Acquired immune deficiency syndrome
The riskiest sexual behavior is receiving unprotected anal intercourse. The least risky sexual behavior is receiving oral sex. There is some risk of HIV transmission when performing oral sex on a man, but this is less risky than unprotected vaginal intercourse. Female-to-male transmission of the virus is much less likely than male-to-female transmission. Performing oral sex on a woman who does not have her period has a low risk of transmission.
HIV-positive patients who are taking antiretroviral medications are less likely to transmit the virus. For example, pregnant women who are on effective treatment at the time of delivery, and who have undetectable viral loads, give HIV to their baby less than 1% of the time, compared with 13% to 40% of the time if medications are not used.
The U.S. blood supply is among the safest in the world. Nearly all people infected with HIV through blood transfusions received those transfusions before 1985, the year HIV testing began for all donated blood.
If you believe you have been exposed to HIV, seek medical attention IMMEDIATELY. There is some evidence that an immediate course of antiviral drugs can reduce the chances that you will be infected. This is called post-exposure prophylaxis (PEP), and it has been used to prevent transmission in health care workers injured by needlesticks.
There is less information available about how effective PEP is for people exposed to HIV through sexual activity or injection drug use, but it appears to be effective. If you believe you have been exposed, discuss the possibility with a knowledgeable specialist (check local AIDS organizations for the latest information) as soon as possible. Anyone who has been sexually assaulted should consider the potential risks and benefits of PEP.
Del Rio C, Curran JW. Epidemiology and prevention of acquired immunodeficiency syndrome and human immunodeficiency virus infection. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 118.
Piot P. Human immunodeficiency virus infection and acquired immunodeficiency syndrome: A global overview. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadlelphia, Pa: Saunders Elsevier; 2007:chap 407.
Sterling TR, Chaisson RE. General clinical manifestations of human immunodeficiency virus infection (including the acute retroviral syndrome and oral, cutaneous, renal, ocular, metabolic, and cardiac diseases). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 121.
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