Food Poisoning


Food Poisoning includes all illness resulting from ingestioon of food containing bacterial or non-bacterial products. But this term is usually restricted to acute gastroenteritis due to bacterial infection (eg. Salmonella etc.) of food or drink.


  1. Poisoning due to bacteria and toxins
  2. Poisoning due to vegetable origin
    1. Mushrooms (poisonous)
    2. Lathyrus sativa (Khesari dal etc.)
  3. Poisoning due to animal origin - Poisonous fish and mussel.
  4. Chemical : Accidentally or intentionally added poisonous chemical products eg. radio nucleotides etc.

Food Poisoning Characterized by -

  1. Simultaneous illness of many persons of all the same time.
  2. History of common food intake by all patients.
  3. Common signs and symptoms in all patients.

Bacterial Food Poisoning

Bacterial food poisoning is of three types :

  1. Infection type
  2. Toxin type
  3. Botulism

I) Infection type :

Infection type of food poisoning results from ingestion of microorganisms that multiply in gastrointestinal tract eg. Salmonella and Shigella group of organisms.

Signs and symptoms

  1. Nausea
  2. Vomiting
  3. Abdominal pain
  4. Foul smelling watery diarrhea stained with blood or mucus.
  5. Muscular weakness
  6. Fever


  1. Gastric lavage
  2. Purgatives like liquid paraffin (15-30ml/day), Lactulose (10-20gm/day) etc.
  3. Glucose saline infusion to eliminate toxins from the system.
  4. Antibiotics are given depending upon causative organism eg. Salmonella group- Chloramphenicol 1-3gm daily in four divided doses.
  5. Shigella group - Ampicillin 0.5-2gm oral/I.V/I.M. depending upon the severity of infection every 6 hours.
  6. The rest of the treatment is symptomatic.

Post-mortem appearances

  1. The mucosa of the alimentary canal is inflamed, congested and ulcerated.
  2. Fatty degeneration of liver.
  3. Internal organs may be congested.
  4. The causative organism can be isolated from the blood or viscera.

II) Toxin type

Toxin type of food poisoning occurs by a strain of organisms that produce enterotoxin eg. Staphylococci, Proteus vulgaris, Streptococcus viridians, B.coli, Clostridium welchii etc. Food such as milk, custard, egg and previously prepared meat dishes are the chief sources.

Signs and symptoms

  1. Salivation
  2. Acute gastroenteritis.


Same as in infective type of food poisoning

Post-mortem appearances

Same as in infective type of food poisoning

III) Botulism

Botulism type of food poisoning is caused by the ingestion of exotoxins of the clostridium botulinum contained in the undercooked foods, potted meats, tinned fish, canned acidic vegetables and fruits etc.

Action : The toxin inhibits acetylcholine and paralyses the muscles by blocking the nerve impulses at the myoneural junction.

Signs and Symptoms

  1. Dry throat
  2. Difficulty in swallowing and speech
  3. Diplopia (perception of two images of a single object) due to ocular muscle palsy.
  4. Constipation
  5. Hypothermia
  6. Respiratory insufficiency
  7. Urinary retention
  8. The patient is conscious till death.

The Gastro intestinal symptoms like nausea, vomiting and abdominal pain are rare in botulism type of poisoning.

Diagnosis : diagnosis of botulism can be made by the isolation of the bacillus from food, patient's vomit, feces or viscera.

Fatal dose : 5 gm or even less.

Fatal period : 24-48 hours


  1. Gastric lavage
  2. Polyvalent botulinum antitoxin (types A,B and E) one vial by slow I.V in normal saline and one vial I.M. It should be repeated at 2-4 hours intervals I.V.
  3. 50 ml Botulism immune globulin (BIG) I.V. daily, till the patient recovers.
  4. Purgatives like liquid paraffin (15-30ml/day), Lactulose (10-20 gm/day) etc.
  5. Maintain fluid and electrolyte balance
  6. Artificial respiration, if needed.
  7. The rest of the treatment is symptomatic.

Post-mortem appearance

  1. Congestion and hemorrhage in kidneys, liver and meninges.
  2. Degenerative changes in the liver and Kidneys.
  3. Histological examination of the organs may show thrombosis
  4. The causative organism can be isolated from viscera.

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