HIV Infection and Acquired Immunodeficiency Syndrome (AIDS)
Description
AIDS is a serious disease, first recognized as a distinct syndrome in 1981. 
AIDS represents the late clinical stage of infection with human immunodeficiency virus (HIV), 
which 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.

Occurrence
AIDS and HIV infection occur worldwide. The Joint United Nations Programme on 
HIV/AIDS estimates that, as of the end of 2005, nearly 40 million persons were 
living with HIV/AIDS worldwide. Although the most globally affected part of the 
world remains sub-Saharan Africa, in recent years, the steepest increases in HIV 
infection have occurred in Eastern Europe, Northern, Central, and East Asia 
(see map 4-5). Many countries lack comprehensive surveillance systems, and despite 
improvements, the true number of cases is likely greater than officially reported, 
particularly in developing countries. 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 (1) and drug-using behaviors (2).



MAP 4-05 Prevalence of HIV infection
 
Source: UNAIDS 2006 Report on the global AIDS epidemic.
http://www.unaids.org/en/HIV_data/2006GlobalReport/default.asp.

Risk for Travelers
The risk of HIV infection for international travelers is generally low. 
Factors to consider in assessing risk include the extent of direct contact with 
blood or other potentially infectious secretions and the extent of sexual contact 
with potentially infected persons. In addition, the blood supply in developing 
countries might not be adequately screened.

Prevention
No vaccine is available to prevent infection with HIV. For information on 
the safety of vaccines for HIV-infected persons see Chapter 9. Travelers should
be advised that HIV infection is preventable. HIV can be transmitted through 
sexual intercourse and needle- or syringe-sharing; by medical use of blood, 
blood components, or organ or tissue transplantation; through artificial insemination;
and 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., an airplane, an automobile, a boat, a bus, or a train)
by persons with AIDS or HIV infection does not pose a risk of infection for 
the crew members or other travelers.

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. 
Use 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.
Travelers should be advised to avoid sexual encounters with persons who are 
infected with HIV or whose HIV infection status is unknown. Travelers should 
also be advised to avoid sexual activity with persons 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. 
In countries with high rates of HIV infection, many persons without these 
risk factors may be infected and be unaware of their status. Condoms, when 
used consistently and correctly, prevent transmission of HIV. Travelers who 
engage in vaginal, anal, or oral-genital sexual contact with a person who is 
HIV-infected or whose HIV status is unknown should use a latex condom. 
Persons who are sensitive to latex should use condoms made of polyurethane or 
other synthetic materials. Some areas may have a limited supply and selection of 
condoms, or available condoms may be of inferior quality. Persons traveling to 
these areas who engage in sexual contact with persons who are HIV-infected or 
whose HIV status is unknown 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 anal, vaginal, 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, and the widely used spermicide nonoxynol-9 can increase the risk of HIV 
transmission. In many countries, needle-sharing by intravenous drug users is a major 
means of HIV transmission and transmission of other infections, such as 
hepatitis B and hepatitis C. 
Travelers should be advised not to use drugs intravenously or share needles 
for any purpose (3). 
Travelers should also be advised to avoid, if at all possible, receiving medications 
from multidose vials, which may have become contaminated by used needles.

In many developed countries (e.g., Australia, Canada, Japan, New Zealand, western 
European nations, United States), the risk of transfusion-associated HIV infection 
has been virtually eliminated through required testing of all donated blood for 
antibody to HIV. In the United States, donations of blood and plasma must be 
screened for HIV-1 and HIV-2 antibodies, the HIV-1 p24 antigen, and traces of 
HIV genetic material that may indicate infection. Developing countries may have 
no formal program for testing blood or biological products for contamination with 
HIV. In those countries, travelers should (when medically prudent) avoid use of 
unscreened blood-clotting factor concentrates or concentrates of uncertain purity. 
If transfusion is necessary, the blood should be tested, if at all possible, for 
HIV antibody by appropriately trained laboratory technicians using a reliable test.

Needles used to draw blood or administer injections should be sterile, single use, 
disposable, and prepackaged in a sealed container. Travelers with insulin-dependent 
diabetes, hemophilia, or other conditions that necessitate routine or frequent 
injections should be advised to carry a supply of 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.

Occasionally, an overseas traveler?s duties may involve the need to handle blood products 
(e.g., nurse volunteer drawing blood or medical missionary performing surgeries) 
or other potentially infectious materials (e.g., research scientist preparing human 
tissue samples). Persons who may have contact with HIV-infected biological materials 
should ensure that they will have access to all appropriate personal protective 
equipment necessary (e.g., latex gloves, goggles, face shield, gowns) and that this 
equipment meets established international quality standards. Such affected travelers 
may also wish to consider familiarizing themselves with the principles of postexposure 
prophylaxis and, in the event of a high-risk exposure were to occur, 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 (4). 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 (5).

International travelers should be advised that some countries screen incoming travelers 
for HIV infection and may deny entry to persons with AIDS and 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. An unofficial list 
compiled by the U.S. Department of State can be found at the following 
URL: http://travel.state.gov/travel/tips/brochures/brochures_1230.html.

References

Memish ZA, Osoba AO. Sexually transmitted diseases and travel. Int J 
Antimicrob Agents. 2003;21:131-4.
Wright ER. Travel, tourism, and HIV risk among older adults. 
J Acquir Immune Defic Syndr. 2003;33(suppl. 2):S233-7.
CDC. HIV Prevention Bulletin: Medical Advice for Persons who Inject Illicit Drugs. 
Available at: http://www.cdc.gov/idu/pubs/hiv_prev.htm. Accessed May 31, 2006.
CDC. Updated U.S. Public Health Service guidelines for the management of 
occupational exposures to 
HIV and recommendations for post-exposure prophylaxis. MMWR Recomm 
Rep. 2005;54 (RR-9):1-11.
CDC. Management of possible sexual, injecting-drug-use, or other 
nonoccupational exposure to HIV, 
including considerations related to antiretroviral therapy. 
MMWR Recomm Rep. 1998;47(RR-17):1-19.




JOHN T. BROOKS