What is the risk of HIV post exposure?

A 24 yo male presents to the ED saying that he had receptive anal intercourse without the use of a condom with an male partner who was known to have had sex with other men. He is also worried because many years ago she was not treated for a needlestick injury. TRUE statements about postexposure prophylaxis (PEP) for HIV include which of the following?
 (Choose three answers.)

A. A case-control study in 1997 demonstrated that health care workers who received AZT after needlestick exposures were 81% less likely to undergo seroconversion to positivity for HIV.
B. The use of PEP does not assume that the person who was exposed to HIV is HIV negative.
C. The overall rate of HIV transmission through percutaneous inoculation through a needle is reported to be 0.3%.
D. The estimated risk of transmission from receptive anal intercourse is 50%.
E. The estimated transmission from receptive vaginal intercourse is 0.1-10%.

…an excerpt from The Kaji Review


Answer: A, C, and E

Providing PEP assumes that the patient with the exposure is HIV negative.  A baseline negative HIV test should be documented along with PEP.   Statement A, C and E are true. The estimated risk for receptive anal intercourse is 1 – 30%. The estimated risk of transmission associated with sharing needles for injection drug use is 0.67% per needle sharing contact.  Overall risk after a needle stick is 0.3%. The generally recommended treatment is a four week dual nucleoside regimen such as zidovudine and lamivudine. However, adding a third agent such as ritonavir may improve efficacy.



Landovitz RJ, Currier JS. Postexposure prophylaxis for HIV infection. N Eng J Med. 2009 Oct 29; 361(18): 1768-75.

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