Some children took severely ill when a dead rat was allegedly found in dinner served at a government residential school in Hardauli village in Banda district on Sunday. The students started vomiting after which a team of government doctors was rushed to the school. The students are feeling better now reports TOI.

In this case it looks like the people vomited after they came to know about the rat and not because of the rat poisoning. If the rat is boiled and cooked in the food it cannot cause poisoning. If a dead rat is put in the boiled food again it is unlikely to cause poisoning. In any way if it was poisoning it was staph bacteria poisoning, which is self-limiting and causes no death.

One can classify food poisoning depending on the onset of symptoms as follows:

  • Rapid symptoms within 6-12 hours: are due to organisms that make a toxin in the food before the food is consumed. Symptom is predominantly vomiting. Examples are Staphylococcus aureus, Bacillus cereus emetic toxin and botulism.
  • Symptoms after 24 hours: are due to pathogens that make toxin once they have been ingested. They mainly cause diarrhea that may be watery (Vibrio cholerae or E. coli) or bloody (Shiga toxin-producing E. coli).
  • Symptoms after variable time: are due to microbes that cause pathology by either damaging the epithelial cell surface or by actually invading across the intestinal epithelial cell barrier. They can produce a wide spectrum of clinical presentations from watery diarrhea (Cryptosporidium parvum, enteric viruses) to inflammatory diarrhea (Salmonella, Campylobacter, Shigella) or systemic disease (L. monocytogenes).

Food poisoning can also be classified depending on the type of symptoms vomiting or diarrhea.  A sudden onset of nausea and vomiting is likely due to the ingestion of a preformed toxin, such as S. aureus enterotoxin or B. cereus emetic toxin, or a chemical irritant. There is no risk of person-to-person spread.

When the poisoning presents with diarrhea, the organisms are V. cholerae, Clostridium perfringens, enterotoxigenic E. coli, B. cereus, rotavirus, astroviruses, enteric adenoviruses and Noroviruses, and the parasitic organisms, Cryptosporidium parvum and Cyclospora cayetanensis.

There are clinical clues that should increase suspicion that a food-borne microbe is causing inflammatory diarrhea. Such symptoms and signs include: Passage of diarrhea with blood or mucus; presence of severe abdominal pain and occurrence of fever. The most likely pathogens in patients with inflammatory diarrhea are Salmonella or Campylobacter.