With no primary evidence that food poisoning — due to food spoilage or bacterial contamination — may have caused the deaths of two people who suddenly fell ill after eating seafood on Tuesday, food safety authorities are investigating the possibility that naturally occurring toxins from seaweed may have led to the contamination of seafood procured by a restaurant in Vizhinjam.
They said three other people who consumed fish from the same restaurant also fell ill, but that they are currently stable at a private hospital in the city.
However, the fact that at least 600 to 700 people visited the restaurant that day and that not all family members became ill is confusing, officials said.
Three of a family of six who were consuming seafood in Vizhinjam fell ill shortly after finishing their dinner on Monday evening. Two persons have died while one person is currently stable at Thiruvananthapuram Medical College.
Post-mortem reports on the deceased gave no evidence of food poisoning and a detailed chemical analysis was awaited to determine the actual cause of death. The results of water samples and fish samples taken from the restaurant’s cold storage (they were not the same fish consumed by the deceased) are also awaited.
Food safety officials said they decided to look into the algal toxins angle after discussions with doctors who treated the deceased and also because the department had recently encountered several cases of fish contaminated with seaweed toxins such as ciguatoxin.
Ciguatoxin is a toxin produced by marine algae (dinoflagellates) that is common in tropical and subtropical fishing waters during harmful algal blooms and can contaminate shellfish and some fish species such as red snapper. It is a heat-stable toxin, meaning it cannot be removed by normal cooking or other forms of food processing.
“We have recently identified ciguatoxin in a red snapper sample at CIFT and since it was sourced from the Tamil Nadu coast, we have written to the food safety authorities there,” officials said.
Food safety officials have now taken samples of mussels, prawns and squid from the center, where the restaurant usually buys its fish, and sent those samples to CIFT for toxicology studies.
The roe or fish eggs that the family consumed were bought by the restaurant from a trader in Muttam, Tamil Nadu on February 15. Hence, Tamil Nadu Food Safety Authorities were informed and sample studies were requested.
Toxicology studies at CIFT can take a while, although results for other samples are expected in a day or two.
Food safety authorities said they are consulting with fisheries authorities to see if there are fishing spots that anglers should avoid and whether warnings should be issued.
Published – 18 Feb 2026 22:03 IST