Food Poisoning

– Enteric or neural intoxication following ingestion of bacterially contaminated food.

Causes and Incidence

Food poisoning is caused by one of the following organisms: staphylococcal enterotoxins, Clostridium botulinum, Clostridium perfringens, Vibrio parahaemolyticus, or Bacillus cereus. The resulting illness is noncommunicable.

Disease Process

The causative organism multiplies in the food before ingestion; the pathogenesis is organism specific. Staphylococcal enterotoxins form in foods held at room temperature. They act on the gastric mucosa, producing hyperemia, erosion, petechiae, and purulent exudate. C. perfringens reproduces rapidly in cooled and reheated food and acts on the epithelial layer of the ileum, increasing absorption of fluid, sodium, and chloride and inhibiting glucose absorption. V. parahaemolyticus multiplies in uncooked seafood and invades the intestinal tissue, producing necrosis, ulceration, and granulocytic infiltration of the mucosa. B. cereus, an aerobic spore, multiplies in foods held at room temperature and attacks either the gastric or intestinal mucosa. C. botulinum forms a toxin in improperly processed foods in anaerobic conditions; it is a neurotoxin that impairs autonomic and voluntary neurotransmission and causes muscular paralysis.

Symptoms

The signs and symptoms depend on the causative agent.

Staphylococci
Symptoms appear within 7 hours of ingestion: weakness, acute nausea and vomiting, intestinal cramps, diarrhea

Enteric type (C. perfringens, V. parahaemolyticus, B. cereus)
Symptoms appear within 24 hours of ingestion: nausea, vomiting, abdominal pain, diarrhea

C. botulinum
Symptoms appear within 36 hours of ingestion: dry mouth, diplopia, loss of pupillary light reflex; nausea, vomiting, cramps, and diarrhea precede dysphagia, dysarthria, and progressive descending muscular paralysis

Potential Complications

The complication of enteric manifestations is dehydration, and infants and small children are most susceptible. Botulism is fatal in about 10% of cases, usually because of respiratory failure.

Diagnostic Tests

Cultures
Stomach contents, feces, or suspected food for causative organism.

Serum
Positive for botulinal toxins.

Treatments

Surgery
Tracheostomy if necessary for airway with botulism.

Drugs
Trivalent botulinal antitoxin as soon as possible after onset of botulism.

General
Botulism: gastric lavage, mechanical ventilation if necessary, nasogastric tube feedings, fluid and electrolyte replacement, prevention of skin breakdown and contractures during paralysis, minimization of stimuli, precise communication because of altered vision and loss of speech, allaying anxiety about paralysis and treatment.
Other causes: fluid and electrolyte replacement, instruction in prevention.