New South Wales Health has reported four cases of scombroid food poisoning linked to imported canned tuna served at Sydney Cafe prompting an investigation.
The product in question, John Bull Tuna Chunky Style in Sunflower Oil is imported into Australia from Thailand. This is minor brand catering product that is not generally available to the public.
NSW Food Authority reports that this incident is isolated to one group at the one location. The café has subsequently ceased serving tinned tuna.
Scombroid fish poisoning is an acute syndrome characterized by facial flushing, sweating, rash, a burning or peppery taste in the mouth, diarrhea, and abdominal cramps and usually resolve within several hours without medical intervention.
This is due to histamine toxicity from the ingestion of spoiled fish. The fish do not contain high levels of histamine when caught; instead they have histidine in their flesh. Histamine is produced during spoilage from common surface bacteria on the fish. The histamine is not destroyed by cooking.
The type of fish implicated in this food poisoning are mainly of the scombroid type; tuna, mackerel, skipjack and albacore. Some non-scombroid fish such as mahimahi, bluefish, anchovies, and herring have been implicated.
Risks are greatest for fish imported from tropical and semi-tropical areas and fish caught by recreational fisherman who may not have the refrigerated storage for larger fish.
In addition to the symptoms above, which generally appear quite rapidly (within minutes to hours), more severe symptoms may include difficulty in swallowing, respiratory distress and blurred vision. People on isoniazid may have more severe symptoms. Anti histamines are given in severe cases. Deaths are rare.
Adequate and rapid refrigeration of the fish will prevent spoilage.
The diagnosis is made on symptoms and tends to be fairly evident. Several people may come down with this at the same time.
There is no laboratory testing on the patient that is considered helpful. Measuring histamine levels on the suspected fish can be used for confirmation.