Suspected Marine Neurotoxin Poisoning Probed in Kerala

Tetrodotoxin Under Investigation After Vizhinjam Incident

Food safety authorities in Thiruvananthapuram have initiated an investigation into a suspected case of marine neurotoxin poisoning following multiple instances of severe illness linked to seafood consumption at a restaurant in Vizhinjam. The episode began on the night of 16 February, when three members of a six-member family developed acute symptoms. Two individuals succumbed within hours. In the following days, six additional cases of critical illness were reported, all associated with the same establishment and date.

Shift from Conventional Food Poisoning

Preliminary findings have excluded typical food poisoning caused by bacterial contamination or spoilage. The rapid onset of symptoms and clustering of cases directed attention toward naturally occurring marine biotoxins. Investigators are currently examining the likelihood of tetrodotoxin (TTX) exposure.

Fish Roe Identified as Likely Source

Authorities have identified fish roe as the probable vehicle of contamination, as all affected individuals had consumed the item. Fish roe can bioaccumulate toxins depending on the originating species and environmental conditions. The pattern of illness supports the hypothesis of a potent toxin rather than microbial agents.

Earlier assessments considered ciguatoxin, particularly following its recent detection in red snapper samples from the Tamil Nadu coast. However, the clinical presentation observed in patients does not align with characteristic ciguatera symptoms.

Neurological Symptoms Raise Alarm

Medical evaluations revealed dominant neurological manifestations, including rapid paralysis and severe systemic distress. The short interval between ingestion and deterioration, combined with fatalities occurring within hours, is consistent with documented tetrodotoxin poisoning cases.

Tetrodotoxin is among the most lethal marine neurotoxins. It disrupts nerve signal transmission by blocking sodium channels, leading to muscular paralysis and respiratory failure. Crucially, TTX remains stable under heat and cannot be neutralised through cooking.

Forensic Confirmation Pending

Toxicological analysis of biological samples from the deceased is underway. Definitive identification of tetrodotoxin requires laboratory confirmation. Parallel investigations are tracing the seafood supply chain to determine the contamination pathway.

Important Facts for Exams

• Tetrodotoxin (TTX) is a heat-stable marine neurotoxin with no specific antidote.

• TTX blocks sodium channels, causing paralysis and respiratory complications.

• Ciguatoxin originates from marine dinoflagellates and accumulates in reef fish.

• Marine biotoxins can enter the human food chain through bioaccumulation.