The Centre for Health Protection (CHP) of the Department of Health (DH) and the Food and Environmental Hygiene Department (FEHD) are jointly investigating a case of scombroid fish poisoning affecting a total of five persons.
Investigation by CHP showed that the affected persons, which comprised three men and two women aged from 24 to 38, developed symptoms of scombroid fish poisoning including flushing, palpitation, dizziness, vomiting and diarrhea half to 1.5 hours after consuming lunch supplied and delivered by a caterer in Central on January 16.
Their symptoms were generally mild. Four of them sought medical treatment. One was admitted to a private hospital and was discharged on January 17.
Upon receipt of the report, FEHD inspected the concerned food premises and collected food samples for analysis.
Results of laboratory test showed that a sample of chilled butterfish fillet contained histamine at a level of 1700 ppm. According to the Codex Alimentarius, histamine levels above 200 ppm in certain fish species require follow up actions.
The FEHD is taking follow up actions including tracing the source of the fish in question.
A spokesman for the FEHD said, "Histamine is commonly found in certain kinds of fish such as tuna and mackerel, as a result of bacterial spoilage.
"Formation of histamine in fish is usually related to improper control of temperature during storage. Poisoning incidents have been reported to be related to canned fish that was not properly stored after opening."
"The most common symptoms of poisoning are those resembling allergic reaction including tingling and burning sensations around the mouth, facial flushing, sweating, nausea, vomiting, headache, dizziness and rash," the spokesman said.
"The trade and the public are advised to purchase fish such as tuna and mackerel products from reliable sources. Fish should be stored at 4 oC or below and canned fish, once opened, should be consumed as soon as possible. They should discard fish found to have an unusual odor," he added.
Ends/Friday, January 25, 2008