Parasitic infections: causes, symptoms.

Parasitic infections represent a diverse range of symptoms and diseases 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 maintaining 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, as in the case of the mites that cause demodicosis, their 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 habitats.Some ectoparasites carry serious diseases: typhus, anthrax, encephalitis and trypanosomiasis.They cause enormous harm to human health, including death.
2. Endoparasites (protozoa).
   It mainly affects internal organs.They have a unicellular structure, hence the name protozoa.Despite this, they can lead to serious forms of the disease.The main diseases in this group are blood parasitic infections caused by toxoplasma and intestinal infections caused by amoeba or giardia.
3. Helminths.
   They are the causative agents of the most common forms of parasitic infections.In the human body, its development cycles occur mainly in the intestines and tissues, where the symptoms of the disease begin to manifest.

Roundworms (nematodes)

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

1. Pinworm.The disease is caused by enterobiasis.It mainly affects children of preschool and primary school age.
2. Whipworm.It causes the disease trichuriasis.It has a distinct body shape.2/3 of the length of the body 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).After 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 are unable to re-enter the bloodstream through the pores due to their large size.There they grow and become adults within 2 to 3 months.After that, reproduction begins and the cycle repeats.The female can lay more than 200,000 eggs per day.

Tapeworms (cestodes)

They 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 (2-9 mm) and consists of several segments and suckers.The uterus of a sexually mature individual contains a large number of eggs, inside which there are larvae.The main localization sites for the echinococcus are the liver and lungs.There it causes a chronic disease called hydatid cyst.
2. Bull tapeworm.It causes the disease teniarinchiasis.In the larval stage, it has an intermediate host - cattle.Once in the human body, it develops in the small intestine to the ribbon stage.The body of an adult parasite has up to 1,000 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 an intermediate host.In the human body, it parasitizes the small intestine.An adult can reach several meters in length.

Flatworms (worms)

During their life cycle, these parasites can alter 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.Furthermore, with blood flow, the eggs spread throughout the body and continue their development in any organ.Body length 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 fruits and vegetables.Meat that has not undergone sufficient heat treatment is especially dangerous.Also, a person becomes infected with a parasitic infection if personal hygiene rules 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 path.The parasite is transmitted through dirty hands, contaminated personal belongings and underwear.This is how lice, scabies and pinworms are most often transmitted.
5. Transmission path.Infection occurs after the bite of parasite-carrying insects.For example, malaria.

Symptoms

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

1. Itch.
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 long period.
11. Prolonged attacks of dry cough.
12. Enlarged lymph nodes.
13. Painful sensations in the muscles.
14. Psychoemotional disorders.

Diagnosis

If you suspect the presence of parasitic diseases, you will need to undergo a series of tests.Diagnosis of parasitic infections allows you 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 that live 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 takes smears and examines them under a microscope.This method is often used, but it is not accurate enough.To make the final diagnosis, the patient must perform this exam up to three times at short intervals.This is due to the life cycle of the parasites and the laying of eggs, which are detected by this research method.
   2. Shave (wash) 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 carried out mainly for children.The laboratory technician moistens a cotton swab or glass swab in water or glycerin and rinses it from the perianal folds.Then, the resulting material is applied to a glass slide and examined under a microscope.This analysis is also done using a different method: a laboratory assistant sticks a piece of tape on the anal passage, presses it and removes it.The adhesive tape is then stuck to a glass slide and also viewed under a microscope.The parasite is diagnosed quite accurately.Using these methods, the laboratory assistant is able to 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 patient survey 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 analysis for parasitic infections make it possible to determine the presence and type of pathogen with high accuracy.Three types of such diagnostics are used:
   1. Serological reactions.It allows determining the presence of parasitic antibodies in the patient's blood serum.This method is considered highly specific, but inferior to PCR diagnosis.
   2. Diagnosis by PCR.This method is based on identifying the DNA of parasites in any biological fluid 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 analysis, the doctor excises a small section of an organ, tissue or an entire lymph node and sends it for histological examination.This way the presence or absence of parasites is diagnosed.

Recommendations for preparing for tests

Before taking tests to detect parasitic infections, you need to properly prepare for them.If the recommendations are followed, the diagnostic accuracy increases, since the material does not contain interfering factors that affect the effectiveness of research methods.

Preparing for a stool test:

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

Preparing for a blood test:

1. It is necessary to stop taking pharmacological medications that affect the blood count.
2. Three days before the test, you should follow a light diet, 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 drinking water.

For other tests, most of the time no special preparation is needed.You will only need to follow the doctor's recommendations.

Treatment

Unfortunately, symptoms of parasitic infections cannot always be detected in the early stages of the disease.In these cases, treatment starts 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.

Therapy of infectious and parasitic infections is divided into two areas:

1. Symptomatic treatment.It aims to eliminate the clinical manifestations of the disease.This includes 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 fluke 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 patient interviews.

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 bathroom and returning home from the street.
2. Vegetables and fruits must 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 is not always 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, they need to be dewormed 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. You should iron underwear (especially children's) after washing.
7. After visiting exotic countries, when working with land, as well as employees of children's institutions, it is recommended to undergo examinations once a year to detect the presence of parasites and, if necessary, carry out prophylaxis with medications.