Special diseases classified as contagious include parasitosis. They are caused by special parasites that have adapted to live in or on the human body, feeding and multiplying in or with it. In this case, the person can be the intermediate and final host of the 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, a number of diseases caused by them can be identified. The most common is helminthiasis - diseases resulting from the parasitism of special types of worms.
Parasites: different types of helminths in the body
The largest group of parasites in the human body are different types of flat and round worms. They belong to a separate group of diseases, which doctors collectively call "helminthiasis". Each parasite of this group has its own route and method of infection, characteristics of the life cycle and the development of clinical manifestations, as well as methods of treatment. In addition, each parasite can cause special complications due to its life cycle. The most common parasites that can make people sick are pinworms, roundworms, trichinella, pig or cattle 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 human body. However, in order for the treatment to be effective and correct, it is important to know the specific types of parasites and which organs and systems they affect. For this, it is important that they carry out a full examination and pass a number of tests. Why is this necessary?
First of all, it is important to remember that the different types of parasites live in the host organism in the larval stage (if a person is their intermediate host) or as a sexually mature individual (if the final host). In this regard, the therapeutic effects may differ depending on the stage of the parasite and the habitat of the parasite.
Types of parasites such as echinococci can be dangerous to humans in the larval stage. The larvae infect the lungs, liver, kidneys or brain in the form of a round cyst capsule filled with a poisonous liquid. In these organs, an echinococcus cyst with larvae inside grows for months or years. But these types of parasites, such as pinworms, live in the body in the form of sexually mature individuals. Females crawl out of the anus to lay millions of eggs, which are passed into the external environment in faeces.
Depending on the type of parasites and the body's individual reactions to them, the location of the lesion and the body's reaction, the clinical manifestations range from asymptomatic to pronounced and severe, even fatal outcomes. It is also good to remember that there are variants of mixed infections when several 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 through contaminated food or water, from dirty hands, or through damaged skin or insect bites. It often happens that worm eggs remain in the form of eggs in the soil, water or on the surface of objects for a long time. Entering the body through improperly treated hands, food or water, the parasites enter the body, where the eggs quickly mature and hatch into larvae (intermediate versions of the parasite) or adults.
It is important to remember that parasites in the body can 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 allergenic effect of the body, over-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, especially when 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, which are often filled with worm waste. The body often reacts to the introduction of parasites with indigestion, 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 affects only people from the poorest countries and those who are careless about hygiene. The prevalence of worms is amazing, according to the WHO, it is comparable to diseases such as ARVI and influenza. Therefore, regular examination and the exclusion of parasitosis are necessary.
What parasite test is needed?
Many patients mistakenly believe that a single test (feces or smear from the perianal area) showing a negative result guarantees the absence of parasites in the body. However, in reality, everything is not like that, and this result means nothing. First, the parasites can be extraintestinal, living in other organs and tissues, and then their eggs or larvae simply do not pass into the feces.
Second, when performing parasite tests, there may be a period in the parasite's life when it still or no longer lays eggs. And thirdly, there is a risk that all the conditions necessary for the analysis are not met, and therefore the egg is simply not found in the given sample.
Therefore, if we are talking about intestinal worms, when an examination of parasites is prescribed, feces are taken three times at certain intervals to confirm the presence or absence of parasites. Only this technique can confirm or deny the diagnosis with up to 90% probability.
In this regard, it is better to analyze the parasites taken from the vein with the determination of antibodies against certain worms. If the body has had recent contact with the parasite, it will have class M antibodies against it, which identify the pathogen. The long-term presence of the parasite also produces antibodies belonging to other classes.