Staphylococcus food poisoning in the early century

STAPHYLOCOCCUS FOOD POISONING

This form of acute food poisoning is caused by the presence in food of certain strains of staphylococcus albus or aureus. These organisms multiply in food and produce an enterotoxin which is not destroyed by boiling.


Due to the fact that the toxin is preformed in the food before consumption, the incubation period is very short. The onset is abrupt and often violent, with nausea and vomiting, but there is rarely any elevation of temperature. Prostration and severe diarrhoea occur in some cases.

Geographical Distribution

This disease occurs throughout the world, but is especially prevalent in areas where the atmospheric temperature is such as to promote rapid bacterial growth in food.

The Parasite

Strains of white or yellow staphylococci, which produce this clinical condition, differ from others of the same species b the fact that they produce an enterotoxin which is not destroyed by boiling or refrigeration. The presence of this toxin can be demonstrated only by administering filtrates of cultures to laboratory animals or human volunteers.


Epidemiology

The source of infection is man, who may carry the causative organism in chronic infections of the nose or throat or in pyogenic skin lesions. Foodstuffs are contaminated either by bucal spray or by direct contact with the infected cutaneous lesions.

In order that there may be multiplication of the organisms and sufficient production of toxin to cause food poisoning, it is necessary that the initial contamination should be moderately heavy; that the foodstuff should be a good medium for the growth of staphylococci, and should stand for several hours at a suitable temperature.

The foods which are most commonly the cause of staphylococcal food poisoning are sauces, custards, cream fillings for cakes, meat and meat products. All persons are susceptible and infection does not appear to confer any immunity.

Diagnosis

The incubation period may be anything from one to eleven hours. This short incubation period is a characteristic of the condition and helps to differentiate it from food poisoning due to salmonella organisms. It cannot be differentiated in an individual from one acute gastro-enteritis due to other causes by any laboratory test at present available.

When it occurs as a sudden outbreak in a group of persons who have shared the same meal a few hours previously the diagnosis may be made on epidemiological grounds. In such cases enquiry should at once be made regarding the foods consumed at the meal in question, and whether or not he was subsequently ill. As a result of this enquiries it may be possible to ascertain which food was responsible. In some cases an unconsumed portion of the suspected food may still be available and, if so, a sample should be sent to a laboratory for examination.


Control

Due to the fact that the toxin is preformed in the food before consumption, the incubation period is very short. The onset is abrupt and often violent, with nausea and vomiting, but there is rarely any elevation of temperature. Prostration and severe diarrhoea occur in some cases.

Prepared foods should be handled as little as possible and kept chilled until served. Such foods as hams may be free of infection when prepared but may become infected if kept at room temperature and cut from day to day; they should be stored in a refrigerator. It is to be noted that the growth of staphylococci causes no abnormal odour or taste in food.