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Accueil du site → Doctorat → Allemagne → 2006 → Water, sanitation, hygiene and diarrhoeal diseases in the Aral Sea area (Khorezm, Uzbekistan)

Rheinischen Friedrich-Wilhelms-Universität Bonn (2006)

Water, sanitation, hygiene and diarrhoeal diseases in the Aral Sea area (Khorezm, Uzbekistan)

Herbst Susanne

Titre : Water, sanitation, hygiene and diarrhoeal diseases in the Aral Sea area (Khorezm, Uzbekistan)

Auteur : Herbst Susanne

Université de soutenance : Rheinischen Friedrich-Wilhelms-Universität Bonn

Grade : Doctoral Thesis 2006

The Aral Sea region is a synonym for environmental disaster which is considered to cause various human health problems. However, epidemiological evidence was still lacking. The vast majority of the rural population in Khorezm district, Uzbekistan, situated on the lower Amu Darya River in the Aral Sea Basin, relies on drinking water from groundwater wells. The piped drinking water in Khorezm is mainly abstracted from surface waters. Both drinking water sources are suspected to be frequently fecally contaminated. Since the consumption of fecally polluted drinking water implies a high incidence rate of waterborne disease, it is surprising that official epidemiological data – obtained by passive monitoring – show a considerable decline in incidences of waterborne infectious diseases. This study aimed to create active monitoring data on the incidence of diarrheal diseases and to study the risk factors water, sanitation and hygiene. For the epidemiological data collection, a self-reported monitoring of diarrheal diseases was conducted during a 12-week period in summer 2003 and a 4-week winter follow-up in February 2004. Each of the 186 randomly selected households entered all diarrhea episodes on a daily basis into a diarrhea diary, which was checked and exchanged by interviewers weekly. For the determination of risk factors linked to drinking water hygiene, sanitation and hygiene a standardized questionnaire was designed with a focus on the following points : drinking water issues (collection, storage, treatment), healthrelated behavior of households, knowledge on diarrhea (causes, prevention, treatment) and domestic hygiene. Twice during the 12-week survey period, the drinking water storage vessels and the sanitation facilities of every household were checked for hygiene conditions. Forty drinking water sampling points (piped water, dug wells, tube wells, drinking water storage vessels) were monitored on a weekly basis for the fecal indicators coliform bacteria, enterococci and heterotrophic plate count bacteria during the summer follow-up. In contrast to the official data, the study does not show a peak of diarrheal diseases in July, but high, almost stable incidences were revealed for the period between May and August. Children aged under two faced the highest diarrheal disease burden with 8.4 episodes per person year. For the other age groups, the episodes per person year ranged between 2.4 and 1.7. In winter, the same age distribution was determined. The fecal contamination of the drinking water increases between May and July, but the level of the contamination is dependent on the water source. In the risk factor analysis assessed the public domain was included concerning variables on drinking water sources and kindergartens. The domestic domain of disease transmission was considered taking into account aspects such as household drinking water issues, health-related behavior, food hygiene and domestic hygiene including sanitation facilities and their maintenance as well as sewage disposal. The analysis revealed that visible contamination of drinking water during storage and absence of anal cleansing material were associated with the number of diarrhea episodes per household. Overall, the findings of the study show that the domestic domain plays a major role with regard to fecal-oral disease transmission in Khorezm. Unhealthy excreta disposal habits and unsafe drinking water storage practices have to be tackled most urgently in order to break the fecal-oral transmission route.

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Page publiée le 2 janvier 2016, mise à jour le 31 décembre 2018