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 final host for parasites (that is, either eggs and larvae or adults 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 helminthiasis - diseases resulting from the parasitism of certain types of worms.
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, flat and round. They belong to a special group of diseases, which doctors collectively call "helminthiases". Each parasite of this group has its own routes and methods of infection, features of the life cycle and the development of clinical manifestations, as well as methods of its treatment. In addition, each parasite is capable, due to its life cycles, of causing specific complications. The most common parasites that people can get sick with are hookworms and roundworms, trichinella, pork or bovine tapeworm.
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, as well as which organs and systems are affected by them. To do this, it is important to undergo a complete examination and pass a number of 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 a person is the intermediate host) or a sexually mature individual (if it is the final host). In this regard, the therapeutic effects, depending on the stage of worm parasitism, can be different, as well as the habitat of the parasite.
Parasite species such as echinococci will be dangerous to humans in the larval stage. The larvae, in the form of a round cyst capsule filled with a toxic liquid, infect the lungs, liver, kidneys or brain. Within these organs, for many months or years, an echinococcal cyst grows, inside which there are larvae. But such types of parasites as roundworms 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 in feces.
Depending on the type of parasites, as well as the body's individual reactions to them, the location of the lesion and the body's reaction, clinical manifestations vary from asymptomatic to pronounced and severe, and even fatal. It is also worth remembering that there are variants of mixed infections, when several types of parasites live simultaneously in the body.
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 from 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 surfaces of objects. Entering the body through hands, food or water that has not been properly treated, the parasites penetrate the body, where the eggs quickly mature into larvae (intermediate versions of the parasite) or mature individuals.
It is important to remember that parasites in the body cause serious damage, even if there are no visible signs of damage. First of all, they eat their host, depriving it of certain nutrients, vitamins and minerals. In addition, parasites in the body significantly increase the allergenicity of the body, over-stimulate the immune system, which threatens the development of spontaneous skin and other allergic reactions to previously known products and substances.
The body is not indifferent to the penetration of worms into it, especially if it comes to soft tissues and internal organs. Thus, protective inflammatory capsules are formed in muscles and tissues, separating the parasite from healthy tissues. This leads to the formation of parasitic cysts, often filled with worm waste products. Often the body also reacts to the introduction of parasites with digestive disorders, if it comes to worms living in the intestines, changes in appetite, weight fluctuations and worsening of chronic diseases.
Do not think that the problem of parasites is only important for people from poorer 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 exclude parasitosis.
What type of parasite test is needed?
Many patients mistakenly believe that a single test for parasites (feces or a 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 like that, and this result means nothing. First, parasites can be extraintestinal, live in other organs and tissues, and then their eggs or larvae simply do not end up in the feces.
Second, at the time of parasite testing, there may be a period in the parasite's life when it is still or no longer laying eggs. And thirdly, there is a risk that not all the conditions for analysis are met and therefore the eggs are simply not found in the sample that was given.
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 reject the diagnosis with a probability of up to 90%.
The most indicative in this regard is an analysis for parasites taken from a vein, with the determination of antibodies against some worms. If the body has been in contact with the parasite very recently, there will be class M antibodies against it, which will identify the pathogen. Long-term presence of the parasite will also produce antibodies of other classes.