Scrombotoxins
SCOMBROTOXIC FOOD POISONING
What is Scombrotoxic food poisoning?
Scombrotoxic food poisoning is usually caused by the bacterial spoilage of oily fish, such as tuna and mackerel. This produces histamine and related chemicals. Other foods such as Swiss cheese have very occasionally been affected.
How do I know that I have Scombrotoxic food poisoning?
Diagnosis is usually based on a person showing the characteristic symptoms but it can only be confirmed by the detection of high levels of histamine in the suspect food.
Who can get Scombrotoxic food poisoning?
Anyone eating affected food can get Scombrotoxic food poisoning. However, the symptoms may be more severe in the elderly and in susceptible individuals.
How is it spread?
Scombrotoxin forms in a food when certain types of bacteria are present and are allowed to grow by not being kept under effective refrigeration. Once it has been produced the toxin is very heat resistant. Neither cooking, canning nor freezing will reduce the toxic effect. Incidents tend mainly to be associated with fresh tuna but the toxin may also be formed in canned fish that has been contaminated after opening. Distribution of the toxin within an individual fish may be uneven with only some individual fillets or cans causing illness. Even though the toxin is produced as a result of spoilage bacteria the food may not necessarily look, smell, or taste any different.
What are the symptoms?
Initial symptoms may include a tingling or burning sensation in the mouth, blushing or a rash on the face or the upper body, and a drop in blood pressure. Frequently, headaches, sweating and itching of the skin are encountered. The symptoms may progress to nausea, abdominal pain, vomiting and diarrhoea. Severe cases may require admission to hospital, particularly in the case of elderly or vulnerable patients.
How can I prevent the spread of infection?
Handwashing
This is the most important factor in preventing the spread of infection.
Thoroughly wash your hands with soap in warm running water:
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AFTER using or cleaning the toilet
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AFTER touching anything contaminated by diarrhoea or vomiting
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AFTER attending to anybody who is unwell
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AFTER handling dirty laundry, clothing or bedding
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AFTER handling used nappies
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BEFORE handling, preparing, serving, or consuming food or drink
People who are ill should ideally use bactericidal liquid soap and separate towels or disposable paper tissues. A nailbrush can assist you to clean under your fingernails. Always dry your hands well as this helps to remove bacteria.
How soon after exposure do symptoms occur?
Generally between 10 minutes and 2 hours after eating the affected food. The duration of the illness is usually short, but may last several days.
Do infected people need to stay away from work or school?
All cases of gastroenteritis are regarded as potentially infectious. People should normally stay away from work or school until free from diarrhoea and vomiting. Inform your employer, child carer, nursery or school as soon as possible to help them identify if they may have an outbreak.
Infected people in ‘high risk’ groups must stay away while they have symptoms. This includes:
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Food handlers involved with unwrapped or ready to eat food,
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Staff of health care facilities in contact with food or patients,
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Children aged below 5 years attending nurseries, playgroups, etc
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Older children and adults who may find it difficult to implement good standards of personal hygiene. Such people may return to work or school when they have recovered, provided that they wash their hands thoroughly after using the toilet.
How can I prevent it spreading?
Cleaning the toilet
For as long as people are unwell:
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Wipe the toilet seat with disinfectant after each use
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Wash and disinfect other items like bedpans or potties after each use.
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Use a cloth soaked in disinfectant to wipe the toilet seat, flush handle, washbasin taps, and door handle two or three times a day.
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Clean the toilet bowl using a (toilet) brush and disinfectant.
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Rinse the brush by flushing the toilet, and replace in its holder.
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Keep any rubber gloves used for cleaning the toilet for this use only. •Flush the toilet with the seat and lid down.
Laundry
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Keep dirty laundry from anyone with food poisoning separate if possible remove any heavy soiling into the toilet before washing
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wash soiled clothing and bedding separately on
• as hot a washing programme as possible without exceeding fabric care instructions.
Points to remember
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make sure everybody follows these precautions assist young children to wash
their hands properly
Further advice is available by contacting your Doctor or from Kennet District Council
Environmental Health & Protection Services