^{Scombroid food poisoning}

What is scombroid food poisoning?

Ø  Scombroid food poisoning is a food borne illness that results from eating spoiled fish.

Ø  It is the second most common type of seafood poisoning.

Ø It is most commonly reported with mackerel, tuna, bluefish, mahi-mahi, bonito, sardines, anchovies, and related species of fish that were inadequately refrigerated or preserved after being caught.

    

Causes:

Unlike many types of food poisoning, this form of food poisoning is not brought about by ingestion of a bacterium or virus.

•   A naturally occurring amino acid called Histidine is responsible   for scombroid food poisoning.
•   Histidine exists naturally in many types of fish, and at temperatures above 16°C (60°F) on air contact it is converted to the histamine via the enzyme histidine decarboxylase. (this is one reason why fish should be stored at low temperatures)
•   Histamine is not destroyed by normal cooking temperatures, so even properly cooked fish can be affected. 
•   Histamine is a mediator of allergic reactions, so the symptoms produced are similar to severe allergic responses.

What are the sources of scombroid poisoning?

• The most common source of scombroid poisoning is fish of the Scombridae and Scomberesocidae families. They are known as "scombroid fish" and include tuna, bonito and mackerel.
•  These fish have large amounts of free histidine that may be converted to histamine during storage.
•   Scombroid poisoning can also be caused by

v  marlin and fish of other families, such as Clupeidae (herring, sardines),

v  Coryphaenidae family  (Mahi-mahi)

What are the Symptoms of scombroid food poisoning?

• Symptoms consist of skin flushing, throbbing headache, oral burning, abdominal cramps, nausea, diarrhea, palpitations, a sense of unease, and rarely collapse or loss of vision.
•   People with asthma are more vulnerable to respiratory problems such as wheezing.
•   Symptoms of poisoning can show within just minutes, and up to two hours, following consumption of a spoiled dish.

In the worst cases, the poisoning may cause:

•   Blurred vision
•   Respiratory stress
•   Swelling of the tongue

How long does it last?

Ø   Most people have mild symptoms that resolve within a few hours.

Ø   In some cases, symptoms may last for several days.

Who does it affect?

Ø  All consumers are at risk particularly those who eat the types of scombroid fish mentioned.

What can I do to protect myself and my family against scombroid poisoning?

•   Histamine formation in fish depends on the temperature at which the fish is kept from the time it is caught until it is consumed. So to avoid scombroid poisoning, it is very important to keep fish refrigerated when it is being transported and stored.
•   Fish with a bad odor or “honey-combed” appearance should not be consumed.
•   Buy seafood from reputable sources to ensure that products are properly chilled
•   If you think you have symptoms of scombroid poisoning, consult your doctor.

Remember!!

  Cooking or other heat treatments (such as canning or smoking) do not destroy histamine.

Treatment:

Ø  Treatment is generally not needed

For severe cases

•   Treatment is in the form of supportive care such as fluids and oxygen
•   Oral anti-histamines are very effective, showing improvement within -15 minutes.