HAZARDS AND CRITICAL CONTROL POINTS OF FOOD VENDING OPERATIONS IN A CITY IN ZAMBIA

Hazard analyses were conducted at several cooked food vending operatio ns in a large city in Zambia, near a downtown bus park and at a large market. Samples of raw, processed, and cooked foods sold on streets or by small food shops were collected and tested for common foodborne pa thogens and indicator organisms. Results showed that some raw foods (g round meat, chicken, chicken intestine) or processed foods (dried minn ows; kapenta) were contaminated by salmonellae or contained high popul ations of Staphylococcus aureus (pasteurized milk) or Bacillus cereus (caterpillars). Cooking usually gave time-temperature exposures that w ould have been lethal for vegetative forms of foodborne pathogens. Hol ding of foods other than nshima often provided time-temperature exposu res conducive to microbial growth, particularly in foods held overnigh t. Large populations of aerobic mesophilic organisms, thermotolerant c oliform bacteria, and sometimes Escherichia coli were recovered from t hese foods. Ten million Clostridium perfringens per gram were isolated from a sample of leftover beef stew. Large populations (> 10(5)) of S . aureus were recovered from a sample of leftover chicken, and large p opulations of B. cereus (> 10(7)) were isolated from leftover rice. Ti me-temperature exposures during reheating had variable effects in term s of killing the microorganisms that germinated from surviving spores or that reached the foods after cooking, but heat-stable toxins would not have been inactivated.