Assessment of the risk of infection associated with Coxsackie B viruses in drinking water

The risk of infection constituted by enteroviruses detected in drinking water supplies analysed in this study were assessed. Coxsackie B viruses (CBV) were used as a model in these assessments. A high proportion of Coxsackie B virus infections are asymptomatic. However, clinical manifestations may range from mild, undifferentiated febrile illness or upper respiratory tract infection to a severe, systemic and sometimes fatal disease of sensitive populations. Dose-response studies suggested that an exponential model best describes infectivity of CBV. The analysis of 172 samples of treated drinking water supplies described in this study revealed the presence of CBVs in 11% (water treatment unit A) and 16% (water treatment unit B) of the samples. This incidence of CBV was used as a basis for risk assessment. The results indicated that the drinking water supplies concerned constitute a risk of CBV infection of 3.91 × 10^-3 (unit A) and 7.4 × 10^-3 (unit B) per year. The estimated risk of infection are about an order of magnitude higher than the yearly acceptable risk of one infection per 10,000 consumers proposed for drinking water supplies.