TY - JOUR T1 - Environmental cholera (<em>Vibrio cholerae)</em> dynamics in an estuarine system in southern coastal Ecuador JF - bioRxiv DO - 10.1101/110189 SP - 110189 AU - Sadie J. Ryan AU - Anna M. Stewart Ibarra AU - Eunice Ordóñez AU - Winnie Chu AU - Julia L. Finkelstein AU - Christine A. King AU - Luis E. Escobar AU - Christina Lupone AU - Froilan Heras AU - Erica Tauzer AU - Egan Waggoner AU - Tyler G. James AU - Washington B. Cárdenas AU - Mark Polhemus Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/02/21/110189.abstract N2 - Cholera emergence is strongly linked to local environmental and ecological context. The 1991- 2004 pandemic emerged in Perú and spread north into Ecuador’s El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in 5 months for pathogenic and non-pathogenic Vibrio cholerae, by polymerase chain reaction (PCR). We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Cholera presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera– estuarine system to anticipate potential future cholera outbreaks. ER -