title: Seasonality of water quality and diarrheal disease counts in urban and rural settings in south India.
abstract: The study examined relationships among meteorological parameters, water quality and diarrheal disease counts in two urban and three rural sites in Tamil Nadu, India. Disease surveillance was conducted between August 2010 and March 2012; concurrently water samples from street-level taps in piped distribution systems and from household storage containers were tested for pH, nitrate, total dissolved solids, and total and fecal coliforms. Methodological advances in data collection (concurrent prospective disease surveillance and environmental monitoring) and analysis (preserving temporality within the data through time series analysis) were used to quantify independent effects of meteorological conditions and water quality on diarrheal risk. The utility of a local calendar in communicating seasonality is also presented. Piped distribution systems in the study area showed high seasonal fluctuations in water quality. Higher ambient temperature decreased and higher rainfall increased diarrheal risk with temperature being the predominant factor in urban and rainfall in rural sites. Associations with microbial contamination were inconsistent; however, disease risk in the urban sites increased with higher median household total coliform concentrations. Understanding seasonal patterns in health outcomes and their temporal links to environmental exposures may lead to improvements in prospective environmental and disease surveillance tailored to addressing public health problems.
authors: Department of Civil and Environmental Engineering, Tufts University, Medford, MA, USA.
authors: Alexandra V
authors: AV
authors: Kulinkina
authors: Department of Community Health, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Venkat R
authors: VR
authors: Mohan
authors: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Mark R
authors: MR
authors: Francis
authors: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Deepthi
authors: D
authors: Kattula
authors: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Rajiv
authors: R
authors: Sarkar
authors: Department of Civil and Environmental Engineering, Worcester Polytechnic Institute, Worcester, MA, USA.
authors: Jeanine D
authors: JD
authors: Plummer
authors: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.|Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, USA.
authors: Honorine
authors: H
authors: Ward
authors: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Gagandeep
authors: G
authors: Kang
authors: Department of Community Health, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Vinohar
authors: V
authors: Balraj
authors: Department of Civil and Environmental Engineering, Tufts University, Medford, MA, USA.|Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Elena N
authors: EN
authors: Naumova
mesh_terms: D003967:Diarrhea / Q000453:epidemiology*; D005843:Geography; D006801:Humans; D007194:India / Q000453:epidemiology; D011891:Rain; D012044:Regression Analysis; D012306:Risk; D012424:Rural Population / Q000706:statistics & numerical data*; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D014505:Urban Population / Q000706:statistics & numerical data*; D060753:Water Quality