As Western food, Japanese and Korean cuisine becomes more and more popular in China, more and more people are beginning to like to eat raw, sashimi, raw shrimp are already everywhere, many people think that this way to eat healthier. But you know what? Aquatic products such as raw fish are easily contaminated by parasites.
Estimates by the WHO Reference Group on the Epidemiology of the Burden of Foodborne Diseases (2015) identified four foodborne trematodes as significant causes of disability, resulting in a total of 200 000 diseases and more than 7000 deaths per year, resulting in more than 2 million disability-adjusted life years globally. The Food and Agriculture Organization of the United Nations (FAO) lists 10 important zoosites that humans and fishes are co-infected with, and lists parasites as the first biohazard factor in aquatic products.
What are the parasites WeChat for seafood such as raw fish and shrimp? What is the harm?
<h1>Chondridylus</h1>
The causative agent of Sinocrochydosis is CIonorchiosis sinensis, which prefers to parasitize the host's hepatobiliary system, so it is also called hepatic flukes.
The first intermediate host of Chinese mycodystis is freshwater snails, and the second intermediate host is general freshwater fish and shrimp, such as grass carp, bluefish, carp, bream, crucian carp, etc. If you eat raw or unripe freshwater fish and shrimp containing liver fluke cysts, it is easy to be infected.
At present, there are about 10 million infected people in China, of which Guangdong is estimated to account for 5 million.
The harm of hepatic fluke disease is mainly liver damage in patients. Can cause cholangitis and cholangiohepatitis. Chronic infection can present with multiple intrahepatic stones. Severely infected people can cause liver stiffness and ascites in advanced stages, and even death. There is growing evidence that hepatic fluke infection can increase the prevalence of primary hepatobiliary duct carcinoma. Quercetones are the drug of choice for the treatment of hepatic trematodiasis.
<h1>Xenocephalus</h1>
Anisaki larvae are a type of parasite that is currently harmful to humans in seafood, mainly distributed in the North Atlantic, North Pacific and the Sea of Japan.
It can infect hundreds of species of marine fish, the most susceptible species are cod, salmon, sardines, anchovies, tuna, catfish, bamboo collins, squid and striped fish. In addition, squid, which is not a fish, is also one of the hosts of Xenocephalus. In marine fish, Xenocystis gradually develops into infectious stage III larvae that enter the digestive system of marine mammals through the process of being ingested by marine fish.
Isaacular nematode larvae are mostly parasitic on the abdominal wall and organ surface of fish, people are mainly infected by accidentally eating fish containing iscus nematodes larvae, and the human body will produce severe abdominal pain, nausea, vomiting, diarrhea and other symptoms after infection with iscus nematodes larvae, and anaphylactic shock occurs in severe cases. The high rate of infection of Xenocephalus larvae in marine fish is one of the main risk factors for human infection with Xenohads.
<h1>Broad-segmented taenia</h1>
Plerocercoid is not the name of a parasite. It is a general term for the larvae of certain species of tapeworms in a developmental stage known as the "mid-taenia stage". Although not yet fully developed, Schizophal larvae are already quite similar in appearance to adults, and because of their high mobility, Schizophal larvae often cause more damage to parasitic hosts than their adults.
Schizophal larvae can infect freshwater fish, marine fish and amphibians, the most susceptible species are pike, river cod, river bass, salmon, pink salmon, salmon, barracuda, white-eyed bass, brook spotted salmon, sea bass, rainbow trout, red-eyed fish, roundhead, salamander, carp and yellow striped fish, especially salmon and salmon in the Sea of Japan.
According to literature reports, since 1894, there have been more than 180 cases of infection with Schizocephalus in the Sea of Japan due to raw salmon and other seafood. In recent years, there have been increasing cases of human infection with Taenia macrocephalus due to raw food imports of marine fish.
Fish broad-segmented schizothia can parasitize freshwater fish and marine fish, while a large proportion of imported aquatic products are marine fish, especially in Japanese waters, the probability of marine fish infected with broad-segmented schizocephalus is high, which is related to the return of marine fish in this area.
Once a person eats raw or unripe fish or amphibians containing schizophrenia, for example, eating raw fish and sashimi, or using a small amount of salted, smoked fish meat or fish eggs, juice soaked fish, etc. are very susceptible to infection.
After infection with human body, Schizocephalic larvae can develop into adult worms in the intestine, and a small number of people may have tiredness, fatigue, numbness of limbs, diarrhea or constipation and hunger, salt consumption and other symptoms, and serious infections can block the intestines and cause intestinal perforation. Aquatic products containing Schizocephalus are one of the high risk factors for human infection with Schizocephalus.
