AUTHORITIES ARE TRYING TO ESTABLISH THE SOURCE OF IMPORTED TUNA SOLD AT A SYDNEY CAFE THAT'S POISONED FOUR PEOPLE.
SCOMBROID POISONING
* also known as histamine poisoning, Scombroid is a type of food poisoning caused by high levels of histamine in fish which can occur if it isn't chilled properly
* freezing or cooking contaminated fish won't kill the toxin
* usually occurs in tuna, sardines, mackerel and swordfish
* treated with antihistamines
* extremely rare - of 57 people affected in Australia between January 2009 and December 2013, only nine were hospitalised and no deaths were reported
* Scombroid was linked to the death last year of Queensland mother and daughter Noelene and Yvana Bischoff who ate contaminated fish at a restaurant in Bali.
SYMPTOMS
* tingling or burning in the mouth, rash on the upper body, drop in blood pressure, headaches and itching
* may progress to nausea, vomiting and diarrhoea requiring hospitalisation, particularly for elderly patients
* usually occur within 30 minutes after eating poisoned fish and can last from three hours to several days.
(Sources: Federal Department of Health, Food Standards Australia New Zealand and NSW Food Authority, Food Safety Information Council).
