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 communities 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, contaminated 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 assist in development of integrated disease control strategies. The expected outputs of the project are: 1) household water management practices in selected study communities identified; 2) Key container types identified 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 household storage containers identified and quantified.
Long-term goal: Increased understanding of relationship between causes of diarrheal disease and dengue fever for potential development of integrated disease control strategies.
Specific objectives (project purpose): Assess health risks associated with household water storage by identifying relationships between household water management, contaminated drinking water, and Aedes aegypti production in household water storage containers.
Approaches, hypotheses and choice of methods
A literature search reveals no studies where the two diseases have been studied together and how one affects the other. Thus, little is known of the role of stored household water for diarrhea and dengue risk. This project seeks to clarify these issues by addressing the following questions: How is household water collected, transported, stored and used? Is contaminated household water a major determinant for diarrheal infections? How does piped water and container lids affect fecal contamination and dengue mosquito production? Which preventive practices exist? Are the key container types of importance for adult Ae. aegypti emergence used as drinking water containers? Does microbially contaminated drinking water increase production of Ae. aegypti and in larger mosquitoes?
The responsibilities for control and prevention of dengue and diarrhea often lie under separate national departments with little communication or collaboration. By investigating the issues illustrated above in an integrated manner the potential for developing integrated and cost-efficient control strategies may become apparent. The interdisciplinary nature of this project, combining ecological, microbiological, socio-economic and cultural aspects will reveal potential synergies and solutions for integrated control. The project will also be an incentive to undertake similar studies in other countries under other socioeconomic and cultural conditions, thus contributing to solutions to disease problems that are of global concern.
The research hypotheses of this project are therefore:
1. Bacterial contamination of household water occurs during collection, transport, and handling of water.
2. Stored household water constitutes a significant risk for diarrheal infections.
3. Ae. aegypti commonly breeds in household drinking water containers.
4. Piped water availability reduce contamination of stored water and breeding of Ae. aegypti.
5. Covered household water containers reduce water contamination and mosquito breeding.
6. Increased microbial contamination in household drinking water containers increase production of Ae. aegypti and result in larger mosquitoes.
Both quantitative and qualitative approaches will be used to address these problems and hypotheses. The methods used here are commonly used in both diarrhea and dengue field and laboratory research. Social research methods will be used to collect information on socioeconomic status and cultural-dependent water management and health-related practices.