MI4.5-6 | Food Poisoning & Acid-Peptic Disease (H. pylori) — Summary & Reflection

REFLECT

A food inspector must investigate a school outbreak involving 80 students who developed vomiting within 3 hours of lunch. The kitchen confirms that cold rice from the previous night was reheated and served with chicken curry cooked fresh. Outline your approach: which pathogen(s) do you suspect? What food samples would you send? What tests would you request? How do you distinguish a 'toxin in food' scenario from an 'organism in food' scenario—and does the distinction change public health notification requirements?

KEY TAKEAWAYS

Key takeaways from this SDL:

1. Three types of food poisoning: Intoxication (preformed toxin, short incubation, no fever), toxico-infection (toxin produced in gut, 8–16 h), infection (mucosal invasion, >24 h, fever).
2. Staphylococcal food poisoning: Heat-stable SE A in cream foods; 1–6 h onset; vomiting dominant; culture food not patient.
3. Bacillus cereus: Two syndromes—emetic (cereulide, fried rice, 1–5 h) and diarrhoeal (enterotoxin, 8–16 h).
4. Botulism: Preformed botulinum toxin in canned/fermented food → flaccid descending paralysis; no diarrhoea; mouse inoculation test.
5. H. pylori: Microaerophilic spiral rod; urease = key virulence + diagnostic tool; CagA + VacA → chronic gastritis → peptic ulcer → gastric cancer.
6. H. pylori diagnosis: Invasive — rapid urease test (CLO), histology, culture. Non-invasive — UBT (eradication check), stool antigen (accurate). Serology not for post-treatment.
7. Eradication therapy: PPI + clarithromycin + amoxicillin × 14 days; confirm eradication with UBT at 4 weeks post-therapy.