Quantitative assessment of the inactivation of pathogenic and indicator viruses in natural water sources

Suitable monitoring of drinking water sources may prevent the occurrence of waterborne disease. Furthermore, determining the environmental factors which affect virus inactivation may help in predicting the fate of pathogenic microorganisms in water sources. This study was conducted to evaluate the suitability of F+ bacteriophages as indicators for microbial contamination of water sources and to determine the effects of water quality, temperature and virus type on virus inactivation. The inactivation of hepatitis A virus (HAV), poliovirus 1, F+ bacteriophages and E. coli was compared in groundwater and wastewater effluents at various temperatures. Similar inactivation patterns were observed for HAV and poliovirus 1 under various experimental conditions. Male-specific bacteriophages persisted for the longest time in the various water types, whereas E. coli inactivation was the fastest in groundwater at 4 and 37°C. F+ bacteriophages have been found more suitable than E. coli to predict the inactivation of pathogenic viruses in natural water sources. The effects of temperature and microorganism type have been found significant in all studied water types. The interaction between temperature and microorganism type was highly significant in groundwater and phosphate buffered saline and less significant in raw wastewater, indicating that wastewater may enhance virus persistence. The difference between the inactivation of F+ bacteriophages and E. coli was significant under all experimental conditions, indicating their suitability to signal the persistence of pathogenic viruses in natural water sources.