Spatial and seasonal dynamics of cholera (Vibrio cholera) in an estuary in southern coastal Ecuador

 

Authors
Stewart Ibarra, Anna Mar?a
Format
Article
Status
publishedVersion
Description

The emergence of waterborne diseases such as cholera, whose causative agent is pathogenic strains of Vibrio, is strongly linked to the local environmental and ecological context. Machala is a port city of 250,000 people in El Oro province, on the southern coast of Ecuador, near the Peruvian border. The 1991-2004 cholera pandemic emerged in Peru and spread north into El Oro, making it a key sentinel site for understanding dynamics in the ongoing 7th pandemic. In Machala, many peoples? livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use, making the coupled human-estuarine system an important component of public health management. We sampled five estuarine locations twice weekly over a 10-month span, within a gradient of human use, and over a geographic range from inland to ocean, to measure water-specific environmental variables such as pH, temperature, salinity, conductance, and algal concentration, and conducted PCR testing for Vibrio spp., including pathogenic strains, across 5 months. Our sites exhibited considerable seasonal and spatial heterogeneity in environmental variables, with clear peaks during specific months. We found evidence of an environmental reservoir for Vibrio spp., including pandemic strains O1 and O139, but did not confirm ongoing toxigenic presence. We found that the timing of positive PCR results was coupled to the environment. This study was conducted in a moderately normal climate year, providing a preliminary framework for monitoring coupled Vibrio ? estuarine dynamics for potential emergence of cholera outbreaks in the region. Keywords: Cholera, Ecuador, disease dynamics, GIS, waterborne pathogens, disease emergence.
https://www.researchgate.net/publication/299608520_Spatial_and_seasonal_dynamics_of_Vibrio_spp_in_an_estuary_in_southern_coastal_Ecuador

Publication Year
2016
Language
eng
Topic
SPATIAL DYNAMICS
SEASONAL DYNAMICS
VIBRIO SPP.
ECUADOR
Repository
Repositorio SENESCYT
Get full text
http://repositorio.educacionsuperior.gob.ec/handle/28000/3800
Rights
openAccess
License
restrictedAccess