Occupational HIV infection and health care workers in the tropics

Abstract

A literature review revealed 33 reports of health care workers who have contracted HIV infection as a result of their work. Four of these were expatriate doctors who had worked in Africa. The commonest mode of transmission was needlestick injury, but several infections acquired through contact or skin or mucous membrane with infected blood have been reported. In this paper we outline how the risk of HIV infection in a health care worker can be estimated for a given number of exposures. The formula is based on the known likelihood of transmission per needlestick, the seroprevalence rate among patients, and the number of needlestick injuries that occur. We also suggest a list of measures by which the risk of HIV transmission to hospital staff can be minimized.

PIP: 4 physicians in the Netherlands conducted a literature search using Index Medicus '89 and Medline '89 to learn of incidents of HIV transmission to health care workers (HCWs). As of February 1989, 19 documented seroconversions occurred in HCWs with needle stick injuries responsible for 15 seroconversions. Exposure to nonintact skin, mucous membranes, or HIV contaminated blood caused the remaining 4 seroconversions. Further, there were 15 presumptive seroconversions with all 13 HCWs exposed to the blood of infected patients. Physicians comprised 6 of the presumptive infections and 4 were in Africa when they were exposed to HIV. The incidence of accidental needle stick injuries during an operation reported in 2 articles ranged from 1.5-5.6%. Other researchers revealed that a correlation exists between the number of such injuries and experience of the surgeon. For example, head surgeons in a hospital in Saudi Arabia experienced needle stick injuries in 4% of all operations whereas assistant surgeons experienced then in 12% of all operations. 1 report showed that the number of needle stick injuries during an average contract of 3.6 years for 406 Dutch HCWs in Africa varied from 0-300 (mean 9.1; median 2) with physicians receiving the highest (mean 15; median 5) and nurses the lowest (mean 3.4; median 0). Researchers have estimated the mean seroconversion rate after an injury by a hollow needle contaminated with HIV to be .49%. The rate is probably lower is a solid needle was used and if the patient was asymptomatic. The cumulative risk of seroconversion due to needle stick injuries is associated to HIV prevalence in the population. HCWs should consider all patients to be HIV positive so preventive procedures should always be practiced, such as using sharp needles, never recapping needles, and wearing gloves.