How Long Can Enteric Pathogens Survive in Polluted Environmental Media?

Monitoring pathogen survival in polluted environmental media is useful as an early warning tool to forestall outbreaks of infections and safeguard public health. Survival of clinical strains of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi and Vibrio cholerae was monitored for 192 hours in pre-sterilised samples of domestic wastewater and sediment, agricultural wastewater and river water. All pathogens rapidly proliferated in the first 72 hours in all environmental media (2-3 log order increases), but either rapidly or steadily declined thereafter, with P. aeruginosa and V. cholerae demonstrating the longest persistence and S. typhi the least. Survival kinetics of pathogens are similar in domestic wastewater and sediment, though persistence was longer in sediment. While the pathogens did not proliferate as much in agricultural wastewater as compared with the domestic wastewater and sediment, they however, persisted for a longer time in the former. Notably, river water supported the survival of pathogens for a significantly (p< 0.05) longer time than any of the wastewaters and sediment. These findings have implications in the prediction and early detection of potential pollution points during epidemiological and source tracking studies.