Am Fam Physician. 1999;60(7):2126-2127
Recommendations for postexposure prophylaxis for human immunodeficiency virus (HIV) may vary, depending on the nature of the exposure. Zidovudine has been shown to be effective at reducing the risk of seroconversion among health care workers following occupational exposure. However, the effectiveness of prophylaxis following sexual assault or drug exposure is relatively unknown. Exposure during a sexual assault may be analogous to exposure on the job in that the event is usually defined as limited and nonconsensual. The Centers for Disease Control and Prevention (CDC) recommends postexposure prophylaxis for victims of sexual assault, even though its efficacy is unknown. Bamberger and colleagues propose a reasonable protocol to follow in cases of sexual assault.
Even though the relative risk of HIV transmission following a sexual assault is unknown, given the traumatic nature of rape and the prevalence of sexually transmitted diseases that develop in victims of rape, the risk may be higher than in consensual unprotected intercourse. In addition, the HIV status of the assailant is rarely known, confounding the problem even more. Studies have shown that vaginal washings may contain HIV antibodies after intercourse, but this is too unreliable a method on which to base a decision for or against prophylaxis. Consequently, prophylaxis should be offered to all victims of sexual assault, unless the HIV status of the assailant is certain to be negative.
Counseling about the risks of HIV transmission is mandatory for all victims of sexual assault. At this time, patients should be encouraged to begin HIV prophylaxis as soon as possible, certainly within 72 hours of the assault. For specific treatment protocols and a proposed testing schedule for postexposure prophylaxis, see the accompanying table. Treatment for common sexually transmitted diseases should also be initiated, as well as immunization for hepatitis B. Emergency contraception should also be discussed. A baseline HIV antibody test is useful and should be repeated at six weeks, three months and six months after the assault.
|Treatment regimen (28 days)|
|Zidovudine, 300 mg twice daily or 200 mg three times daily|
|Lamivudine, 150 mg twice daily|
|Alternative regimen (28 days)|
|Didanosine, 200 mg twice daily|
|Stavudine, 40 mg twice daily|
|Nelfinavir, 750 mg three times daily|
|Indinavir, 800 mg three times daily|
|Testing of victim|
|HIV antibody test (repeat at 6 weeks, 3 months and 6 months)|
|Hepatitis B virus antibody test|
|Gonorrhea, Chlamydia and syphilis tests|
|Wet mount for trichomonas|
|Pregnancy test (if appropriate)|
|Hepatic enzyme levels (repeat as clinically indicated)|
|Complete blood count (repeat as clinically indicated)|
The authors conclude that postexposure prophylaxis should be offered to sexually assaulted children (over 12 years of age without parental consent, under 12 years of age after a discussion with a parent). However, appropriate treatment regimens for children should be determined in conjunction with a pediatric HIV specialist. Incarcerated men who are victims of sexual assault should also be offered prophylaxis. The authors agree with CDC recommendations that all victims of sexual assault be offered postexposure prophylaxis against HIV. Further studies are needed to determine the risks of infection after sexual assault and the benefits of prophylaxis.