Worms and parasites: types of diseases, symptoms, routes of infection, treatment

Parasitic intestinal diseases include

• helminthiases caused by parasitic worms (helminths),
• protozoa caused by protozoa (amoeba, lamblia).

Diseases caused by protozoa

Currently, thanks to electron microscopes, a wide variety of protozoa can be observed. Their clear classification is difficult due to the lack of clear similar features.

Particular attention is paid to the study of species harmful to humans. These protozoa belong to 5 types:

• Rhizopoda (rhizopoda) - amoeba,
• Kinetoplastida (kinetoplastids) - Leishmania and trypanosomes,
• Polimastigota (polymastigota) - Giardia and Trichomonas
• Sporozoa (sporozoa) - plasmodia of malaria, toxoplasma, etc.,
• Ciliophora (ciliophora) - balantidia.

Infection of the body with these protozoa leads to diseases such as

• malaria,
• toxoplasmosis,
• leishmaniasis,
• trypanosomiasis,
• pneumocystosis,
• babesiosis,
• amoebiasis,
• acanthamoebiasis,
• balantidiasis,
• trichomoniasis,
• giardiasis.

The most widespread of the above in Russia is giardiasis. Poor water quality contributes to the increase in the number of cases. Giardia cysts are often found in open water bodies in the area of ​​water intakes. It is often isolated when testing tap water.

Treatment of water with chlorine in standard concentrations does not have a detrimental effect on Giardia cysts, amoebas and some others.

Tourism and migration of a large number of people have led to the emergence of tropical and previously eradicated parasitoses on Russian territory. First of all, these include malaria, amoebiasis, leishmaniasis, strongyloidiasis, schistosomiasis, hookworm disease, etc.

What are helminths?

Helminths (worms) are multicellular animal organisms that parasitize humans, animals and plants.

There are 4 classes of helminths:

• flatworms,
• roundworms (nematodes),
• spiny-headed worms (acanthocephals),
• annelids.

Round and flatworms parasitize humans. Spiny-headed and annelid worms are extremely rare in humans.

Flatworms are divided into two distinct groups:

• tapeworms (cestodes),
• flukes (trematodes).

The organism in which the worms settle is called the host.

What is helminthiasis?

Helminth infections are diseases of humans, animals and plants caused by parasitic worms, helminths (worms).

The following groups of helminthiases are distinguished:

• trematodes caused by trematodes (flukes);
• cestodes, causative agent - cestodes (tapeworms);
• nematodes, causative agent - nematodes (roundworms);
• acanthocephalosis, causative agent - acanthocephala (spiny-headed worms, acanthocephalans).

The names of helminth infections are formed by adding the suffixes “oz” or “dose” to the name of the pathogen (worm). For example, askari doses.

The most common diseases in humans are:

• from trematodes - opisthorchiasis (feline or Siberian fluke), fascioliasis ( liver fluke ), paragonimiasis ( pulmonary fluke ), dicroceliosis ( lanceolate fluke );
• from cestodiasis - teniarinhoz (bovine tapeworm), diphyllobothriasis (wide tapeworm), taeniasis (pork tapeworm), hymenolipidosis ( dwarf tapeworm ), echinococcosis (unilocular echinococcus and multilocular alveococcus);
• from nematodes - ascariasis (human roundworm), enterobiasis (pinworm), hookworm (hookworm), necatoriasis ( nekator ), trichinosis (trichinella), trichuriasis (whipworm), strongyloidiasis ( intestinal eel ), toxocariasis (Toxocara larva).

Helminthiases caused by spiny-headed worms (acanthocephalans) are usually not found in humans.

Different types of helminths live in different organs and tissues. First of all, the organ in which they parasitize is affected. Although it has a negative impact on the entire body as a whole.

Over 250 species of helminths that parasitize humans are known and well studied. 98 of them are common in Russia, the most common are 14 species.

