Changing seasons and diarrhoeal diseases

Access to safe drinking water and diarrhoeal diseases in India

Although as high as 82.7 % rural and 91.4 % urban populations have access to safe drinking water in India according to the Census 2011, this does not provide assurance of adequate quality along with equitable distribution of water. The paper 'Seasonality of water quality and diarrhoeal disease counts in urban and rural settings in south India' published in the journal Scientific Reports informs that a high number of Indians are affected by waterborne diseases and deaths among children due to diarrhoeal diseases are common due to poor water quality, which seems to be affected by seasonality. However, it is difficult to determine the association between water quality, seasonal changes and diarrhoea due to multiple levels of exposure and weak associations between current water quality indicators and disease causing organisms. 

Seasonal patterns of self reported diarrhoeal diseases and water quality

The paper discusses the findings of a study that examined the association between seasonal patterns of self reported diarrhoeal disease episodes and water quality in public (street taps) and private (household water storage containers) sources in two urban and three rural sites in Vellore District, Tamil Nadu, India. 

The urban sites obtained water from shared a common well located near a dry river bed, which was provided through a public tap system managed by the Vellore Municipal Corporation (VMC). Rural areas depended on public piped water systems and water was drawn from their own wells making water available for several hours in the morning.

Findings of the study

• Although heavy microbiological contamination was common across time, urban and rural sites and in water sources, seasonal increases were observed.
• Total Coliform concentrations in the piped water supplies in both urban and rural areas were the highest during the wet seasons, while were the lowest during high heat in the summer seasons.
• Piped water was found to have high bacterial contamination due to infiltration of fecal contamination from the environment, which was more likely to occur during periods of heavy rain.
• Higher temperatures decreased and higher rainfall increased diarrhoeal risk with temperature being the predominant factor in urban and rainfall in rural sites.

The study confirmed the associations among diarrhoeal diseases, water quality and changing seasons and that they could vary  by urban and rural settings. The paper ends by arguing that a better understanding of the seasonal patterns influencing environmental exposures, health outcomes, and their links to local meteorological features can greatly help:

• In planning interventions designed to control diarrhoeal diseases.
• In making improvements in routine water quality monitoring integrated with waterborne disease surveillance to quantify and improve the impact of water infrastructure on health.
• Benefit communities through planning of targeted educational campaigns on safe water storage practices, particularly during hot and dry seasons.

A copy of the paper can be downloaded from below: