Frequency of nosocomial transmission of HIV infection among health care workers [letter].

Documented HIV seroconversion in health care workers from patient contact has occurred. The risk of HIV seroconversion from a single needle-stick accident from an infected patient has been shown to be about 0.35% on the basis of composite analysis of 8 seroprevalence studies. Needle-stick injury is the most important risk for health care workers occurring quite commonly. The frequency of injuries in workers caring for HIV infected patients in our hospital has declined from 4.6 needle-sticks/1000 HIV infected patient-days in 1984 to 1.9/1000 days from 1/1/86 to 6/30/87. The probability of nosocomial transmission of HIV in our institution can be calculated. 105000 HIV infected patient-days would yield a 50% chance of at least 1 case of HIV transmission to a health care worker. This number of patient days will be exceeded in many large urban medical centers over the next 4 years. Many institutions are likely to have to face the prospect of nosocomial transmission to a member of their staff in the next few years. Prevention of needle-stick injuries is a critical factor in avoiding this outcome.