To improve the quality of life in squatter settlements, the Zonal Improvement Program (ZIP), which aims to provide direct water connection and a private toilet to every housing unit, has been implemented in Metro Manila, Republic of the Philippines, since 1985. To estimate the impact of the program, particularly the improvement of the water supply, on diarrheal incidence among under-five-year-old children, a comparative survey between a ZIP area and a non-ZIP area was conducted. A significantly higher diarrheal incidence among under-five-year-old children was observed in the non-ZIP area. This may be attributed to the increase in water consumption as a result of the improvement of the water supply in the ZIP area. The Relative Risk (RR) of water consumption with diarrheal incidence was 2.67, indicating a positive association. A water supply that provides for consumption of 60 (lpcd) could be a possible appropriate measure to reduce diarrheal cases.
Keywords: Philippines; Urban slum/squatter; diarrheal incidence; water consumption; water supply.