John T. Brooks

Infectious Agent

AIDS is a serious disease that represents the late clinical stage of infection with human immunodeficiency virus (HIV). HIV progressively damages the immune system. Without an effective immune system, life-threatening infections and other noninfectious conditions related to failing immunity (such as certain cancers) eventually develop.

Mode of Transmission

HIV can be transmitted through—

• Sexual intercourse
• Needle- or syringe-sharing
• Medical use of blood or blood components
• Organ or tissue transplantation
• Artificial insemination
• Pregnancy (perinatally from an infected woman to her infant).

HIV is not transmitted through casual contact; air, food, or water routes; contact with inanimate objects; or by mosquitoes or other arthropod vectors. The use of any public conveyance (e.g., airplanes, automobiles, boats, buses, or trains) by persons with AIDS or HIV infection does not pose a risk of HIV infection for the crew members or other travelers.

Occurrence

• AIDS and HIV infection occur worldwide.
• As of the end of 2007, over 33 million persons were living with HIV/AIDS. Although sub-Saharan Africa remains the most affected part of the world, notable increases in HIV infection have occurred from 2001 to 2007 in Eastern Europe and throughout Asia (Map 5-5).
• Many countries lack comprehensive surveillance systems, and despite improvements, the true number of cases is likely greater than officially reported, particularly in developing countries.

Risk for Travelers

• The risk of HIV infection for international travelers is generally low.
• Because HIV infection and AIDS are distributed globally, the risk for international travelers is determined less by geographic destination and more by behaviors that put them at risk for becoming infected, such as sexual and drug-using behaviors.
• Factors to consider in assessing risk include the extent of sexual contact with potentially infected persons and the extent of direct contact with blood or other potentially infectious secretions.
• In developing countries, the blood supply might not be adequately screened, thereby increasing the risk of HIV transmission by transfusion.

Diagnosis

• Any person who suspects that she or he may have been exposed to HIV infection should be tested.
• Most HIV tests are antibody tests that measure the antibodies the body makes against HIV. It can take some time for the immune system to produce enough antibodies for the antibody test to detect, and this time period (commonly referred to as the “window period”) can vary from person to person.
• Most people will develop detectable antibodies within 2–8 weeks (the average is 25 days). Ninety-seven percent of persons will develop antibodies in the first 3 months following infection. In very rare cases, it can take up to 6 months to develop antibodies to HIV.
• If the initial negative HIV test was conducted within the first 3 months after possible exposure, repeat testing should be considered >3 months after the exposure occurred to account for the possibility of a false-negative result.
• Another type of test is an RNA test, which detects the HIV virus directly. The time from HIV infection to RNA detection is 9–11 days. These tests, which are more costly and used less often than antibody tests, are used in some parts of the United States.
• For information on HIV testing, travelers should talk to their health-care provider or identify the location of 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), in English or Spanish. Both these resources are confidential.
• Diagnosis of HIV infection and AIDS may also be made when a patient presents with an AIDS-compatible diagnosis, such as pneumocystis pneumonia, and is subsequently found to be HIV seropositive.

(From 2008 Report on the global AIDS epidemic. Data used by kind permission of Joint United Nations Programme on HIV/AIDS (UNAIDS) www.unaids.org.)

Treatment

• Prompt medical care may delay the onset of AIDS and prevent some life-threatening conditions.
• Travelers who become HIV infected should seek the care of a licensed health-care provider, preferably a provider with experience treating people living with HIV infection, as soon as possible after learning they are infected.
• Detailed information on specific treatments is available from the Department of Health and Human Services’ AIDSinfo, see www.aidsinfo.nih.gov/. Information on enrolling in clinical trials is also available at AIDSinfo. Travelers may contact AIDSinfo by phone, toll-free 800-448-0440 (English or Spanish) or 888-480-3739 (TTY).

Preventive Measures for Travelers

• 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.
  • 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.
• To reduce their risk of acquiring HIV, travelers should be advised to—
  • Avoid sexual encounters with persons who are infected with HIV or 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 persons with multiple sexual partners.
  • Use condoms consistently and correctly if sexually active, especially if engaging in vaginal, anal, or oral–genital sexual contact with a person who is HIV-infected or whose HIV status is unknown.
  • Avoid using intravenous drugs.
  • Avoid sharing needles or other devices that can puncture skin for any purpose.
  • Avoid, if at all possible, blood transfusions or use of blood-clotting factor concentrates.

