Temporal and spatial analysis of associations between meteorological factors, water quality and enteric infections in urban and rural communities in southern India

There is growing evidence confirming the utility of meteorological parameters to enhance forecasting and characterize the risk of enteric infections. This research conducted in partnership with the Christian Medical College (CMC) in Vellore, India aims to determine environmental parameters influencing the rate of enteric infections in three rural villages and two urban slums. 2287 water samples from public taps and households were collected regularly over a 12-month period. Daily meteorological data were obtained from a regional station. Harmonic regression models (HRM) adapted to time series data and implemented in R statistical software were used to assess the temporal pattern in enteric infections with respect to seasonal fluctuations in water quality (WQ), ambient temperature, precipitation, and relative humidity. The spatial relationships between household and tap WQ were assessed using Geographical Information Systems (GIS). Total dissolved solids and coliform exhibited significant seasonal patterns after accounting for meteorological parameters. HRM describe up to 54% variability in temporal behavior of enteric infections (seasonality accounting for 6-30%) with a seasonal peak in diarrhea occurred between mid-February and mid-April. Differences in seasonality for WQ between rural and urban settings were noted. Identifying and characterizing the time periods and locations associated with high risk of exposure to pathogens may allow for more specific targeting of water quality monitoring efforts and intervention strategies. This research demonstrates the utility to routinely collected meteorological and WQ data in identifying environmental risk indicators, particularly useful in resource poor areas and locations with complex water provision schemes.