Specific diseases classified as infectious include parasitosis. They are caused by special parasites that have adapted to life in or on the human body, feeding and reproducing in it or with its help. In this case, a person can be both an intermediate and definitive host for parasites (that is, eggs and larvae or adult individuals develop in the body). Depending on the type of parasites and the location of the lesion, many diseases caused by them can be identified. The most common are helminthiases, diseases resulting from the parasitism of special types of worms.
Parasites: various 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 "helminthiasis". Each parasite of this group has its own routes and methods of infection, characteristics of the life cycle and development of clinical manifestations, as well as methods of treatment. Furthermore, each parasite is capable, due to its life cycles, of causing specific complications. The most common parasites that people can get sick from are pinworms and roundworms, trichinella, porcine or bovine tapeworms.
Types of parasites and characteristics of the course of infection
If there are indirect signs of helminth infection, it can be assumed that one of the types of parasites lives in the person's body. However, for the treatment to be effective and correct, it is important to know the specific types of parasites and which organs and systems are affected. To do this, it is important to undergo a comprehensive examination and pass a series of tests. Why is it necessary?
First of all, it is important to remember that various types of parasites live in the host's body in the larval state (if the intermediate host is a person) or as a sexually mature individual (if the final host). In this regard, the therapeutic effects, depending on the stage in which the parasitic worm, can be different, as well as the habitat of the parasite.
Types of parasites such as echinococcus will be dangerous to humans in the larval stage. The larvae, in the form of a round cystic capsule filled with a toxic liquid, infect the lungs, liver, kidneys or brain. Inside these organs, for many months or years, an echinococcal cyst grows, inside which the larvae are located. But types of parasites such as pinworms live in the body in the form of sexually mature individuals. Females crawl out of the rectum to lay millions of eggs, which are released into the external environment with feces.
Depending on the type of parasites, the individual reactions of the organism to them, the location of the lesion and the organism's response, the clinical manifestations vary from asymptomatic to pronounced and severe, up to death. It is also worth remembering that there are variants of mixed infections, when several types of parasites live in the body at the same time.
How do parasites enter the body?
The ways in which parasites enter the body can be different. Infection often occurs when the eggs of the parasite 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, in water or on the surface of objects. Entering the body through hands, food or water that has not undergone proper treatment, parasites penetrate the body, where the eggs rapidly mature 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 damage, even if there are no obvious signs of damage. First they eat their host, depriving it of some nutrients, vitamins and minerals. In addition, parasites in the body significantly increase the allergenicity of the body, overstimulate the immune system, which threatens the development of spontaneous skin and other allergic reactions to previously familiar products and substances.
The body does not remain indifferent to the penetration of worms, especially if it concerns soft tissues and internal organs. Therefore, protective inflammatory capsules form in muscles and tissues, separating the parasite from healthy tissues. This leads to the formation of parasitic cysts, often filled with waste products from the worms. Often the body reacts to the introduction of parasites even with digestive disorders, if these are worms living in the intestines, changes in appetite, weight fluctuations and exacerbation of chronic diseases.
Do not think that the problem of parasites is relevant only to people from poorer countries and those who are not very attentive to hygiene. The prevalence of helminths is surprising and according to the WHO is comparable to diseases such as ARVI and influenza. Therefore, it is necessary to undergo regular examinations and exclude parasitosis.
What type of parasite test is necessary?
Many patients mistakenly believe that a single test for parasites (stool or smear of the perianal area), showing a negative result, is a guarantee of the absence of parasites in the body. However, in reality everything is not like that and this result means nothing. First, parasites can be extraintestinal, living in other organs and tissues, and therefore their eggs or larvae simply do not end up in the feces.
Secondly, when testing for parasites, there may be a period in the parasite's life where it is still or no longer laying eggs. Thirdly, there is a risk that not all conditions for analysis are met and therefore the eggs are simply not found in the sample provided.
Therefore, if we talk about intestinal worms, when a test for parasites is prescribed, feces are taken three times at a certain interval 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 of parasites taken from a vein, with the determination of antibodies against certain worms. If the body has been in contact with the parasite very recently, class M antibodies will be present which will identify the pathogen. Long-term presence of the parasite will also produce antibodies of other classes.