1, what is schistosomiasis?
Schistosoma japonicum is a very small insect, about 2 cm long, which can be divided into female and male insects. An adult has suckers in its mouth and abdomen. Because it lives in the blood vessels of humans or other mammals and lives on blood, it is named Schistosoma japonicum. Schistosoma japonicum is distributed in China and was first discovered by Japanese, so it is called Schistosoma japonicum.
2. What is the life history of Schistosoma japonicum?
The life history of Schistosoma japonicum has six stages, namely, adult stage, metacercaria stage, cercaria stage and larval stage. Schistosoma japonicum is parasitic in the mesenteric vein of human or mammal (the ultimate host). The eggs produced by mating of male and female insects penetrate the intestinal wall and fall into the intestinal cavity, and are excreted with feces. Eggs hatch miracidium in water, drill into Oncomelania hupensis (intermediate host) and develop in its body. After two generations of asexual reproduction, cercaria formed. The cercaria ran out of the snail and swam on the water. When it meets humans or mammals, it will quickly enter their skin and become cercaria.
3. How did people get infected with schistosomiasis?
People are infected with schistosomiasis by touching water containing Schistosoma cercariae (called epidemic water). There are two main types of infection: one is productive infection, such as weeding, herding cattle, shrimp fishing, water transportation, reed cutting, flooded irrigation, flood control and so on. The second is life-related infection. Such as swimming, paddling, wading and washing clothes in rivers, ditches and lakes containing cercariae.
4. Who is most susceptible to schistosomiasis in what season?
Every schistosomiasis patient may be infected. The more opportunities, times, times, ways and body surface areas people have to contact with the epidemic water, the greater the chance of infection. Schistosomiasis can be infected all year round. April-August is the peak of infection every year, and acute schistosomiasis occurs at this peak.
5. How does schistosomiasis endanger human health?
Larvae, adults and eggs of Schistosoma japonicum can all cause harm to human body, but the pathological changes caused by eggs are the most serious. A large number of egg deposits actively cause liver cirrhosis, and then hepatosplenomegaly, ascites and esophageal varices appear, such as varicose veins rupture, which can lead to massive bleeding in the upper digestive tract. Diseases of rectum and colon caused by eggs will cause intestinal wall ulceration, bloody stool and intestinal stenosis. The severity of schistosomiasis and infection is related to the strength of human disease resistance. In short, schistosomiasis will seriously affect production and life, seriously affect growth and development, and even endanger life.