Specific diseases classified as infectious include parasitosis. It is caused by special parasites that have adapted to life in or on the human body, feeding and multiplying in it or with its help. In this case, a person can be an intermediate and definitive host for the parasite (that is, either eggs and larvae or adults develop in the body). Depending on the type of parasite and the location of the lesion, many diseases caused by them can be identified. The most common is helminthiasis - a disease caused by the parasitism of a special type of worm.
Parasites: different types of helminths in the body
The largest group of parasites that can live in the human body are various types of worms, both flat and round. They belong to a separate group of diseases, which doctors collectively call "helminthiases. "Each parasite of this group has its own route and method of infection, characteristics of its life cycle and the development of clinical manifestations, as well as its treatment methods. In addition, each parasite is capable, due to its life cycle, of causing certain complications. The most common parasites that can infect people are pinworms and roundworms, trichinella, pork or beef tapeworms.
Types of parasites and characteristics of the course of infection
If there are signs of indirect helminth infection, it can be assumed that one type of parasite lives in a person's body. However, for the treatment to be effective and correct, it is important to know the specific type of parasite, as well as the organs and systems affected by it. To do this, it is important to undergo a full examination and pass several tests. Why is this necessary?
First of all, it is important to remember that different types of parasites live in the body of the host in a larval state (if someone is their intermediate host) or a sexually mature individual (if the final host). In this case, the therapeutic effect, depending on what stage the worm is a parasite, may be different, as well as the parasite's habitat.
Parasites such as echinococcus will be dangerous to humans in the larval stage. Larvae, in the form of round cystic capsules filled with toxic fluid, infect the lungs, liver, kidneys or brain. In this organ, for several months or years, echinococcal cysts grow, inside which there are larvae. But such types of parasites as pinworms live in the body in the form of sexually mature individuals. The female crawls out of the rectum to lay millions of eggs, which are released into the external environment with feces.
Depending on the type of parasite, as well as the body's individual response to them, the location of the lesion, and the body's response, clinical manifestations range from asymptomatic to significant and severe, even fatal. It should also be remembered that there is a variation of mixed infection, when several types of parasites live simultaneously in the body.
How do parasites enter the body?
The way parasites enter the body can be different. Infection often occurs when parasite eggs enter the human body with contaminated food or water, from dirty hands, as well as through damaged skin, through insect bites. Often, worm eggs remain for a long time in the form of eggs in the soil, water or on the surface of objects. Entering the body through hands, food or water that does not undergo proper treatment, the parasite penetrates into the body, where the eggs quickly ripen, and larvae (intermediate versions of the parasite) or mature individuals emerge from them.
It is important to remember that parasites in the body cause serious harm, even if there are no obvious signs of damage. First of all, they eat their host, denying it some nutrients, vitamins and minerals. In addition, parasites in the body dramatically increase the allergenicity of the body, overstimulating the immune system, which threatens the development of spontaneous skin and other allergic reactions to products and substances that were quite common before.
The body does not remain indifferent to the penetration of worms into it, especially if it is soft tissue and internal organs. Thus, a protective inflammatory capsule is formed in the muscles and tissues, separating the parasite from the healthy tissue. This leads to the formation of parasitic cysts, often filled with worm waste. Often the body also reacts to the introduction of parasites with digestive disorders, if these are worms living in the intestines, changes in appetite, fluctuations in body weight and exacerbation of chronic diseases.
Do not think that the problem of parasites is only relevant for people from the poorest countries and those who are careless about hygiene. The prevalence of helminths is amazing; according to the WHO, it is comparable to diseases such as ARVI and influenza. Therefore, it is necessary to undergo regular examinations and rule out parasitosis.
What type of parasite testing is required?
Many patients mistakenly believe that a single test for parasites (stool or smear from the perianal area), which shows a negative result, is a guarantee of the absence of parasites in the body. However, in reality everything is not so, and this result does not mean anything. First, parasites can be extraintestinal, living in other organs and tissues, and then their eggs or larvae do not end up in the feces.
Second, when taking a test for parasites, there may be periods of the parasite's life when it still or no longer lays eggs. And thirdly, there is a risk that all the conditions for analysis are not met, and therefore eggs are not found in the prepared sample.
Therefore, if we talk about intestinal worms, when the test for parasites is prescribed, stool is taken three times at certain intervals to confirm the presence or absence of parasites. Only this technique can confirm or deny the diagnosis with a probability of up to 90%.
More indicative in this regard is the analysis for parasites taken from the vein, with the determination of antibodies to specific worms. If the body has been in contact with a parasite recently, there will be class M antibodies to it, which will identify the pathogen. The long-term presence of the parasite will also produce antibodies of another class.