What are the causes of babesiasis and how to prevent?
Babesia is a tick-borne protozoan that lives in the red blood cells of vertebrates such as mammals and birds, A member of the genus Babesia of the subkingdom Protozoa (Apicomplexa), Sporozoasida (Piroplasmida), Babesiidae (Piroplasmida) ). Can be divided into small and large two kinds of insect species, usually smaller than 2.5μm, can cause human Babesiosis.
The parasitic stage of protozoa in the red blood cell of vertebrates is budding proliferation. They continuously rupture red blood cells and free into blood, and then invade other red blood cells to enlarge their infection. After these protozoa containing red blood cells are ingested by ticks, as long as the red blood cells remain intact, the protozoa can develop into a sexual stage in the red blood cells to form zygote, and continue to divide and proliferate to produce a large number of vermicule. Curlida, which escapes from the ruptured intestinal epithelial cells and enters the whole coelomen of the tick, develops a semicircle pear shape via Schizogony when it enters the saliveral gland cells. When this adenozoa is infected with the blood of a tick to a vertebrate, it can be seen from the blood smear of the animal.
How to prevent?
1. Population susceptibility is universal regardless of race, age and gender. Babesia minimus also causes infections and clinical symptoms in immune people, reversing the previous view that people with intact spleens were not infected. People engaged in animal husbandry were infected with occupational tendency.
2. Epidemiological characteristics Since Babes' discovery of Babesia infection in animals in 1888, more than 90 species of the genus Babesia have been known to infect wild and domestic animals. At least three species have infected humans, such as Babesia minimus and Babesia Gibson (B.gibsoni) from North America and B. bibacillus (B. bovis) common in Europe. There are three general patterns of human prevalence, that is, human babesiosis usually occurs after an epidemic among animals. Some domestic animals only appear protozoaemia after infection without clinical symptoms. Although domestic animals do not have the disease, but through the tick vector can be infected with Babesia bicarbacter to human, and after splenectomy and immunodeficiency people are especially susceptible, the special occurrence site of this disease is the farm. The second pattern has nothing to do with these but is caused by rodent microbabesia infection. In the past 30 years, the number of cases of human Babesia has increased, and recessive or subclinical infections have been found, and protozoa have also been isolated from asymptomatic blood donors. The third model is that infective whole blood and frozen red blood cells and platelets can be transmitted to the recipient through blood transfusion. In addition, the mode of mother-to-child transmission of the disease has also been confirmed.
3. Prognosis: Patients with mild or moderate disease should be treated in time, and can be cured without sequelae. Patients with severe hemolysis, renal failure and a history of splenectomy have a poor prognosis. The case fatality rate is about 5%. Protozoaemia occurs in chronic patients and can last from 2 years to several years.