Staphylococcal Food Poisoning
Staphylococcal Food Poisoning
It is about as common as Salmonella food poisoning. The reasons indicated for its occurrence are as follows:
Agent
Enter toxins of certain strains of coagulase–positive Staphylococcus Aureus. At least, 5 different enter toxins have been identified, and a sixth may exist. Toxins can be formed at optimum temperatures of 35 deg. to 37deg. C. These toxins are relatively heat–stable and resist boiling for 30 minutes or more.
Source
Staphylococci are ubiquitous in nature, and are found on the skin and in the nose and throat of men and animals. They are a common agent of boils and pyogenic infections of man and animals. Cows suffering from mastitis have been responsible for outbreaks of food poisoning involving milk and milk products. The foods involved are salads, custards, milk and milk products which get contaminated by staphylococci.
Incubation Period
It’s about 1–6 hours. The incubation period is short because the “Preformed” toxins act directly on the intestine and CNS. The illness becomes manifest by the sudden onset of vomiting. Unlike Salmonella food poisoning, Staphylococcal food poisoning rarely causes fever. Death is uncommon.
Botulism
It is most serious but rare. It kills two–thirds of its victims!
Agent
Exotoxin of Clostridium Botulinum generally Type A, B, or E.
Source
The organism is widely distributed in soil, dust and the intestinal tract of animals and enters food as spores. The foods most frequently responsible for botulism are home preserved foods such as home–canned vegetables, smoked or pickled fish, home–made cheese and similar low acid foods. In fact, botulism derives its name from the Latin word for sausage (botulus).
Incubation Period
About 12–36 hours.
Mechanism of Food Poisoning
The toxin is preformed in food (intradietetic) under suitable anaerobic conditions. It acts on the parasympathetic nervous system. Botulism differs from other forms of food poisoning in that the gastrointestinal symptoms are very slight. The prominent symptoms are dysphagia, diplopia, ptosis, dysarthria, blurring of vision, muscle weakness and even quadriplegia. Fever is generally absent, and consciousness is retained. The condition is frequently fatal, death occurring 4–8 days later due to respiratory or cardiac failure. Since the toxin is thermo labile, the heating of food which may be subjected to 100 deg. C for a few minutes before use will make it quite safe for consumption.
Botulism occurring in infants is called “Infantbotulism”. It is due to infection of the gut by CI Botulinum with subsequent in vivo production of toxin.
Anti–toxin is of considerable value in the prophylaxis of botulism, when a case of botulism has occurred, anti–toxin should be given to all individuals partaking of the food. The dose varies from 50,000 to 1,00,000 units. The anti–toxin will be of no avail if the toxin is already fixed to the nervous tissue. Guanidine Hydrochloride reverses the neuromuscular block of botulism. When combined with good medical and nursing care, the drug can be a useful adjunct in the treatment of botulism. Active immunization with botulinum toxoid to prevent botulism is also available.
