Five men have been poisoned in Japan after allegedly asking a restaurant to serve them banned parts of the world’s most toxic fish.
The men were having dinner on Friday night in the western city of Wakayama when they ate puffer fish liver, which prompted vomiting and breathing difficulties early the next morning.
Puffer fish – also called blowfish or fugu in Japanese – are the world’s most toxic group of fish and their livers, ovaries and skin contain tetrodotoxin, 100 times more lethal than cyanide.
Yet eating the fish’s flesh is a tradition in Japan, where wealthy diners play the Russian roulette of the restaurant world by dining on sashimi slivers so thin they are almost transparent.
According to a city health official, the men asked to eat a banned, toxic part of the fish – which the most foolhardy fugu aficionados are said to enjoy for the tingling it produces on the lips.
The tingling is only the first symptom of tetrodotoxin poisoning, and is seen as part of the thrill for lovers of the fish.
But if the toxin is served in any significant quantity it then paralyses the muscles, suffocating victims as it reaches their chests and diaphragms while they are still conscious.
The health official said the men were in their 40s and 50s and the restaurant was shut down for five days from yesterday amid an investigation.
The U.S. Centers for Disease Control reports that on June 13, 2014, two patients went to the Hennepin County Medical Center Emergency Department in Minneapolis, Minnesota, with symptoms suggestive of tetrodotoxin poisoning (i.e., oral paresthesias, weakness, and dyspnea) after consuming dried puffer fish (also known as globefish) purchased during a recent visit to New York City.
The patients said two friends who consumed the same fish had similar, although less pronounced, symptoms and had not sought care. The Minnesota Department of Health conducted an investigation to determine the source of the product and samples were sent to the Food and Drug Administration (FDA) Center for Food Safety and Applied Nutrition for chemical and genetic analysis.
Genetic analysis identified the product as puffer fish (Lagocephalus lunaris) and chemical analysis determined it was contaminated with high levels of tetrodotoxin. A traceback investigation was unable to determine the original source of the product. Tetrodotoxin is a deadly, potent poison; the minimum lethal dose in an adult human is estimated to be 2–3 mg (1). Tetrodotoxin is a heat-stable and acid-stable, nonprotein, alkaloid toxin found in many species of the fish family Tetraodontidae (puffer fish) as well as in certain gobies, amphibians, invertebrates, and the blue-ringed octopus (2). Tetrodotoxin exerts its effects by blocking voltage-activated sodium channels, terminating nerve conduction and muscle action potentials, leading to progressive paralysis and, in extreme cases, to death from respiratory failure. Because these fish were reportedly purchased in the United States, they pose a substantial U.S. public health hazard given the potency of the toxin and the high levels of toxin found in the fish.