Seroprevalence of hepatitis A virus infection among sewage workers in the Parisian area, France

Sewers are an ideal environment to be occupationally exposed to viral hepatitis A (HAV) infection, because of high frequency and ability of the virus to remain viable for prolonged periods in sewage. However, data on the occupational risk of HAV infection among sewage workers is not well documented. In a cross sectional study comparing sewage workers (n = 155) to those not occupationally exposed to it (n = 70), we found a non significant increase in HAV seropositivity among sewage workers of 12.9% (p = 0.07). The prevalance of HAV antibody was significantly associated with duration of occupational exposure to sewage (p < 0.015), stay in HAV endemic areas (p < 0.03), age (p < 0.001), and number of siblings (p < 0.03). A stepwise logistic regression analysis gave an adjusted odds ratio for HAV seropositivity 2.15 fold greater in sewage workers compared to those not occupationally exposed to it. So, although there was no significant difference in the prevalance of HAV antibody between sewage workers and others, exposure to sewage was an independent risk factor for HAV seropositivity, and this raises the question of whether it is necessary to vaccinate sewage workers against viral hepatitis A.