Specific diseases classified as infectious include parasitic infections. 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 of 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 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 that 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 treatment. Furthermore, each parasite is capable, due to its life cycles, of causing specific complications. The most common parasites that can make people sick are pinworms and intestinal worms, trichinella, porcine or bovine 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 which organs and systems are affected by them. To do this, it is important to undergo a comprehensive examination and pass a series of tests. Why is this 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 a person is its intermediate host) or as a sexually mature individual (if it is the final host). In this sense, the therapeutic effects, depending on the stage of the parasitizing worm, may 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 fluid, infect the lungs, liver, kidneys or brain. Within these organs, for many months or years, an echinococcal cyst grows, inside which the larvae are found. But such types of parasites as pinworms live in the body in the form of sexually mature individuals. Females emerge from the rectum to lay millions of eggs, which are released outside with feces.
Depending on the type of parasite, as well as the individual reactions of the body to them, the location of the lesion and the body's response, clinical manifestations vary 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 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 parasite eggs enter the human body with contaminated food or water, through dirty hands, as well as through damaged skin or from 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 have not been properly treated, parasites penetrate 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 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 sharply increase the allergenicity of the body, overstimulate 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 into it, especially if it concerns soft tissues and internal organs. Thus, protective inflammatory capsules form in muscles and tissues, which separate the parasite from healthy tissues. This leads to the formation of parasitic cysts, often filled with the worms' waste products. Often, the body also reacts to the introduction of parasites with digestive disorders, whether it is worms living in the intestines, changes in appetite, weight fluctuations and exacerbation of chronic diseases.
Do not think that the problem of parasites only affects people in the poorest countries and those who do not care about hygiene. The prevalence of helminths is striking, according to the WHO, it is comparable to diseases such as ARVI and influenza. Therefore, it is necessary to undergo periodic examinations and rule out parasites.
What type of parasite test is needed?
Many patients mistakenly believe that a single parasite test (stool or a 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 that and this result means nothing. First, parasites can be extraintestinal and 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 laying eggs or no longer laying eggs. And thirdly, there is a risk that not all conditions for analysis are met and, therefore, the eggs simply will not be found in the provided sample.
Therefore, if we talk about intestinal worms, when a parasite test 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 refute the diagnosis with a probability of up to 90%.
More indicative in this regard is a parasite analysis taken from a vein, with determination of antibodies against certain worms. If the body has been in contact with the parasite very recently, there will be class M antibodies that will identify the pathogen. The prolonged presence of the parasite will also produce antibodies of other kinds.