Hazards and Critical Control Points of Food Preparation in Homes in Which Persons Had Diarrhea in Zambia

Following identification of some cases of diarrhea from persons who either sought treatment at a health clinic that served two townships near a large city in Zambia or got water from a deep protected well in one of the townships, hazard analyses were done of food preparation and storage practices at 17 homes. Samples of foods at various stages of preparation, foods held overnight, and drinking water were collected from the homes of the ill persons and were tested for common foodborne pathogens and indicator organisms. Salmonella was isolated from a sample of leftover kapenta (cooked dried minnows). Thermotolerant coliforms and Escherichia coli were isolated from water from shallow wells and a treated community supply. Although thermtolerant coliforms were not recovered from the protected well site, they were isolated from a sample of water collected in a home that used this supply. Several leftover foods, however, contained much larger populations of thermotolerant coliforms and larger populations of aerobic mesophilic organisms than the water. Furthermore, leftover nshima (boiled and whipped corn meal) and porridge contained large populations (>10⁵) of Bacillus cereus per gram. Foods during cooking attained temperatures that would have been lethal to vegetative cells of foodborne pathogens. After cooking, they were subjected to time-temperature abuse during holding until eaten or while held overnight.