Combating Cholera Caused by Climate Change in Bangladesh

Project summary

Bangladesh (Bg) is one of the most hazard prone countries in the world and is expected to be one of the worst affected by Climate Change (CC). Every year, extreme weather events such as flooding, droughts and cyclones have devastating effects, also impacting on water quality and quantity and sanitation infrastructure. As extreme weather events continue to increase with CC, Bg faces a multitude of adverse health, economic, and livelihood consequences.

Among the projected adverse  CC effects in Bg are altered patterns of cholera transmission. Cholera has been endemic in Bg for more than 2000 years and is associated with water and sanitation as well as a number of environmental factors. Consequently, cholera incidence is expected to rise from both environmental responses to CC and less water availability for households.

However, our understanding on how CC impact on cholera and how to mitigate is incomplete. Focusing on water quantity and hygiene, this proposal will apply a new innovative multi-disciplinary methodology to understand CC influence on cholera by identifying the relative risk based on environmental, behavioural, and water resource management factors. We will further investigate community adaptive capacities have in reducing their risk of cholera; how the risk patterns change due to extreme weather events, and how this can help to increase people’s resilience to lessen the burden of the disease both in Bg and other voulnerable areas in low-income countries.

Outputs

Project Completion Report

C5 has identified a variety of new, known, and forgotten transmission routes of Vibrio cholerae and E.coli, such as kitchen utensils, fish, flies, fomites, boiled drinking water, and person-to-person transmission. Together, the results show that the kitchen environment constitutes a grave health risk, especially in low-income households where hygiene is compromised due to limited domestic water access (water stress). Further, C5 data showed that food could be responsible for 95% of a person’s total daily intake of E.coli in a Dhaka slum and that 80% of E.coli found in drinking water could have an animal origin, thus not linked to human-associated fecal contamination. It is, however, unknown how the transmission routes identified by the C5 will change under different Climate Change water stress conditions. C5 added to the discussion of the Vibrio Cholera transmission from the reservoir in the Bay of Bengal to Dhaka. First, by showing that people simply do not drink the river water due to salinity and second, that people prefer to use the same type of water source (well) during floods, not by using the flooded well, but by walking a longer distance to an unpolluted well, thereby decreasing the quantity of water used by the household.
To describe some of the possible drivers behind the Climate Change discourse in Bangladesh, C5 invented the new term Climatization [35] to describe when Climate Change is used as a cover-up for underlying structural failures.
To validate different scientific methodologies, various studies were done: climate and cholera modeling, defining cholera and diarrhea, water quantity measurements, a mobile phone disease monitoring system “The Choleraphone”, and various microbiological methods. Interestingly, the C5 put a price on non-severe (non-hospital needed) diarrhea which was equivalent to one day of salary for a poor household per diarrhea episode.