The major modes of transmission of HIV include sexual route, transfusion of infected blood and blood products, intravenous drug abuse and mother to child transmission. Another mode of transmission, though largely undocumented, is transmission of infection by needle stick or other sharp injury in a hospital or a health care setting. Although, avoiding occupational blood exposures is the primary means of preventing HIV transmission in health care settings, appropriate post exposure management guidelines form an important element of work place safety. These guidelines were first formulated in 1990 and were last revised by US Public Health Services in 1998. Since then, several new anti-retroviral agents have been approved by FDA, more information is available regarding use and safety of these drugs, possibility of transmission of drug resistant virus and concern has arisen about use of PEP when it is not warranted. Hence, these guidelines have been revised and published by US Public Health Service Department again in June 2001. Post-exposure prophylaxis following exposure to HIV is most commonly used after an occupational exposure but can also be used following non-occupational exposure particularly in cases of sexual assault.

Post exposure prophylaxis following occupational exposure to HIV:

Health Care Personnel (HCP) is normally at a very low risk of acquiring HIV infection during management of an HIV infected patient. However, the absence of a vaccine or effective-curative treatment following an accidental occupational exposure makes the health care personnel apprehensive. So, it is very necessary to have a comprehensive programme in place to deal with any accidental exposure to blood or body fluids of an HIV infected person.