Six tourists were hospitalized at Bach Mai Hospital in Ha Noi after consuming eel contaminated with ciguatoxin, a potent marine toxin. The patients, who dined at a local restaurant on the evening of 7/3, began experiencing severe symptoms one to three hours later, even those who ate only two small pieces of fish. By 13/3, Doctor Nguyen Trung Nguyen, Director of the Poison Control Center at Bach Mai Hospital, confirmed the group's health had fully stabilized.

Doctor Nguyen examining the reflexes of the eel poisoning patients. *Photo: Nguyen Ha*

The poisoning symptoms started with a burning sensation in the throat and numbness of the lips and tongue. This quickly escalated to muscle and joint pain, dizziness, a drop in blood pressure, vomiting, and diarrhea. A distinct symptom reported by the patients was a painful, irritating sensation when touching cold water, indicating sensory disturbances. Initial first aid was administered at a lower-level medical facility before the six most severely affected individuals were transferred to Bach Mai Hospital on 8/3. Through examination and epidemiological investigation, specialists identified ciguatoxin, present in the eel meat, as the primary cause.

Doctor Nguyen noted that ciguatera poisoning is the most common type of marine fish poisoning, even surpassing pufferfish poisoning, yet public awareness remains low. Microalgae produce this toxin in seawater. Through the natural food chain, the toxin gradually accumulates in the bodies of large coral reef fish such as eel, barracuda, grouper, and snapper. Alarmingly, ciguatoxin is invisible, tasteless, and resistant to high-temperature cooking, deep freezing, or salting. It is impossible for humans to distinguish between contaminated and clean fish with the naked eye.

Modern medicine has not yet discovered a specific antidote for ciguatoxin. Consequently, doctors primarily focus on symptomatic treatment, maintaining heart rate, blood pressure, and respiratory function. To prevent poisoning, health experts advise people to limit their consumption of large natural coral reef fish and to always discard internal organs, as these concentrate the highest levels of toxins. Choosing industrially farmed fish offers greater safety due to strict control over feed sources. Should symptoms such as muscle weakness or arrhythmia occur after consuming seafood, individuals should immediately call for emergency services and quickly go to the nearest medical facility.

Le Nga