Discrete storm impacts on the loading of Salmonella and campylobacters within a south Georgia rural watershed

Abstract

Salmonella and campylobacters are among the top enteric food and waterborne disease causing organisms in the United States. The Georgia South Health District 8-1 in the South Georgia coastal plain, spanned by the Little River Watershed (LRW), consistently reports among the highest salmonellosis rates in the state and country along with high levels of campylobacteriosis infections. Environmental transmission, possibly from surface waters, is suspected in many cases, given the sporadic and seasonal nature of reported outbreaks coupled with no identified contaminated food source. A previous study in the watershed demonstrated a significant relationship between increased precipitation and increased levels of Salmonella and fecal contamination. In this study, we investigated whether storms are in fact significant drivers in microbial contamination of environmental waters. Higher bacterial levels were observed during storm events compared to baseline events in both pathogens studied; Salmonella levels and serotype variation were higher (p = 0.007 and p = 0.006); as were campylobacter levels (p < 0.001). We demonstrate that these organisms are ubiquitous in environmental waters, can persist under harsh conditions, including drought, and finally, increased microbial contamination of surface waters follow storm events.