Hepatitis in clinical laboratories: a three-year survey.

In a survey of laboratories where members of the Association of Clinical Pathologists worked, hepatitis was reported from 5 percent of 244 in 1970, 7 percent of 215 in 1971, and 2 percent of 337 in 1972. Of the 36 laboratories reporting hepatitis, a modest excess tested specimens from haemodialysis, transplant, and haemophilia units and performed tests for HB Ag. The average annual attack rate for staff of all types was 111 per 100,000 with higher rates for biochemists (268 in science graduates and 204 in technicians) and medical haematologists (258). Tests for HB Ag were positive in 17 cases ans negative in 15; nine were untested. No case was fatal and only 10 of the 41 required admission to hospital. Fourteen had a history of contract with 'high-risk (haemodialysis) specimens' but the most frequently suspected source of infection was personal contact with jaundiced or HB Ag-positive individuals and only in three cases were laboratory accidents suggested as the suspected source of infection. The findings indicate a need for caution and sensible safety precautions but not for exaggerated alarm.