Specific diseases classified as contagious include parasitosis. They are caused by special parasites that have adapted to live inside or on the human body, feeding and multiplying in it or with its help. In this case, a person can be both an intermediate and a final host for parasites (that is, 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 are helminth infections - diseases that arise as a result of 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 special 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 its treatment. In addition, each parasite is capable, due to its life cycle, of causing certain complications. The most common parasites that can make people sick are pinworms and roundworms, trichinella, pork or beef 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 a person's body. However, in order 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 series 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 the person is their intermediate host) or in the sexually mature individual (if the final host). In this regard, the therapeutic effects, depending on the stage in which the parasite is parasitized, can be different, as well as the habitat of the parasite.
Parasite species such as Echinococcus will be dangerous to humans in the larval stage. The larvae, in the form of a round cyst capsule filled with a poisonous liquid, infect the lungs, liver, kidneys or brain. Within these organs, for many months or years, an echinococcal cyst grows, inside of 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 that are released into the environment with their feces.
Depending on the type of parasite, as well as the body's individual reactions to them, the location 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 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 parasite eggs enter the human body with contaminated food or water, from dirty hands, as well as through damaged skin, by 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 has not undergone proper treatment, the parasites penetrate the body, where the eggs quickly mature, and the 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 of all, they eat their host, depriving it of some nutrients, vitamins and minerals. In addition, parasites in the body sharply increase the allergenicity of the organism, excessively stimulate the immune system, which threatens the development of spontaneous skin 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 are formed in muscles and tissues that separate the parasite from healthy tissues. This leads to the formation of parasitic cysts, often filled with worm waste products. Often, the body reacts to the introduction of parasites with digestive disorders, if they are worms that live in the intestines, changes in appetite, weight fluctuations and worsening of chronic diseases.
Do not think that the problem of parasites is relevant only for people from the poorest countries and those who do not care about hygiene. The prevalence of helminths is incredible; according to the WHO, it is comparable to diseases such as ARVI and influenza. That is why it is necessary to undergo regular examinations and rule out parasitosis.
What type of parasite test is needed?
Many patients mistakenly believe that a single parasite test (feces or swab 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, living in other organs and tissues, and then their eggs or larvae simply do not end up in the feces.
Second, at the time the parasite tests are taken, there may be a period of 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 the analysis are met, so the eggs are simply not found in the sample provided.
So, if we are talking 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 the analysis of parasites taken from a vein, along with the determination of antibodies against certain worms. If the body has recently been in contact with a parasite, there will be class M antibodies to it, which will identify the pathogen. Prolonged presence of parasites will also produce antibodies of other classes.