Long-term survival of hepatitis A virus and poliovirus type 1 in mineral water

Abstract

The survival in mineral water of hepatitis A virus (HAV) and poliovirus type 1 was compared, under controlled experimental conditions, at 4 degrees C and room temperature. Viral infectivity titers were determined by cell culture titration, while HAV antigenicity was monitored by radioimmunoassay-endpoint titration. Both viruses persisted longest at 4 degrees C. At this temperature, after 1 year of exposure, the inactivation of either HAV or poliovirus type 1 was not important. At room temperature, poliovirus type 1 was not detected after 300 days, whereas HAV was still infectious. For both temperatures, the computed regression coefficients of best-fit lines for inactivation rates for the two viruses were significantly different. The survival of HAV was also studied at 4 degrees C and room temperature in mineral water with 5- and 50-micrograms/ml protein concentrations (i.e., purity of the virus suspension) for 120 days. As shown by a comparison of the regression coefficients for the inactivation rates, the stability of HAV in mineral water depends on protein concentration and temperature. Radioimmunoassay-endpoint titration results showed inactivation patterns similar to those of cell culture titration, with the most significant reduction in HAV antigenicity at room temperature. At the two temperatures, the infectivity of HAV declined at a faster rate than the antigenicity.