Critical control points for foods prepared in households whose members had either alleged typhoid fever or diarrhea.

Hazard analysis of food preparation practices were conducted in four households and eleven others were visited to survey both food preparation practices and environmental conditions. Households selected had members who were suffering from either diarrhea of unknown etiology or alleged typhoid fever. Hazard analyses and sanitary surveys included gathering data on time-temperature exposures of foods, collecting samples of food and drinking water, sampling sewage or drains, and obtaining stool specimens from persons with diarrhea and from family controls. Food samples were tested for aerobic mesophilic colony counts and common foodborne pathogens; specimens were tested for Salmonella, Shigella, Campylobacter and Yersinia. Campylobacter was isolated from two persons purported to have diarrhea, but neither Salmonella, Shigella nor Yersinia were recovered from alleged cases or controls. Salmonella agona was recovered from a latrine. Most foods were cooked to internal temperatures to or near to boiling. Those not promptly eaten were held at ambient room or outside temperatures until a subsequent meal, until a family member returned home, or until lunch time when taken to the fields. During these intervals, microorganisms multiplied and mesophilic aerobic organisms increased often reaching 10(8)/g or greater before consumption. None of these foods were reheated before eating. Bacillus cereus was isolated from 4 of 10 samples; one sample of 'moro' (beans and rice) exceeded 10(6)/g, two other samples exceeded 10(3)/g. Staphylococcus aureus was isolated from 7 of 14 samples, one exceeded 10(5)/g. Fecal coliforms were isolated from 8 of 14 food samples, five exceeded 10(5)/g. Neither Salmonella nor Shigella were isolated from any food, the community water supplies or from vessels of water within houses. Fecal coliform counts of water were less than 3/ml, except one sample from a clay vessel (9/ml). Risks associated with cooked foods which were not promptly eaten appeared to be greater than that associated with water.