Raw fish in Thailand: dangerous!

Recently, the Algemeen Dagblad once again reported on the annual National Herring Test. Always fun to read and it makes my mouth water. If I had to name something I'm in here Thailand from the Netherlands, it is a delicious, fat new herring, fresh from the knife.

Foreign guests, whom I used to want to treat to a herring in Amsterdam, for example, often turned their noses up at eating this raw fish.

Raw fish

The Japanese sashimi also consists of raw fish, which I like to eat as an appetizer in a Japanese restaurant. In the Netherlands, a visit to a Japanese restaurant was something for special occasions, because it is quite pricey, especially when it comes to sashimi. Fortunately, here in Thailand, sashimi is also on the menu of Japanese restaurants and at a reasonable price.

Thai cuisine also has dishes with raw fish and I am referring in particular to a dish that is very popular in Isaan. It is called Som Pla, which is made from pieces of raw (river) fish mixed with garlic, salt, steamed rice and some other spices. It is then divided into small portions in plastic bags, after which it is placed in the tropical heat of the sun for about three days. This rotting process, fermentation with a nice word, then gives the special taste to Som Pla. In an interview with a villager, a woman said, “Yes, it smells like hell, but it tastes heavenly. When I see it, I have to eat it, it's almost an addiction.”

Liver cancer

Now there are more fermented dishes in Isaan, which I detest because of the smell alone, but eating this fermented raw fish can also have deadly consequences. This river fish contains quite a few parasites, which accumulate in the body in the liver and – after regular consumption of this dish – can lead to bile duct cancer, which is fatal.

This type of cancer is rare in other countries, but most of the 70 people who die of liver cancer every day in Thailand have contracted this bile duct cancer. This says Dr. Banchob Sripa, Head of the Tropical Diseases Research Laboratory at Khon Khaen University. “It is the most persistent and deadly cancer in the region,” he adds. Dr. Sripa has been campaigning for almost 30 years against this parasite, the liver fluke, which is also widespread in Canbodja, Laos, Vietnam, parts of China, Korea and Siberia. According to the World Health Organization (WHO), more than 67 million people are infected, of which 9 million in Cambodia, Laos, Vietnam and the northeast of Thailand.

Dr. Peter Hotez, President of the Sabin Vaccine Institute, a non-profit organization in America that does a lot of research on neglected diseases, describes liver fluke as one of the leading causes of cancer that almost no one has ever heard of. The vast majority of infections occur in men, who can contract this cancer by the time they are 40 to 50 years old.

Cooking or baking the raw fish would completely eliminate contamination. However, the fight against liver fluke is undermined by the deep-rooted love of mostly villagers in poor regions for this sour and smoky tasting dish, as it has been eaten for many generations.

Deadly

Liver fluke is only found in fresh water, but not everywhere. The contamination by this parasite in Bangkok, for example, is negligible. The liver fluke is transmitted by faeces in rural areas without proper sanitation and uses snails, fish, cats and humans as hosts. There is a lot of information about the dangers of this parasite, but the population thinks it's not too bad: "It won't happen to me".

The lethal effect of eating this contaminated raw fish increases over time in the same way that too much alcohol can damage the liver. Heavy drinkers are at increased risk of contracting the cancer if they are already infected by the liver fluke.

In Laos, 1 to 5% of people infected by the parasite are diagnosed with cancer. Liver cancer is also common in Laos, Vietnam and Cambodia. Dr. Banchob estimates that about 10% of the Laotian population is infected by this parasite.

Poor regions

Dr. Hotez says the parasite is similar to other worm species, which receive little attention because it hardly affects the "wealthy" urban population. Although Thailand can be regarded as a middle-class country, there are still many very poor regions where neglected tropical diseases are rampant. Dr. Hotez says: “We have the technology to make vaccines, but we lack the necessary funding.

Dr. Cherdchai Tontsirin, a surgeon in Khon Kaen who has operated on many liver cancer patients, blames the Thai government for the persistence of this disease. However, it has never been taken seriously, because it only occurs in the poor regions in the North and Northeast.

For the above story I used an article in the International Herald Tribune and when I finished it, Reuters also came up with an article about this disease, from which I took some additions.

Medicine

“Everyone over the age of 30 will have an annual faecal examination to detect eggs of this parasite. Those who are infected will be treated with drugs,” said Pongsadhorn Pokpermdee, health economist and deputy chief of public health for Northeast Nongbualanpoo province.
“For those older than 40 who are infected, an ultrasound is done to detect a possible tumor at an early stage. Any tumor is then surgically removed.

As a medicine, Praziquantel is then provided free of charge, which can get rid of all worms and eggs, but it only solves the problem if one stops eating this contagious fish dish.

Time will tell if it helps, but as mentioned in the story, many people like the dish with raw fish and will continue to eat it. By the way, search Som Pla in Google and you will see the recipe for this dish, almost as described at the beginning of this story. After the fermentation, however, the mixture of fish, herbs, rice is fried in oil, which means that contamination is no longer an important addition.