Helminths common in Russia are given in the following table:

Type	Class	View	Disease
Roundworms	Nematodes	Ascaris lumbricoides Enterobius vermicularis Trichocephalus trichiurus Taxocara canis Trichinella spiralis Strongyloides stercoralis Ancylostoma duodenale Necator americanus	Ascariasis Enterobiasis Trichocephalosis Toxocariasis Trichinosis Strongyloidiasis Hookworm Necatoriasis
Flatworms	Cestodes (tapeworms)	Diphyllobothrium latum Hymenolepis nana Taenia saginata Taenia solium Echinococcus granulosus Alveococcus multilocuralis	Diphyllobothriasis Hymenolepiasis Taeniarinchiasis Teniosis Echinococcosis Alveococcosis
Flatworms	Trematodes (flukes)	Opisthorchis felineus Fasciola hepatica Paragonimus westermanii	Opisthorchiasis Fascioliasis Paragonimiasis

Symptoms of the disease can vary and depend on many reasons:

• from the type of helminths,
• their localization,
• quantities,
• the method of fixing them in the body (for example, to the intestinal mucosa),
• from the general condition of the organism in which they appear, etc.

Most worms parasitize the human small intestine (roundworms, hookworms , strongyloides, tapeworms, tapeworms).

in the colon , and schistisoma eggs are found in the wall of the colon. Here they injure the mucous membrane, which leads to disruption of the motor and secretory functions of the intestine, and the digestion process is disrupted.

Pork tapeworm larvae (cysticerci) penetrate from the intestine into the blood and spread to the muscles, fiber, brain, etc.

Symptoms of helminthiases

Almost always helminthiases are accompanied

• weight loss, even in the mildest cases,
• and smaller or larger manifestations of the nervous system - general malaise, dizziness, irritability, etc.

When parasitizing helminths in the intestines,

• constipation,
• diarrhea,
• nausea,
• stomach ache,
• less often vomiting.

When worms are localized in the liver, they appear

• jaundice,
• swelling.

When these parasites develop in the lungs -

• cough,
• discharge from the nose.

With all helminthiases, a decrease in working capacity is observed, and in children, physical and intellectual development is impaired, growth retardation, sexual development, memory impairment, etc.

Infection with helminths at the acute (early) stage is manifested by the following symptoms:

• allergic reactions (eczema, bronchospasms),
• fever,
• various rashes,
• skin itching,
• volatile infiltration of the lungs,
• hypereosinophilia (increased number of eosinophils in various body fluids and blood).

In case of chronic helminthiasis,

• pain and discomfort in the abdomen of varying severity,
• stool disorders,
• decreased ability to work,
• headache,
• sleep disorders
• symptoms of asthenia (chronic fatigue, lack of appetite, increased fatigue),
• irritability,
• depression (“going into illness”),
• sleep disturbance.

Pinworm infestation is accompanied by

• perianal itching,
• sometimes pain in the right iliac region.

When infested with hookworms, iron deficiency anemia develops.

Why are worms harmful?

To ensure their vital functions, helminths absorb nutrients from the food mass in the intestines - the most valuable proteins, vitamins, and microelements. Some helminths (such as whipworms) feed on blood, which leads to anemia.

In addition, by spreading through body tissues, worms damage them (for example, lungs, liver, eyes, brain).

According to the conclusion of the International Agency for Research on Cancer, opisthorchiasis is classified as a first group of carcinogens, that is, opisthorchiasis can cause primary liver cancer.

With helminthiases, changes in the kidneys often occur, caused by general toxic damage to the body or the direct effect of worms on organ tissue.

Many helminthiases last for years. This is due to both the long lifespan of parasites and their ability to suppress the human immune system.

Stages of development of helminthiases

The mechanisms of parasitism of various worms in the human body have much in common.

There are three main phases of the development of the disease:

• acute or early phase - allergic reactions to parasite antigens develop, the duration of the phase is 2-4 weeks,
• latent phase - gradual maturation of the helminth occurs in tissues or organs,
• chronic phase - corresponds to the lifespan of a sexually mature parasite (roundworm, tapeworm, etc.) or its larva (echinococcus, cysticercus, etc.) in the human body.

Routes of infection

According to the methods of infection of humans and animals, all helminthiases are divided into two large groups:

• biohelminthiasis,
• geohelminthiases.

Biohelminth develops completely in the organisms of two or more hosts, reaching the sexually mature stage in the last (definitive) host.

The organism in which the initial stage of the helminth (larva) develops from the egg is called an intermediate host.

An organism in which the subsequent larval stage develops, but the adult helminth cannot develop, is called an additional host.

By eating the meat of an intermediate or additional host, you can become infected with worms. For most biohelminths, humans are the definitive host. And only for some (for example, for echinococcus) it is an intermediate host.

