Specific diseases classified as infectious include parasitosis. They are caused by special parasites that have adapted to life inside or on the human body, feeding and reproducing there or with its help. In this case, a person can be both an intermediate host and a 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 helminthiasis, diseases resulting from the parasitism of particular 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 separate group of diseases, which doctors collectively call "helminthiasis". Each parasite of this group has its own routes and methods of infection, features of the life cycle and development of clinical manifestations, as well as methods of 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 from are pinworms and roundworms, trichinella, pork or cattle tapeworm.
Types of parasites and features 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 the organs and systems that are affected by them. To do this, it is important to undergo a comprehensive 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 the larval state (if a person is its intermediate host) or sexually mature individual (if it isof the final host). In this regard, the therapeutic effects, depending on the stage of parasitization of the worm, may be different, as well as the habitat of the parasite.
Types of parasites such as echinococcus will be dangerous for humans in the larval stage. The larvae, in the form of a round cystic capsule filled with toxic fluid, infect the lungs, liver, kidneys or brain. Inside these organs, for several months or years, an echinococcal cyst develops, inside which there are larvae. But such types of parasites 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 along with feces.
Depending on the type of parasites, as well as the individual reactions of the body to them, the localization of the lesion and the body's response, clinical manifestations range from asymptomatic to pronounced and severe, even fatal. It is also worth remembering that there are variants of mixed infections, when several types of parasites live in the body simultaneously.
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, through dirty hands, as well as through damaged skin or insect bites. Worm eggs often remain as eggs in soil, water or on the surface of objects for a long time. Entering the body through hands, food or not properly treated water, the parasites enter the body, where the eggs quickly 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 harm, even if there are no obvious signs of damage. First, they eat their host, depriving it of certain nutrients, vitamins and minerals. In addition, parasites present in the body sharply increase the allergenicity of the body, excessively stimulate the immune system, which threatens the development of spontaneous skin reactions and other allergic reactions to previously quite familiar products and substances.
The body does not remain indifferent to the penetration of worms, especially if it concerns soft tissues and internal organs. Thus, protective inflammatory capsules form in muscles and tissues, separating the parasite from 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 they are worms living in the intestines, changes in appetite, weight fluctuations and exacerbation of chronic diseases.
Don't think that the problem of parasites only concerns people in poorer countries and those who don't care about hygiene. The prevalence of helminths is astonishing: according to the WHO, it is comparable to diseases such as ARVI and influenza. It is therefore necessary to undergo regular examinations and to exclude any parasitosis.
What type of parasite test is needed?
Many patients mistakenly believe that a single test for parasites (feces or smear from the perianal area), which gives a negative result, is a guarantee of the absence of parasites in the body. However, in reality, everything is not like this and this result means nothing. First, parasites can be extraintestinal, living in other organs and tissues, and their eggs or larvae simply don't end up in the stool.
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 analysis conditions will be met and eggs will simply not be found in the sample provided.
Therefore, if we talk about intestinal worms, when a parasite test is prescribed, stools are taken three times at a certain interval to confirm the presence or absence of parasites. Only this technique can confirm or refute the diagnosis with a probability of up to 90%.
More revealing in this regard is an analysis of parasites taken from a vein, with determination of antibodies directed against certain worms. If the body has been in contact with the parasite very recently, there will be class M antibodies against it, which will help identify the pathogen. The long-term presence of the parasite will also produce antibodies of other classes.