Additional Notes

Condoms

• Persons who are sensitive to latex should use condoms made of polyurethane or other synthetic materials and should carry their own supply of condoms.
• When a male condom cannot be used properly, a female condom should be considered.
• When no condom is available, travelers should abstain from vaginal, anal, and oral–genital sexual contact with persons who are HIV infected or whose HIV status is unknown. Barrier methods other than condoms have not been shown to be effective in the prevention of HIV transmission.
• Spermicides alone have also not been shown to be effective. The widely used spermicide nonoxynol-9 can increase the risk of HIV transmission and should not be used.

Needles

• 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 insulin-dependent 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 (e.g., alcohol wipes) sufficient to last their entire stay abroad. Before traveling, such persons should consider requesting documentation of the medical necessity for traveling with these items (e.g., a doctor’s letter) in case their need is questioned by inspection personnel at ports of entry.

Transfusions

• In many developed countries, the risk of transfusion-associated HIV infection has been virtually eliminated through required testing of all donated blood for HIV.
• Developing countries may have no formal program or inadequate technology for testing blood or biological products for contamination with HIV.
• If transfusion is necessary, the blood should be tested, if at all possible, for HIV antibody by trained laboratory technicians using a reliable test.

Postexposure Prophylaxis

• Persons who in the course of their travel (e.g., nurse volunteer drawing blood or medical missionary performing surgeries) may have contact with HIV-infected or potentially infected biological materials should ensure that they will have access to all personal protective equipment necessary (e.g., latex gloves, goggles, face shield, gowns) and that this equipment meets established international quality standards.
• Such travelers may also wish to consider familiarizing themselves with the principles of postexposure prophylaxis and, in the event of a high-risk exposure, establishing a plan for seeking medical consultation and bringing a supply of antiretroviral medication of sufficient quantity to provide postexposure prophylaxis until medical care can be obtained (see theOccupational Exposure to HIV section in Chapter 2).
• The efficacy of postexposure prophylaxis with antiretrovirals for nonoccupational exposures to HIV (e.g., sexual, injecting drug use) has not been established. CDC recommends it be considered as an unproven clinical intervention, after careful consideration of potential risks and benefits and with full awareness of gaps in current knowledge.

HIV Testing Requirements for U.S. Travelers Entering Foreign Countries

• International travelers should be advised that some countries screen incoming travelers for HIV infection and may deny entry to persons with AIDS or evidence of HIV infection. These countries usually screen only persons planning extended visits, such as for work or study.
• Persons intending to visit a country for an extended stay should be informed of 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 U.S. Department of State can be found at http://travel.state.gov/travel/tips/tips_1232.html#requirement.

References

1. UNAIDS; WHO. AIDS epidemic update: 2007 [Internet]. Geneva: UNAIDS; 2007. [cited 2008 Nov 30]. Available from:http://data.unaids.org/pub/EPISlides/2007/2007_epiupdate_en.pdf (PDF).
2. Memish ZA, Osoba AO. Sexually transmitted diseases and travel. Int J Antimicrob Agents. 2003;21(2):131–4.
3. Wright ER. Travel, tourism, and HIV risk among older adults. J Acquir Immune Defic Syndr. 2003;33(Suppl 2):S233–7.
4. DC. HIV Prevention bulletin: medical advice for persons who inject illicit drugs [Internet]. Atlanta: Centers for Disease Control and Prevention. [updated 2007 Dec 26; cited 2006 May 31]. Available from: http://www.cdc.gov/idu/pubs/hiv_prev.htm.
5. Panlilio AL, Cardo DM, Grohskopf LA, et al.; U.S. Public Health Service. Updated U.S. Public Health Service guidelines for the management of occupational exposures to HIV and recommendations for postexposure prophylaxis. MMWR Recomm Rep. 2005;54(RR-9):1–17
6. CDC. Management of possible sexual, injecting-drug-use, or other nonoccupational exposure to HIV, including considerations related to antiretroviral therapy. Public Health Service statement. MMWR Recomm Rep. 1998;47(RR–17):1–14.
7. UNAIDS; WHO. 2008 Report on the global AIDS epidemic [Internet]. Geneva: UNAIDS; 2008. [cited 2008 Nov 30]. Available from: www.unaids.org/en/KnowledgeCentre/HIVData/GlobalReport/2008/.