Soil is required for geohelminth eggs to mature in the early stages. Once in the host's body, the larva develops into an adult (roundworm, hookworm).

Infection with helminths can occur in three main ways.

Upon contact with contaminated soil where helminth eggs and larvae develop:

• strongyloides (Strongilloides stercoralis),
• hookworm (Ancylostoma duodenale),
• Necator americanus,
• roundworms,
• toxocara.

When eating products prepared from intermediate hosts of these worms:

• bovine and pork tapeworm,
• wide tape,
• opisthorchis,
• fascioli and others.

In case of personal contact, using common objects, since an infected person releases mature eggs:

• pinworms,
• dwarf tapeworm.

The incidence of intestinal helminths is higher than that of intestinal infections and parasitic diseases combined.

 Diagnostics

To detect worms, various diagnostic methods are used, since the picture of the disease is different for different helminths.

1. Examination of stool and/or duodenal contents for eggs and larvae of helminths, Giardia cysts or amoebas can detect them in the intestines and liver.
2. Sputum examination is necessary to identify helminths in the lungs.
3. In addition, blood tests, fluoroscopy , and ultrasound ( ultrasound ) are used.
4. Immunodiagnosis (determination of the pathogen by identifying its reactions to certain administered drugs) is used in the acute stage of helminthiases, echinococcosis and trichinosis.

 Treatment

Treatment in most cases is medicinal and does not require hospitalization. When taking medications, allergic reactions may occur as a reaction of the body to antigens that are formed as a result of the death of helminths.

Therefore, treatment of a number of helminthiases with systemic lesions of the lungs, liver and heart muscle (intestinal schistomosis, fascioliasis and opisthorchiasis) must be carried out in a hospital.

In these cases, along with the main treatment, detoxification (cleansing) of the body is carried out. Drip intravenous infusions of hemolysis, isotonic solution of glucose and sodium chloride, calcium gluconate and antihistamines are used. In case of severe allergic reactions, glucocorticosteroids are used.

In some cases, surgical treatment is necessary.

Preparations for the treatment of parasitosis

Currently, a large number of drugs have been developed for the treatment of parasitosis.

For the treatment of helminthiasis, broad-spectrum drugs (albendazole, mebendazole and praziquantel) and narrow-spectrum drugs (pyrantel, piperazine, niclosamide) are used.

In addition to these medications, it is recommended to take vitamins and medications to restore intestinal microflora. Fermented milk products with bacterial, but not fungal, fermentation also help restore microflora.

To prevent severe allergic manifestations, antihistamines and glucocorticoids are used.

To restore the digestion process, it is sometimes advisable to take digestive enzymes - pancreatin (Creon, pancitrate), choleretic drugs.

When treating helminth infections, it should be taken into account that modern drugs significantly reduce the ability of helminths to resist the body’s digestive enzymes, so it is not always possible to detect a dead helminth in feces.

 Treatment with folk remedies

The search for drugs to treat parasitosis began many centuries ago. Ibn Sina recommended taking elecampane and celandine with sugar with water to expel pinworms. The Salerian Health Code of the early 16th century recommends mint. In Chinese folk medicine, wormwood was used to treat malaria.

In the practice of Russian healers, there are many recipes for treating various types of helminths and parasitosis, which are given in articles describing specific parasites.

Forecast

Most patients recover after treatment for intestinal helminthiases. The ineffectiveness of repeated courses of treatment is associated with impaired immunity.

Prevention

To avoid infection, it is necessary to know the characteristics of the development of helminths and methods of infection with them.

Personal prevention consists of eating well-cooked, fried and salted meat and fish, as these types of treatments kill worm larvae.

It is recommended to buy meat and fish that have passed the control of veterinary and sanitary services.

To protect against infection with geohelminths, you must thoroughly wash your hands (especially after contact with the soil), vegetables, and fruits.

Use filtered tap or boiled water for drinking.

To prevent hookworm infection, which occurs through the skin, it is necessary to isolate the skin from contact with soil and grass that may be infected.

Prevent fecal pollution of the environment.

All patients must undergo follow-up studies after completing the course of treatment. If there is no effect from the first course, you should undergo repeated deworming.

Intestinal worms can contribute to the development of irritable bowel syndrome. In this regard, after deworming, rehabilitation therapy is recommended - light nutrition, enzyme preparations, etc.

Read more about irritable bowel syndrome in this article .