has the Safe Water System been used?
and Gamble Company
families living in squatter settlements in Karachi
the impact of the SWS on diarrheal disease incidence
which etiologic agents the SWS prevents Identify modifications necessary to adapt
SWS to Pakistan’s context
as a demonstration project to use to attract funding for broader SWS intervention
in the country.
available, commercial sodium hypochlorite disinfectant
CDC safe water storage vessel
of Project Evaluation
inexpensive home-based water storage and decontamination system to improve drinking
water quality in a low-income neighborhood of Karachi was pilot tested. Forty-seven
households received a 20-liter plastic
water storage vessel with a narrow neck, lid, and high-quality spout to prevent
recontamination and a regular supply of diluted hypochlorite solution in 10 ml
single-use bottles. Household members were instructed to fill the vessel with
water, add one bottle of dilute hypochlorite, and use the water for drinking.
Twenty-fivecontrol households were recruited. Water samples were evaluated at
baseline and in unannounced follow-up visits 1,3, 6 and 10 weeks later. Baseline
drinking water samples among households who received the vessel were contaminated
with a mean 9397
cfu/100 ml of thermotolerant coliforms compared with a mean 10,990 cfu/100 ml
among controls. After intervention there was a mean 99.8% reduction in concentration
of thermotolerant coliforms in drinking water samples among the vessel households,
compared with an 8% reduction in controls. All 47 households who received the
vessel reported liking it. In a highly contaminated environment, a specifically
designed water storage container and in-home water chlorination was acceptable
to the community and markedly improved water quality.
study currently in the field is evaluating the effect of the SWS on diarrhea incidence.