KUCHING: Fish is a vital source of protein for many people around the world, and it is an essential part of a healthy diet.
However, certain species of fish can be deadly if not prepared and consumed correctly.
A recent incident of pufferfish poisoning has raised concerns over the dangers of consuming pufferfish and the risks associated with purchasing food from unknown sources.
In light of this, the New Sarawak Tribune approached a medical expert, Dr Azizul Idris, for his insights into the matter, emphasising the need for caution when consuming potentially hazardous foods.
The occupational health doctor at KPJ Kuching Specialist Hospital said the most common fish that can be deadly through ingestion is pufferfish, also known as ikan buntal or ikan buntal pisang.
It is also known as “fugu” in Japanese.
Pufferfish, he noted, which is commonly found in Malaysia, contains tetrodotoxin, a toxin that attacks the nervous system and can cause a range of symptoms that can be fatal.
He said other types of sea creatures that can cause poisoning are blue-collared octopuses, which can be found in Australia but are not seen in Malaysia.
Meanwhile, other sea creatures that can cause poisoning in Malaysia are jellyfish, he added, but this is not mainly through ingestion but more through stings.
“Ciguatera fish poisoning (CFP) can also occur if we consume reef fish that is contaminated with cigatoxins.
“Cigatoxins are produced by algae, and large fish can be contaminated with cigatoxins such as snapper, barracuda, grouper, Spanish mackerel, and morel eels.
“However, this poisoning is not directly due to toxins in the fish itself, but contamination from the algae that produce ciguatoxins,” he said.
Dr Azizul said there have been several cases of pufferfish poisoning in Malaysia, some of which have resulted in fatalities.
CFP cases were also seen but much less than pufferfish poisoning. The latest case was reported in Sabah in 2019, he said, but fortunately, the patient recovered.
He said most of the CFP poisoning occurs in Malaysia were due to the ingestion of infected red snapper.
The symptoms, he pointed out, include numbness of the mouth, facial and limb numbness, feelings of pins and needles, salivation, nausea, vomiting, diarrhoea, abdominal pain, muscle weakness, difficulty in speech, respiratory muscle paralysis, heart dysfunction, coma, and even death.
Pufferfish poisoning symptoms, he said, are mostly attributed to its tetrodotoxin, a toxin that attacks our nervous system.
Thus, the symptoms are mostly related to symptoms of the nervous system and related to the time of toxin ingestion.
High concentrations of tetrodotoxin can be found in the liver and intestines of pufferfish. Within 15 to 20 minutes of ingestion, the first symptoms that appear are mostly numbness of the mouth area (lips and tongue).
However, these symptoms may be delayed in some individuals and can occur up to 20 hours after ingestion.
“These symptoms then developed into facial and limb numbness and the sensation of needles and pins.
“Salivation, nausea, vomiting, and diarrhoea with abdominal pain can develop early.
“Muscle weakness and difficulties in speech and ventilation can occur four to 20 hours after ingestion.
“Respiratory muscle paralysis can develop, and finally, heart dysfunction can develop that leads to a slowing of the heartbeat and an irregular heart rhythm.
“They can develop comas due to brain dysfunction. Death can occur within four to six hours without supportive treatment,” said Dr Azizul.
However, there is no specific treatment for pufferfish poisoning, and the only course of action is supportive treatment to support failing organs and prevent death.
This, he said, may require intensive care unit (ICU) care as the symptoms can worsen quickly and a ventilator may be necessary for breathing.
Meanwhile, decontamination of the stomach may be useful, but only if the patient has not already vomited, and the injury to the gastrointestinal tract must also be considered.
But then, how can one ensure that they are preparing and cooking fish safely in order to avoid the risk of poisoning?
In Japan, where pufferfish is considered a delicacy, special training and a licence are required to prepare it safely.
The training takes three years, and only trained chefs can prepare pufferfish.
However, in Malaysia, Dr Azizul said there are no chefs trained to prepare pufferfish safely, and it is strongly advised to avoid consuming it.
Therefore, he advised that it is recommended that all populations avoid consuming pufferfish, as there are no licensed chefs trained to prepare it safely in Malaysia.
Towards this end, awareness and education campaigns should also be implemented to prevent the consumption of pufferfish and other sea creatures that can cause poisoning.
