Several studies (Abstract #210-215) addressed various aspects of post-exposure prophylaxis, both following occupational (#210-214) and community/sexual exposure (#214, 215). Studies reported on the tolerability and feasibility rather than the effectiveness. However, one disturbing case report (#210) detailed HIV sero-conversion despite 4-drug treatment (AZT, 3TC, DDI, and IDV) following occupational exposure in a nurse who sustained a needle stick. In this report, the nurse sustained the injury with a 21-gauge butterfly from a source case with an HIV viral load of 1540 and CD4 count of 480. The source case was receiving AZT/3TC and had previously received D4T. He also was infected with HCV, which apparently was also transmitted with the injury. After 6 weeks, the nurse discontinued PEP; one month later, she developed acute symptomatic HIV, with a viral load of >750,000. To date, treatment has resulted in containment of viral load (now undetectable), but a gradual decline of her CD4/CD4 ratio has occurred. This represents the first case of PI failure in PEP.

Other, more optimistic reports demonstrated the feasibility of a national PEP Hotline, PEPLine (phone # 888-448-4911) (#211). In this report, data from 5500 calls was reported, two-thirds of which were from percutaneous exposures. One third of the calls came from the exposed HCW, the other from providers. PEP was recommended in 56% of exposures, generally for 2-drug treatment. Rates of tolerance of 3-drug PEP (21.6% stopped due to side effects) and 2-drug PEP (10.4% stopped) in Italy (poster #212) were comparable to US rates. In a similar system in Canada, community exposures, community needle use, or sexual assault accounted for 25% of all calls (#214). And in San Francisco, a new program offering PEP and counseling for community exposures appeared feasible. Thus far, 328 persons had been screened, and 79% of those who began treatment finished a 4-week course, similar to completion rates in HCW's (#215).

These studies suggest that PEP is feasible in hospitals and the community and that more than three-fourths of persons can finish the regimen. The efficacy of PI-containing regimens remains to be established as the single disturbing report (210) reminds us.