Link between Diarrhea and Dengue: Fecal contamination and dengue mosquito production in household water containers in Southeast Asia

Water-related diseases are on the global public health agenda. Integration of control strategies of such diseases can be both effective and cost-efficient. Diarrheal diseases and dengue fever are major global health problems. Household water storage can be a determinant of both diseases if water, , especially for consumption, is contaminated and storage containers provide breeding sites for dengue mosquitoes. The aim of this project was to assess the associated health risks of these diseases by identifying relationships between household water management, drinking water contamination, and dengue mosquito (Aedes aegypti) production in suburban and rural communities in Thailand and Laos. Two PhD students were trained. Results so far show that 1) Entomological indices in the study sites were high, indicating a high risk for dengue transmission; 2) About 40% of point of use drinking water containers were contaminated with E. coli, with higher contamination levels in Laos than in Thailand; 3) The key Ae. aegypti breeding containers were cement tanks in toilets used for washing, bathing, and laundry; 4) Significantly more Ae. aegypti pupae were produced in E. coli contaminated containers than in uncontaminated containers; and 5) Significantly fewer bacterial taxa and a different bacterial composition were found in Ae. aegypti larvae than in the water from household containers. These conditions suggest a functional relationship between dengue and diarrheal disease. The different risk factors and disease outcomes are currently being analyzed to give a better understanding of the underlying relationships between both diseases. Project results will provide new insights that can be exploited for development of cost-efficient integrated control strategies. The project outcomes are valuable to public health institutions in decision-making processes of dengue and diarrhea control programs and will be of importance in the United Nations post-2015 development agenda.

Diarrheal diseases and dengue fever are major global health problems resulting in millions of deaths every year and billions of people live in risk areas. In the Southeast Asian region both diseases are prevalent and infection rates are high. In communiti es where provision of clean water is inadequate, storage of water for domestic use is crucial. Fecal contamination of stored water is a common source of diarrhea. Stored water is also a potential breeding site for dengue mosquitoes. Little is known of the role of stored household water for the dual risk of diarrhea and dengue. The aim of this interdisciplinary project is to assess health risks associated with household water storage by identifying relationships between household water management, contam inated drinking water, and mosquito production in household water containers. The project will identify water management practices and key vector producing container types, quantify fecal contamination and its effect on mosquito production. Results will a ssist in development of integrated disease control strategies appropriate for the Southeast Asian region. The expected outputs of the project are: 1) household water management practices in selected study communities identified; 2) Key container types i dentified from which the majority of Aedes aegypti emerge; 3) Total coliforms and E. coli detected and quantified in water stored in domestic containers; and 4) Relationship between coliform contamination of drinking water and mosquito production in house hold storage containers identified and quantified.