02423nas a2200301   4500000000100000008004100001653001700042653001300059653002000072653001500092653003500107653001100142653002400153653001900177653001300196653002500209653001500234100001400249700001500263700001400278700001200292245014500304856005700449300001100506490000700517520158300524022001402107       1991                            d10aWater Supply10aTrachoma10aschistosomiasis10aSanitation10aIntestinal Diseases, Parasitic10aHumans10aHookworm Infections10aDracunculiasis10aDiarrhea10aDeveloping countries10aAscariasis1 aEsrey S A1 aPotash J B1 aRoberts L1 aShiff C00aEffects of improved water supply and sanitation on ascariasis, diarrhoea, dracunculiasis, hookworm infection, schistosomiasis, and trachoma.  uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2393264/  a609-210 v693 a<p>A total of 144 studies were analysed to examine the impact of improved water supply and sanitation facilities on ascariasis, diarrhoea, dracunculiasis, hookworm infection, schistosomiasis, and trachoma. These diseases were selected because they are widespread and illustrate the variety of mechanisms through which improved water and sanitation can protect people. Disease-specific median reduction levels were calculated for all studies, and separately for the more methodologically rigorous ones. For the latter studies, the median reduction in morbidity for diarrhoea, trachoma, and ascariasis induced by water supplies and/or sanitation was 26%, 27%, and 29%, respectively; the median reduction for schistosomiasis and dracunculiasis was higher, at 77% and 78%, respectively. All studies of hookworm infection were flawed apart from one, which reported a 4% reduction in incidence. For hookworm infection, ascariasis, and schistosomiasis, the reduction in disease severity, as measured in egg counts, was greater than that in incidence or prevalence. Child mortality fell by 55%, which suggests that water and sanitation have a substantial impact on child survival. Water for personal and domestic hygiene was important in reducing the rates of ascariasis, diarrhoea, schistosomiasis, and trachoma. Sanitation facilities decreased diarrhoea morbidity and mortality and the severity of hookworm infection. Better water quality reduced the incidence of dracunculiasis, but its role in diarrhoeal disease control was less important than that of sanitation and hygiene.</p>
  a0042-9686