Development of a computational model to inform environmental surveillance sampling plans forSalmonella entericaserovar Typhi in wastewater

Typhoid fever – an acute febrile disease caused by infection with the bacterium Salmonella enterica serotype Typhi ( S. Typhi) – continues to be a leading cause of global morbidity and mortality, especially in developing countries with limited access to safe drinking water and adequate sanitation. Environmental surveillance, the process of detecting and enumerating disease-causing agents in wastewater, enables estimating disease prevalence and trends within a community and is a useful tool to monitor the circulation of typhoid fever in endemic regions. This study presents a computational model, which combines dynamic and probabilistic modeling techniques, to predict – on a spatial and temporal scale – the probability of detecting S. Typhi in a wastewater system. This model may be utilized in communities to inform environmental surveillance sampling plans and may provide useful insight into selecting appropriate sampling locations and times.