Parasitic infections: causes, symptoms.

Parasitic infections represent a wide range of symptoms and diseases that are caused by the entry of eggs or adult parasites into the human body.Often the first signs of the disease cannot be detected for several days, and in some cases several months or even years.This is due to the life cycle of parasites and their main functions: good camouflage and maintenance of their own life by receiving nutrients from the host's body.

Types of parasites and their characteristics.

Parasitic infections, depending on certain properties of their manifestation, are divided into three groups:

1. Ectoparasites.
   The main location is the surface of the human body.These include lice, fleas, ticks and bed bugs.They feed predominantly on human blood, although in some cases, such as the mites that cause demodicosis, the main food is the secretion of sebaceous glands or dead epithelial (skin) cells.The first signs of a parasitic infection are quite easy to recognize, as they cause itching and burning in their habitat.Some ectoparasites carry serious diseases: typhus, anthrax, encephalitis and trypanosomiasis.They cause enormous damage to human health, including death.
2. Endoparasites (protozoa).
   It mainly affects internal organs.They have a single-celled structure, hence the name protozoa.Despite this, they can cause serious illnesses.The main diseases of this group are parasitic blood infections caused by toxoplasma and intestinal infections caused by amoebas or giardia.
3. Helminths.
   They are the causative agents of the most common forms of parasitic infections.In the human body, its development cycles take place mainly in the intestines and tissues, where the manifestation of the symptoms of the disease begins.

Intestinal worms (nematodes)

These are parasites whose body has a round cross section.Sexual characteristics are easily distinguishable.Females are usually larger than males.But representatives of this class are also hermaphrodites.All nematodes go through stages of development: egg, larva and adult.This class includes:

1. Intestinal worm.The disease is caused by enterobiasis.It mainly affects children of preschool and primary school age.
2. Worm.It causes the disease trichuriasis.It has a distinctive body shape.2/3 of the body length has a thin diameter, reminiscent of human hair or thread.The other end of the body has a larger diameter and contains the intestines.
3. Ascaris.The disease is caused by ascariasis.Adults reach sizes of 25 cm (males) and 40 cm (females).Once the larva enters the human body, it passes through the stomach and enters the small intestine.From there, through the pores with blood flow, it enters the liver, then the heart, and then the lungs, where it develops within 7-10 days.Then the larvae begin to climb into the larynx.Once they reach the oral cavity they are swallowed again.Once in the small intestine, the larvae cannot re-enter the bloodstream through the pores due to their large size.There they become adults in 2-3 months.After this, playback begins and the cycle repeats.The female can lay more than 200 thousand eggs a day.

Tapeworms (cestodes)

These are parasites whose body resembles the shape of a ribbon.A distinctive feature of this class is the absence of a digestive system.These include:

1. Echinococcus.The disease is caused by echinococcosis.This parasite is small in size (2-9 mm) and consists of several segments and suction cups.The uterus of a sexually mature individual contains a large number of eggs, inside of which the larvae are located.The main locations of echinococcus are the liver and lungs.There it causes a chronic disease called hydatid cyst.
2. Had of the bull.It causes the disease teniarhinchiasis.In the larval stage, it has an intermediate host: livestock.Once in the human body, it develops in the small intestine to the ribbon stage.The body of an adult parasite has up to 1000 segments and can reach 4 to 10 meters in length.
3. Pork tapeworm.It causes the disease taeniasis.Externally, it is very similar to a bull tapeworm.It also has intermediate hosts: pigs, dogs, camels, hares and rabbits.In humans it is a parasite in the intestines.The size of an adult individual does not exceed 4 meters in length.
4. The tapeworm is wide.The disease is caused by diphyllobothriasis.Lives in freshwater bodies of water.It uses crustaceans and fish as intermediate hosts.In the human body it parasitizes the small intestine.An adult can reach several meters in length.

Flatworms (trematodes)

During their life cycle, these parasites can change several intermediate hosts.In humans they can be parasitized in any organ.This group includes:

1. Schistosomes.The disease is caused by schistosomiasis.They can enter the human body through contact with contaminated fresh water.The parasite penetrates the skin and enters the circulatory system, where it begins to actively multiply.Females can produce 300 to 3,000 eggs per day.In addition, with blood flow, the eggs spread throughout the body and continue their development in any organ.The length of its body does not exceed 0.1-0.2 cm.
2. Liver flukes.The disease is caused by opisthorchiasis.The length of an adult varies from 3 to 5 cm.When it enters the human body, it parasitizes the bile ducts, gallbladder, liver and pancreas.It is fixed to these organs using suction cups located on the body.

Ways of penetration of parasites into the human body.

1. The nutritional route of infection is considered the most common.A person becomes infected with the parasite by eating poorly washed vegetables and fruits.Meat that has not undergone sufficient heat treatment is especially dangerous.Also, a person becomes infected with a parasitic infection if the rules of personal hygiene are not followed.For example, not washing your hands before eating.
2. Transplacental route.The parasitic infection is transmitted from the pregnant woman through the placenta to the child.For example, these are diseases such as toxoplasmosis, malaria or hookworm.
3. Percutaneous route.The parasite enters the human body through the skin.These are mainly schistosomes and hookworms.
4. Contact route.The parasite is transmitted through dirty hands, contaminated personal items and underwear.This is how lice, scabies and pinworms are most often transmitted.
5. Transmission route.The infection occurs after the bite of insects that carry parasites.For example, malaria.

