Did marine algal toxins cause Vizhinjam seafood deaths ?

In the absence of any primary evidence that food poisoning — due to spoilage of food or bacterial contamination — could have caused the death of two persons on Tuesday, who suddenly took ill after consuming seafood, Food Safety authorities are exploring the possibilities whether naturally occurring marine algal toxins could have led to the contamination of sea food which was procured by the restaurant at Vizhinjam

They said that three more persons who had consumed fish from the same restaurant had also fallen ill but that they were currently stable in a private hospital in the city

However, the fact that at least 600 to 700 persons had visited the restaurant on that particular day and that not all of the family members had taken ill has been confusing, officials said.

Three of a family of six persons who had consumed seafood delicacies at Vizhinjam had taken ill soon after they finished dinner Monday night. Two persons had died, while one person is currently stable at Thiruvananthapuram Medical College.

The postmortem reports of the deceased had not given any evidence of food poisoning and detailed chemical analysis was awaited to ascertain the actual cause of death. The results of the water samples and fish samples taken from the cold storage of the restaurant (these were not the same fish consumed by the deceased) are also awaited.

Food Safety authorities said that they decided to explore the algal toxins angle following discussions with the doctors who treated the deceased and also because the department had in recent times encountered a few cases of fish contaminated by marine algal toxins like Ciguatoxin.

Ciguatoxin is a toxin made by marine algae (dinoflagellates) that is common in tropical and subtropical fishing waters during harmful algal blooms and this can contaminate shellfish as well as some varieties of fish like Red snapper. This is a heat-stable toxin, which means that it cannot be eliminated through normal cooking or any other form of food processing

“We had identified ciguatoxin recently in a sample of Red snapper at CIFT and as this had been procured from the Tamil Nadu coast, we had written to the food safety authorities there,’ officials said.

Food Safety officials have now taken samples of mussels, prawns and squid from the centre from where the restaurant usually procures fish and have sent these samples to CIFT for toxicology studies.

Roe or fish eggs, which the family had consumed, was procured by the restaurant from a trader at Muttam in Tamil Nadu on February 15. Hence the food safety authorities in Tamil Nadu have been informed and sample studies have been requested.

The toxicology studies at CIFT could take a while, though the results on the other samples are expected in a day or two.

Food Safety authorities said that they were conferring with the Fisheries authorities if there were fishing spots that needed to be avoided by fishermen and if alerts should be issued.