An epidemic of gastroenteritis traced to a contaminated public water supply.

Between January 1 and March 15, 1974, approximately 1200 cases of acute gastrointestinal illness occurred in Richmond Heights, Florida, a residential community of 6500 in south Dade County. Over one-third of all families in the area had at least one member affected. The findings of 10 culture-proven cases of shigellosis among those who became ill and clinical signs and symptoms in the others suggest that most of the other cases that were not cultured may have been shigellosis also. Epidemiologic investigation showed that consumption of tap water was associated with illness in the initial cases of affected families. Evaluation of the Richmond Heights public water supply disclosed numerous inadequacies in both design and operation. One of the wells providing water to the community was continuously contaminated with excessive levels of fecal coliforms from a nearby septic tank, and a breakdown in chlorination on January 14-15 caused approximately 1 million gallons of inadequately chlorinated water from the contaminated well to be distributed to the community 48 hours before the epidemic began. Correction of deficiencies in the water plant was undertaken by the utility company; the residents of Richmond Heights were instructed to boil their drinking water or to use commercially bottled water pending completion of corrective measures. A FUll scale study is planned for all similar public water supplies in Dade County.