Salmonellosis in Riverside, Calif.

This article discusses the details of the bacteriology of an investigation of a major waterborne outbreak of salmonellosis in humans that occurred in Riverside, California in May 1966. Engineering and laboratory studies could not determine the source of water contamination. Despite the apparent failure of the coliform test to indicate an unsafe water, it was decided not to change the coliform test. It is suggested that sampling programs should be carefully reviewed to insure maximum geographic and time distribution of regular samples. Further, an effective alarm system should be instituted for every water system to make the most effective use of laboratory information.