24 What are the conditions for schistosomiasis to infect humans?

What kind of parasite is schistosome?

The conditions that must be met for schistosomiasis transmission do not include mosquito parasitism.

Schistosomiasis is a chronic parasitic disease caused by Schistosoma schizosomes, which is mainly endemic in 73 countries in Asia, Africa and Latin America, affecting about 200 million people. There are two main types of schistosomiasis, one is intestinal schistosomiasis, which is mainly caused by Schistosoma mansoni and Schistosoma japonicum; The other is urinary schistosomiasis, which is caused by Schistosoma haematoidosis. The main epidemic in our country is Japanese schistosomiasis.

If there are specific antibodies in the serum of schistocyst patients, including IgM, IgG, IgE, etc., if the subject does not have a pathogen**, and the specific antibodies are positive, it is of great significance to determine the diagnosis; If the pathogen is already ** and the specific antibody is positive, it cannot be determined that the person tested still has adult parasites in the body.

After **, the specific antibodies can still be maintained in the body for a long time. Because the post-antibody remains in the host for a long time, its positive results often cannot distinguish between current infection and previous infection, and it is not easy to evaluate the efficacy.

Circulating antigens are macromolecular particles emitted into the host body by living insects, mainly excretion, secretion or epidermal exfoliation of insects, which have antigenic characteristics and can be detected by serum immunological tests. From the perspective of rationality, the detection of CAG has its own advantages, which can not only reflect the activity of infection, but also evaluate the efficacy and estimate the species.

Prevention:

1. Do not swim or play in lakes, ponds, and canals where snails are distributed.

2. For those who are inevitably exposed to infected water due to production and life, they can apply protective ointment before contacting infected water to prevent schistosomiasis infection.

3. After contact with the infected water, it is necessary to go to the local blood prevention department in time for necessary inspection and early **.

Answer]: B Concomitant immunity and carrier immunity belong to the non-elimination immunity type, and the type of immunity produced by human land chain hand infection with Schistosoma spp. belongs to the concomitant immunity; Infection of the host by the malaria protozoa can induce carrier immunity.

Answer]: e Analysis: There are three necessary conditions for the transmission of schistosomiasis, that is, the eggs are covered with the feces of the feast, and the snails are present and come into contact with the infected water of humans or animals.

Cercariae can invade the human body through the oral mucosa and ** and cause infection. Master the knowledge points of "Japanese schistosomiasis".

It can infect humans on a large scale because of the transmission route, and most of our usual parasites are transmitted by fecal-oral transmission, transmitted through the feces of live animals and eaten by intermediate hosts.

Although schistosomiasis can also be transmitted through infected feces of living poultry, including snails. The main reason for the real widespread infection is that it can be transmitted directly through water sources.

According to the different forms, they can enter the body by drinking water infected with schistosomes, and can also invade the human body through ** after swimming and bathing in the water source infected with schistosomes.

And water is an inseparable part of human existence. Therefore, in the early days of the founding of the People's Republic of China, there was a large area of schistosomiasis. Later, after a series of efforts, schistosomiasis was basically eradicated in China.

Answer]: A Analysis: The cercariae in the eggs of the acute ovaria nodules of schistosomiasis are still alive, and the body's response to them is mainly the infiltration of a large number of acidophilic coarse clump acidocytes, while the epithelial cells of the radial fibrillary cherry row appear in the late acute ovar nodules.

Master the knowledge points of "schistosomiasis stool macro".

Answer]: A test center] Schistosomiasis.

Analysis] The acute egg nodules of schistosomiasis are still alive, and the body's response to the occurrence of spikes is mainly a large number of eosinophil infiltration; In the late stage of acute worm egg nodules, radial epithelial cells appear in the ruler Kaiye.

Answer]: A cercaria, larvae, adults and eggs can cause damage to the host, but the lesions caused by the infiltration of cherry eggs by the insect chain are the most serious, and the harm to the body is also the greatest. Schistosomiasis eggs cause major lesions to the human body, and the basic pathological changes are egg nodules, which are manifested as clusters of eggs in the liver, intestine and lung tissues, which lead to diffuse fibrosis in the tissues of the tissues in the later stage.