Prevalence of hepatitis B among school dental nurses

A survey of hepatitis B serological markers and associated risk factors was carried out among school dental nurses in 1985. A postal questionnaire provided information on demography, years worked and residential history from birth to 10 years of age. A blood sample was provided by 1015 subjects (95% response). All sera were tested for HBsAg, anti-HBs and anti-HBc, and HBsAg positive sera for HBeAg and anti-HBe. Twenty-three percent of subjects were both anti-HBs and anti-HBc positive, 2% were anti-HBs positive and 3% anti-HBc positive only. Less than 1% were HBsAg positive. Prevalence varied with geographic area--40% in the north and east of the North Island, 25% in the south and west of the North Island and 5% in the South Island. There was a linear increase in marker prevalence with age group in subjects under 45 years. Only in the north and east of the North Island was there a relationship (inverse) between the proportion of Europeans treated and marker prevalence. Childhood residence had little effect on prevalence (p less than 0.001). The results suggest that infection occurred during adult life, whether as a result of occupation or area of residence cannot be determined without a control group.