV-infected who is diagnosed with an AIDS-compatible illness, such as Pneumocystis pneumonia, should be tested for HIV. For further information on HIV testing, travelers should talk to their health care provider, or identify an HIV testing site near them by visiting the National HIV Testing Resources website at www.hivtest.org or call CDC-INFO toll-free at 800-CDC-INFO (800-232-4636) or 888-232-6348 (TTY). Both these resources are confidential.
Prompt medical care and effective treatment with antiretrovirals can inhibit HIV from damaging the immune system and delay progression of disease. Effective treatment also substantially reduces the risk of HIV transmission to others. US guidelines recommend all people with HIV infection be treated for their own health and to prevent transmission to others. Detailed information on specific treatments is available from the Department of Health and Human Services AIDSinfo (www.aidsinfo.nih.gov). Information on enrolling in clinical trials is also available at AIDSinfo. Travelers may contact AIDSinfo toll-free at 800-448-0440 (English or Spanish) or 888-480-3739 (TTY).
No vaccine is available to prevent infection with HIV. Travelers should be advised that they are at risk if they
Have sexual contact (heterosexual or homosexual) with an infected person or a person whose HIV infection status is unknown.
Use or allow the use of contaminated, unsterilized syringes or needles for any injections or other procedures that pierce the skin, including acupuncture, use of illicit drugs, steroid or vitamin injections, medical or dental procedures, ear or body piercing, or tattooing.
Receive infected blood, blood components, or clotting factor concentrates. HIV infection by this route is rare in countries or cities where donated blood and plasma are screened for antibodies to HIV.
Work in a health care setting. Typically, exposures occur as a result of percutaneous exposure to contaminated sharps, including needles, lancets, scalpels, and broken glass (from capillary or test tubes). See Chapter 8, Health Care Workers.
To reduce their risk of acquiring HIV, travelers should
Avoid sexual encounters with people who are infected with HIV, whose HIV infection status is unknown, or who are at high risk for HIV infection, such as intravenous drug users, commercial sex workers (both male and female), and other people with multiple sexual partners
Use condoms consistently and correctly, especially if engaging in vaginal, anal, or oral sex with a person who is HIV infected or whose HIV status is unknown
Avoid injecting drugs
Avoid sharing needles or other devices that can puncture skin
Avoid, if at all possible, blood transfusions or use of clotting factor concentrates
Ensure that if traveling for purposes of medical treatment (see Chapter 2, Medical Tourism), the blood and blood products used in the facility where the traveler will be treated are screened for HIV, and that such facilities exercise proper infection control practices
Consider discussing using preexposure prophylaxis (www.cdc.gov/hiv/prep) with a health care provider, especially if the traveler is sexually active with >1 partner and does not use condoms consistently during sex
People who are sensitive to latex should use condoms made of polyurethane or other synthetic materials (not lambskin) and should carry their own supply of male or female condoms. If no condom is available, travelers should abstain from sex with people who are HIV-infected or whose HIV status is unknown. Barrier methods other than condoms do not prevent HIV transmission. Spermicides alone are also not effective. The widely used spermicide nonoxynol-9 can increase the risk of HIV transmission and should not be used.
Needles used to draw blood or administer injections should be sterile, single use, disposable, and prepackaged in a sealed container. If at all possible, travelers should avoid receiving medications from multidose vials, which may have become contaminated by used needles. Travelers with type 1 diabetes, hemophilia, or other conditions that necessitate routine or frequent injections should be advised to carry a supply of medication, syringes, needles, and disinfectant swabs sufficient to last their entire stay abroad. These travelers should request documentation of the medical necessity for traveling with these items (a letter from a licensed health care provider) to avoid having them confiscated, such as by inspection personnel at ports of entry (see Chapter 2, Travel Health Kits for more information about traveling with medications).
In many developed countries, the risk of HIV infection through transfusion of blood or blood products has been virtually eliminated through required testing of all donated blood. Developing countries may have no formal program, or may have inadequate technology for testing blood or biological products for contamination with HIV. If transfusion is necessary, the blood should be tested for HIV antibodies by trained laboratory technicians using a reliable test.
Travelers who will be working in a medical setting (such as a nurse volunteer drawing blood or medical missionary performing surgeries) may have contact with HIV-infected or potentially infected biological materials. Detailed advice regarding management of postexposure prophylaxis in the occupational setting is found in Chapter 8, Health Care Workers. General recommendations on postexposure prophylaxis include the following:
People who have been exposed to HIV in a nonoccupational setting (through sex or needle sharing) should seek immediate medical consultation to consider postexposure prophylaxis.
Postexposure prophylaxis for potential exposure to HIV as a result of mass-casualty events is generally not warranted, except in special circumstances (for example, a blast injury in a facility that contained a large archive of HIV-infected blood specimens).
Clinicians seeking advice on postexposure prophylaxis can call the US National HIV/AIDS Clinicians’ Consultation Center PEPline toll-free at 888-448-4911 (www.nccc.ucsf.edu).
HIV TESTING REQUIREMENTS FOR US TRAVELERS ENTERING FOREIGN COUNTRIES
International travelers should be advised that some countries screen incoming travelers for HIV infection and may deny entry to people with AIDS or evidence of HIV infection. These countries usually screen only people planning extended visits, such as for work or study. People intending to visit a country for an extended stay should review that country’s policies and requirements. This information is usually available from the consular officials of the individual nations. Information about entry and exit requirements compiled by the Department of State can be found at http://travel.state.gov/travel/tips/tips_1232.html#requirement.
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Smith DK, Grohskopf LA, Black RJ, Auerbach JD, Veronese F, Struble KA, et al. Antiretroviral postexposure prophylaxis after sexual, injection-drug use, or other nonoccupational exposure to HIV in the United States: recommendations from the US Department of Health and Human Services. MMWR Recomm Rep. 2005 Jan 21;54(RR-2):1–20.