It's time for winter tonics again. On short video platforms, plates of "crystal clear" sashimi, accompanied by "fresh, sweet, crispy, tender, and soul stirring" commentary, stimulate people's desire to pursue novel cuisine. But few people know that behind this "deliciousness" may lurk a deadly threat - liver fluke (scientific name "Clonorchis sinensis"). Today, we will show you the true face of liver flukes. 1、 The "three-step" transmission of liver flukes relies on the "three major hosts+one habit", namely the first, second intermediate host and final host, as well as the habit of eating fresh water fish. Its complete lifecycle strictly follows the order of "first intermediate host (freshwater snail) → second intermediate host (freshwater fish) → final host (human/mammal)"; The habit of eating freshwater fish raw plays a key role in helping liver flukes smoothly transition from the second intermediate host to the final host. Step 1: Hatch liver fluke eggs in the first intermediate host and excrete them through feces. They are then swallowed by freshwater snails in water and begin to hatch inside the snail, initiating asexual proliferation. Step 2: In the second intermediate host, each worm egg undergoes asexual proliferation within the snail and transforms into countless cysticerci that escape from the snail. When the cysticerci encounter freshwater fish in the water, they quickly burrow into the fish's body, and each cysticerci can develop into a cysticercus in its muscle. Step 3: Invasion of the final host through feeding. After the cysticerci mature in the fish, the most critical step is reached: invasion of the final host. But this step cannot be completed by itself, it must have the help of 'benefactors'. People who enjoy eating raw fish slices play a crucial role in completing the life cycle of liver flukes and making significant contributions to their population growth. The raw fish slices that appear crystal clear on the surface may not be clean under a microscope. After the raw fish slices containing cysticerci enter the human digestive tract, the cysticerci detach and become larvae under the stimulation of digestive fluids. The larvae crawl into the hepatic and biliary ducts along the intestine and settle here. After one month of development, they become adults and begin to lay eggs. Thus, the complete life cycle of liver flukes is completed. 2、 The hidden "gradual" harm under umami flavor can cause gastrointestinal symptoms such as abdominal pain, diarrhea, and fatigue in the first 1-2 months of infection. If there are not many infected insects, there may be no obvious symptoms. As adult insects parasitize in the bile duct for a long time, they will continue to stimulate the bile duct wall, leading to bile duct wall hyperplasia, bile duct stenosis, bile stasis, and ultimately causing chronic cholecystitis and gallstones. Adult liver flukes can survive in the human body for 20-30 years. Long term parasitism can cause sustained damage to the liver and biliary system, and the degree of harm increases with the time of infection and the number of parasites, ultimately leading to cholangiocarcinoma. In 2009, the International Agency for Research on Cancer, a subsidiary of the World Health Organization, listed Clonorchis sinensis as a clear carcinogen. Faced with the cumulative damage caused by liver flukes, we should neither take chances nor worry excessively. We can go to a disease control institution or a specialized outpatient clinic in a hospital for fecal egg testing to make a clear diagnosis. If infected with liver flukes, taking deworming medication under the guidance of a doctor can eliminate the parasite. 3、 Scientific prevention and control to protect the liver. In addition to humans, there are other fish eating mammals in nature, such as cats and dogs, which can serve as the final hosts of liver flukes. Therefore, liver flukes are also widely distributed in nature. The purpose of preventing liver flukes is to ensure people's health, so instead of eliminating liver flukes and their hosts from nature, it is better to block the invasion of liver flukes into the human body. The most crucial measure is to control your mouth and refuse the temptation of raw food. Liver flukes are not resistant to high temperatures, and as long as they are cooked, they can kill the cysts in fish meat and achieve true cleanliness. At the same time, it is advocated to separate raw and cooked kitchen utensils to keep risks away from the dining table; Secondly, standardize the aquaculture industry to reduce the infection of farmed fish from the source; Finally, it is important to manage human and animal feces to prevent contamination of water sources by insect eggs. Eat clean fish, be a person with a clean liver, and stay away from the threat of liver flukes! Author: Zhu Tingjun from the Institute of Parasitic Diseases (Xinhua News Agency)