Symptoms

Many parasitic diseases have no symptoms in the early stages.This is due to the stages of development of the pathogen.Each individual type of parasite manifests itself differently as it grows.Common general symptoms of parasitic infection include:

1. Itching.
2. Redness of the skin like hives.
3. Diarrhea.
4. Constipation.
5. Flatulence.
6. Nausea, vomiting.
7. Spasms and pain in the gastrointestinal tract.
8. Lose body weight without dieting or increasing physical activity.
9. Feverish condition.
10. Elevated body temperature (38-40˚C) for a prolonged period.
11. Prolonged attacks of dry cough.
12. Enlarged lymph nodes.
13. Painful sensations in the muscles.
14. Psychoemotional disorders.

Diagnosis

If the presence of parasitic diseases is suspected, it is necessary to undergo a series of tests.The diagnosis of parasitic infections allows us to determine the presence or absence of a parasite, its type and location in the body.The data obtained will help the doctor make the correct diagnosis and prescribe the correct treatment.

Diagnostic methods include:

1. Stool examination.It allows you to determine the presence of most types of parasites living in the intestines.Their eggs, larvae and body segments are excreted in feces.There are two types of analysis:
   1. A stool sample is examined for helminth eggs and larvae.The analysis is delivered to the laboratory, where the doctor makes swabs and examines them under a microscope.This method is frequently used, but it is not accurate enough.In order to make a definitive diagnosis, the patient must undergo this test up to three times with short time intervals.This is due to the life cycle of the parasites and the laying of eggs, which are detected by this research method.
   2. Scraping (washing) of the folds of the anus.This test is used to detect only one type of helminth: pinworms.Parasitic infections are more common in children than in adults.For this reason, this analysis is done primarily for children.The laboratory technician moistens a cotton or glass swab in water or glycerin and rinses it from the perianal folds.The resulting material is then applied to a glass slide and examined under a microscope.This analysis is also performed using a different method: a lab assistant sticks a piece of tape to the anal canal, presses it, and removes it.The adhesive tape is then attached to a glass slide and also observed under a microscope.The parasite is diagnosed quite accurately.With these methods, the laboratory assistant can examine not only helminth eggs, but sometimes also adult individuals.
2. Examination of cerebrospinal fluid, sputum, duodenal contents (bile), urine.Prescribed based on the results of a survey of patients to determine the presence of the parasite and determine its location.These biological fluids are analyzed by microscopy and macroscopy.First, the resulting sample is examined for the presence of adult individuals, and then microscopy is performed to detect parasite eggs and larvae.
3. Blood test.Modern methods of blood testing for parasitic infections make it possible to determine the presence and type of pathogen with great accuracy.Three types of such diagnostics are used:
   1. Serological reactions.Allows you to determine the presence of parasite antibodies in the patient's blood serum.This method is considered very specific, but inferior to PCR diagnosis.
   2. Diagnosis by PCR.This method is based on identifying the DNA of the parasites in any biological fluid that has been taken for analysis.
   3. Genetic research.It involves detecting the parasite's genome in a patient's blood sample.This method is used much less frequently than all the others, but it has high accuracy.
4. Examination of biopsy material and lymph nodes.For this test, the doctor removes a small section of an organ, tissue, or an entire lymph node and sends it for histological examination.In this way, the presence or absence of parasites is diagnosed.

Recommendations to prepare for the tests.

Before testing for parasitic infections, you must properly prepare for them.If the recommendations are followed, the accuracy of the diagnosis increases, since the material does not contain factors that interfere and affect the effectiveness of the research methods.

Preparing for a stool test:

1. Antibiotics, anti-inflammatories and antacids should be discontinued.The use of medications and other drugs containing bismuth and iron is also unacceptable.
2. If a barium X-ray examination or a colonoscopy was performed, during which an enema was performed to cleanse the intestines, then a stool test can be done only after 2-3 days.
3. It is not recommended to donate stool if menstrual bleeding begins or hemorrhoids worsen.

Preparing for a blood test:

1. It is necessary to stop taking pharmacological medications that affect blood count.
2. Three days before the test, you should follow a light diet, do not eat fatty foods and give up alcohol.
3. A blood test for parasitic infections is done on an empty stomach.It is allowed to drink a small amount of clean drinking water.

For other tests, most of the time no special preparation is required.It will only be necessary to follow the doctor's recommendations.

Treatment

Unfortunately, the symptoms of parasitic infections cannot always be detected in the initial stages of the disease.In such cases, treatment begins late.It is important to understand: the longer the parasite remains in the body, the more difficult it will be to get rid of it.

The therapy of infectious and parasitic infections is divided into two areas:

1. symptomatic treatment.Aimed at eliminating the clinical manifestations of the disease.These include reducing body temperature, eliminating redness and itching, and normalizing the functioning of the gastrointestinal tract.
2. The etiological treatment of parasitic infections aims to eliminate the causative agent of the disease.

In some cases, surgery may be necessary.It is applicable for alveococcosis, echinococcosis and some types of trematode infection.

When the body is dehydrated, solutions containing salt are prescribed.

Only a doctor can prescribe treatment for parasitic infections based on laboratory tests and interviews with patients.

Prevention

It is very important to observe the prevention of parasitic infections.In most cases, this will help prevent pathogens from entering the body.

Preventive measures include:

1. Compliance with personal hygiene rules: it is necessary to wash your hands before eating, after going to the toilet and when returning home from the street.
2. Vegetables and fruits should be washed well.
3. It is imperative to carry out sufficient heat treatment of meat, fish and seafood.
4. Tap water should not be used as drinking water as it may not always be free of parasites.Using household filters as additional cleaning will not help.The best option would be to drink boiled or bottled water.
5. If pets live at home, it is necessary to deworm them once every six months.You should also limit contact with your pet if it shows signs of parasitic diseases and contact a veterinary clinic.
6. It is advisable to iron underwear (especially children's) after washing.
7. After visiting exotic countries, when working with the land, as well as employees of children's institutions, it is recommended to be examined once a year for the presence of parasitic infections and, if necessary, carry out prophylaxis with medications.