<h1>Lung flukes</h1>
Lung fluke disease, also known as cohodigodiasis, is a disease caused by the migration of larvae of weedys, adults in tissues and organs, channeling, colonization or larvae of Stustudiana spp.
Cysticercetes are mainly parasitic in crustaceans, and the most susceptible species are brook crabs and cockroaches. Freshwater crabs are the second intermediate host for cohody trematodes, and both humans and animals can be infected with thixoplasmasis due to raw and semi-raw or salted brook crabs.
In 1998, China's Liaoning Province imported North Korean river crabs, causing more than 600 people to be infected and breed trematodes. Raw or semi-raw-fed brook crabs and cockroaches are the most important causes of infection and breeding of tremazoomas in populations. Zhejiang and other places in China have the habit of eating drunk crabs raw; in the mountains of northern Fujian, it is spread to eat raw crabs, and these eating methods are easy to infect with lung trematodiasis.
Systemic diseases caused by lung flukes, mainly lung lesions, the main clinical manifestations are cough, coughing up rust-colored or peachy sputum, chest pain, hemoptysis and other symptoms. Because the insect body not only has great damage to the tissue, but also has the characteristics of wandering, it can cause new and old lesions of any tissue and organ in the body, so the clinical manifestations are extremely complex.
<h1>Jaw-mouth nematodes</h1>
Gnathostoma is a large family of parasites, with a total of 13 large families, of which, Echinaceous El nematode, Du's jaw-mouth nematode, Japanese jaw-mouth nematode, Malay jaw-mouth nematode are the main pathogenic species in Asia, the most infected fish are freshwater fish, the most susceptible species are eel, loach and mullet.
Humans are mainly infected by raw or ingested raw or ingested raw fish meat containing stage III larvae of the jaw-mouth nematode. Humans are not suitable hosts for jaw-mouth nematodes, and the vast majority of insects obtained from humans are stage III larvae or immature adults. Human damage is mainly caused by mechanical damage caused by larval migration and inflammation, toxin stimulation and allergic reactions around the worm body.
In addition to mammals, some waterfowl also prey on fish, frogs or snakes infected with jaw-mouth nematodes. In waterfowl, the larvae of the jaw-mouth nematode do not grow into adults, but still have the ability to infect other animals. Therefore, frogs, snakes, waterfowl, cats, dogs, pigs, and other wild animals may also become a source of infection.
The hermitage mode of jaw-mouth nematodes in the human body can be divided into two types: resting type and migratory type, and the causative site is extremely extensive, almost all over the body, including the forehead, face, pillow, ears, eyes, fingers, throat, chest, abdomen, penis and cervix. The clinical types caused can be divided into two types: cutaneous and visceral jaw-oral nematode disease, and so far, there is no specific drug to treat this disease.
<h1>How can I prevent parasite infestation? </h1>
The most effective approach is to try not to eat aquatic products raw, especially aquatic products of unknown origin, because of unknown origin, its growth environment, transportation and storage conditions can not effectively ensure safety, and the risk of parasites is also greater.
Try not to eat freshwater and aquatic products raw. Because the risk of parasites in freshwater aquatic products is generally greater than that of marine products, and the parasites in freshwater aquatic products can generally be parasitized directly in the human body, the risk is also greater.
Eat aquatic seafood as fully cooked as possible before eating.
If you want to eat it raw, try to eat it at a regular restaurant.
Resources:
Xia Lizhao. Epidemiology of parasitic diseases in China[J].Journal of Disease Control,1997,(3):169-172.
Xia Lizhao. Epidemiology of parasitic diseases in China[J].Journal of Anhui Medical University,2000,(1):1. DOI:10.3969/j.issn.1000-1492.2000.01.001.
[3] CDC.Parasites - Gnathostomiasis (Gnathostoma Infection)
[4] Thomas Fürst, Jennifer Keiser, Jürg Utzinger. Global burden of human food-borne trematodiasis: a systematic review and meta-analysis.2012， 12（3）：210–221.
Xue Yajuan,Hui Qingfa. Research progress on foodborne parasitic diseases[J].Journal of Yan'an University (Medical Science Edition), 2006,(2):3-4. DOI:10.3969/j.issn.1672-2639.2006.02.002.
Zhu Yanqi, Zhou Xinli, Zhang Yongnian, et al. Risk factors of parasitic infection in aquatic products[J].International Journal of Medical Parasitic Diseases,2014,(5):301-306. DOI:10.3760/cma.j.issn.1673-4122.2014.05.012.