Foodborne Illness and Pathogens
Foodborne illness is any illness caused by eating contaminated food. This domain tests whether you can name the main pathogens found in Jamaican food operations, link each to its usual food vehicle, and explain how time and temperature let organisms multiply or form toxin.
Three routes to illness
- Infection – live organisms colonise the gut: Salmonella, Campylobacter, E. coli O157:H7, Listeria, norovirus, hepatitis A, Vibrio cholerae.
- Intoxication – toxin already formed in the food before eating: Staphylococcus aureus, Bacillus cereus (emetic type), Clostridium botulinum.
- Toxin-mediated infection – organisms grow in the gut and release toxin there: Clostridium perfringens, E. coli O157:H7.
Food vehicles to know
Poultry and eggs (Salmonella, Campylobacter); minced beef and unpasteurised milk (E. coli O157:H7); soft cheese, pâté and chilled ready-to-eat meats (Listeria – it grows in the fridge); cooked rice, pasta and flour-based sauces (Bacillus cereus); stews, gravies and large roasts cooled slowly (Clostridium perfringens); shellfish (Vibrio); salads and iced drinks handled with bare hands (norovirus, hepatitis A); water and street foods (typhoid).
FATTOM
Bacteria need Food, Acidity near neutral (pH 4.6–7.5), Time, Temperature inside the danger zone, Oxygen (most do, but Clostridium and Listeria do not need it) and Moisture (water activity above 0.85).
Worked example. Rice and peas cooked at 11 a.m. sits on the stove until 4 p.m., then is reheated. Risk: rice is the classic Bacillus cereus vehicle and its spores survive cooking. During five hours in the danger zone the spores germinate and heat-stable emetic toxin forms. Reheating kills the cells but not the toxin, so vomiting follows in 1–6 hours. Correct practice: hold above 60 °C, or cool 60 °C to 21 °C within 2 hours and to 5 °C within 4 more, then reheat to 74 °C.
Traps. Cooking does not "kill everything" – spores and pre-formed toxins survive. Listeria is not a warm-weather-only organism; it multiplies under refrigeration. Mixing up intoxication and toxin-mediated infection costs marks.