Prevention of HIV/AIDS

ABSTRACT

The prevention of HIV infection is based on strategies that interrupt sexual, blood-borne, and perinatal transmission of the virus. Post-exposure prophylaxis using anti-retroviral therapy is recommended in case of mucosa or injured skin when exposed to blood, semen, vaginal/anal secretion, breast milk, or body fluid containing visible blood within no more than 72 hours. The combination of antiretroviral prophylaxis, elective caesarean delivery, and avoidance of breast feeding has reduced perinatal transmission to less than 2%. Because prophylactic chemotherapy does not guarantee perfect prevention and the adverse effects or toxicity of the drugs are considerably high, a subject who is willing to continue on with the highly risky behavior would not be a proper candidate for post-exposure prophylaxis. There is no evidence that a three-drug regimen is more likely to be effective than a two-drug regimen; however, the recommendation of a three-drug regimen is based on the assumption that the maximal suppression of viral replication will provide the best chance of preventing infection. The most frequently administered regimen is zidovudine (600 mg per day in two or three divided doses) and lamivudine (150 mg orally twice a day) for 4 weeks, with or without the addition of a protease inhibitor in selected cases.