Faecal contamination of water and fingertip-rinses as a method for evaluating the effect of low-cost water supply and sanitation activities on faeco-oral disease transmission. I. A case study in rural north-east Thailand.

Most villagers in north-east Thailand carry water to their homes and store it in separate containers depending on its subsequent use. In one village, information on water use was collated with the bacteriological quality of stored water, water sources and fingertip-rinses. Stored water quality was a function of water-related activities rather than quality at source (P less than 0.0001). Specifically water used for toilet, washing dishes and cooking-related activities was much more contaminated with faecal bacteria than that used for drinking and cooking. Salmonella spp. was significantly more common in water used for washing dishes than drinking (P less than 0.05). Escherichia coli contamination of fingertip-rinses was strongly associated with the individual's activity prior to testing (P less than 0.0001); child care, food and water-related activities produced much higher levels of fingertip contamination than others. Dirty utensils used for cooking and eating were usually left to soak and faecal bacterial growth occurred in this grossly contaminated soak-water. Cross-contamination via water handling was the main mechanism of stored water pollution. These results were used to develop a hygiene intervention study presented in a companion paper.