Recently, a man in Nanning, Guangxi, was diagnosed with clonorchiasis and taeniasis after eating raw foods such as raw fish slices and undercooked beef. After being hospitalized to remove the parasites, doctors discovered a parasite measuring up to 5 meters long still alive inside his body. This serves as a reminder for friends who love to eat raw meat: while you can indulge your cravings, you must do so in a healthy and safe manner to avoid getting parasites. Experiments have shown that Clonorchis sinensis metacercariae in a fish slice about 1mm thick will die in one second in 90°C hot water, within 3 seconds at 75°C, and all will die within 6 seconds and 15 seconds at 70°C and 60°C, respectively. However, when grilling, roasting, scalding, or steaming a whole fish, the metacercariae may not be completely killed due to insufficient temperature, inadequate time, or fish that is too thick. This shows that in addition to eating less raw meat, cooking for a sufficient amount of time is necessary to kill parasites. Now, let's learn about the presence of parasites in some animals:
Frog
Although the country explicitly prohibits the consumption of frogs, some people still violate this ban. In fact, from a health perspective, frogs should not be eaten either. According to Professor Qinmin Gu, frogs are the second intermediate host of *Spirometra mansoni*. When eating frog meat, if the live larvae of *Spirometra mansoni* enter the human body, they can cause sparganosis in the eye, subcutaneous sparganosis, oral and maxillofacial sparganosis, cerebral sparganosis, and visceral sparganosis. These conditions can damage human tissues, leading to symptoms such as blindness, coma, skin itching, and even paralysis. Therefore, although frog meat is delicious, it should not be eaten.
Snake
Snakes eat frogs and are paratenic hosts for *Spirometra mansoni*. They can also contain the larvae of this parasite. If not handled properly, eating them can also lead to the diseases mentioned above. Experts have found thousands of parasites in the subcutaneous tissue, muscles, and abdominal cavities of snakes. Of course, snakes can be used for medicinal purposes, but their medicinal and culinary uses are vastly different. For example, medicinal snake bile has strict and precise regulations regarding its source, preparation method, dosage, and administration. In contrast, snake bile consumed at the table is prized for being "fresh," meaning it is taken directly from the snake's abdomen. Furthermore, experts point out that while fresh snake bile contains components that aid digestion, it also contains many toxic substances excreted by the liver and parasites such as *Gnathostoma hispidum*. Blindly consuming fresh snake bile can easily damage internal organs and induce liver or kidney failure.
Freshwater Fish and Shrimp
There is a folk saying, "eat crabs raw and eat shrimp live," but this is not scientifically sound. According to Professor Gu, freshwater fish and shrimp can be parasitized by the metacercariae of *Clonorchis sinensis*, which can cause clonorchiasis (also known as liver fluke disease), with symptoms similar to hepatitis. Freshwater crabs can be parasitized by *Paragonimus westermani*, leading to paragonimiasis, with symptoms similar to tuberculosis, such as coughing and bringing up rust-colored sputum. If the parasite enters the human brain, it can easily lead to stroke and coma. Therefore, freshwater fish and shrimp must be thoroughly cooked, and it is best to avoid eating them raw, such as with dishes like sashimi.
Marine Fish
Some marine fish may be parasitized by *Anisakis*, but the situation is not as severe as with freshwater fish. When this parasite enters the human body, it can cause symptoms such as diarrhea. In severe cases, it can lead to intestinal erosion and ulcers.
Fruits and Vegetables
According to Professor Gu, in addition to the animals mentioned above, special attention must be paid to washing fruits and vegetables thoroughly during the summer, as their surfaces may contain eggs of roundworms or whipworms, which can develop into adult worms in the human intestine, causing ascariasis or trichuriasis. Also, water chestnuts and water caltrops may have metacercariae of intestinal flukes on their surface. Consumption can lead to intestinal fluke infection, with symptoms such as abdominal pain and intestinal obstruction.
Snail Meat
There are many types of snails, and they grow in complex environments. In some places, eating snail meat is a custom. Some snails contain parasites, but whether they are harmful to humans depends on their stage of development. For example, marsh snails, pond snails, and bean snails are the first intermediate hosts of *Clonorchis sinensis* and are not very harmful to humans after consumption. However, after testing purchased jade snails, experts found that 30% were infected with *Angiostrongylus cantonensis* larvae. This can cause headaches, nausea, vomiting, fever, intermittent drowsiness or lethargy. A few patients may experience coma, agitation, mental disorders, and a stiff neck. Some patients may have various types of sensory abnormalities in different parts of the body, such as head, trunk, and limbs (e.g., burning, numbness, pain). Some patients may experience visual impairment or blindness. Half of the patients may have an enlarged liver. Therefore, eating snail meat raw is not scientifically sound.