Risk of hepatitis C virus infection in a population exposed to biological materials.

OBJECTIVES: The seroprevalence of hepatitis A virus antibodies was investigated in a population of 1051 subjects, of whom 376 were controls and 675 were exposed to different degrees of biological risk. METHODS: The exposed group was subdivided into subjects at low (242), intermediate (265), and high (168) biological hazard; all subjects were employed in the biomedical field. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were also determined. RESULTS: The seroprevalence of positive hepatitis A antibodies was 44.9% in all subjects but was significantly higher in males (50.6%) than in females (34.2%) and increased according to age (25.9% in subjects aged < or =40 years and 62.2% in subjects aged >40 years). No difference related to exposure to the biological risk was observed. The prevalence of transaminases at levels above normal values (chi2 = 4.079, P<0.05 for AST and chi2 = 4.806, P<0.05 for ALT) and mean values (AST P<0.05; ALT P<0.001) appeared significant in hepatitis A virus-positive subjects. On the other hand, excluding individuals with positive hepatitis C virus antibodies (16) and positive hepatitis B virus surface antigen (12), a prevalence of transaminase alterations was not observed, but mean levels of ALT lasted significantly longer in subjects with positive hepatitis A virus antibodies (P<0.01). CONCLUSIONS: The results confirm that hepatitis A virus is not a risk for employees in the biomedical field, but the presence of hepatitis A virus antibodies suggests a possible, though not clinically evident, liver involvement.