Don't rush to throw the cat away! Diagnosis of parasitic infections

Blood test for worms

However, only a blood test for worms using the ELISA method (enzyme-linked immunosorbent assay) provides 100% reliability and accuracy.

You can take a blood test for worms in St. Petersburg at a modern multidisciplinary medical center.

Myth No. 1. Pregnant women should not keep cats and dogs, as they can become infected with toxoplasmosis.

In fact: NOT EXACTLY SO

The main “hosts” of Toxoplasma gondii, which is a protozoan, are cats, including domestic and stray ones. Oocysts (a special form of the pathogen) of Toxoplasma, which can cause harm to health, are found in cat feces and on fur. Penetrating into the human body, they affect various organs and tissues (liver, spleen, nervous system, eyes, cardiac myocardium, pulmonary epithelium, skeletal muscles).

Typically, toxoplasmosis occurs in humans without complications. However, for people with weakened immune systems and pregnant women, the disease can become a threat. The infection penetrates the placenta and can cause hydrocephalus in the fetus, severe damage to the nervous system, limbs, intrauterine death, or cause spontaneous abortion.

It is indeed possible to become infected with toxoplasmosis through contact with contaminated cat feces. But in order to become dangerous to humans, Toxoplasma must turn from an oocyst into a larva - a period that takes 4-5 days. This means that daily cleaning of the cat’s litter box, veterinary control of the animal and regular anthelmintic treatment will protect against the parasite. But petting stray animals is still not recommended.

It is important to remember that toxoplasmosis is also transmitted by consuming insufficiently cooked meat containing cysts (lamb, pork). Therefore, pregnant women are strictly not recommended to eat undercooked pork and lamb (“meat with blood”).

When should you take a blood test for worms and helminths?

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Penetrating into the human body in the form of eggs, parasitic worms usually settle in the gastrointestinal tract. Helminths interfere with the absorption of nutrients and destroy the cells of the intestinal mucosa. This causes inflammation, cysts and secondary infectious processes. In addition, parasites secrete toxic waste products that cause general weakening of the host’s body.

Some types of worms also affect the liver, lung muscles, brain, and visual apparatus. All this is manifested by characteristic signs. A blood test for worms should be taken if the following symptoms appear:

• digestive disorders - diarrhea, constipation, vomiting, accumulation of gases in the intestines;
• dramatic weight loss while maintaining your usual diet;
• insomnia;
• anxiety, sudden mood swings, general weakness;
• rash, inflammation, irritation of the skin and mucous membranes;
• deterioration of hair and nails;
• debilitating cough;
• decreased immunity, frequent colds;
• hemorrhoids, pain and burning in the anus.

It is recommended for people at risk to undergo testing for helminthic infestations regularly:

• People in contact with pets.
  This category includes pet owners, veterinarians, circus and zoo workers. Animals are one of the most likely sources of infection with helminthic infestations.
• Residents of areas with a high threshold of infection.
  Helminthiasis is especially common among residents of tropical and subtropical countries.
• Doctors and medical staff.
  There is a high risk of helminthic infestations among parasitologists, virologists, proctologists, and pediatricians.
• Workers of cafes, bars, restaurants.
  Cooks and kitchen staff are constantly in contact with unwashed vegetables, and waiters touch customers' dishes.
• People working with children.
  Kindergarten teachers, primary school teachers, and sports section coaches are at risk for helminthiasis.

By regularly conducting laboratory diagnostics, you can identify parasitic infestations in the early stages and avoid serious health consequences.

Myth No. 2. Symptoms of toxoplasmosis are similar to flu symptoms

Actually: YES

Infection with toxoplasmosis can be asymptomatic, but quite often in the early stages it causes flu-like symptoms (chills, sudden fever). The acute period can end in a few days, or can last up to several months. Therefore, if you think that you are sick and cannot be cured, get tested for toxoplasmosis to eliminate the risk of infection.

Once in the human body, Toxoplasma oocysts and tissue cysts penetrate macrophage cells in the intestine and “travel” through the blood throughout the body. Toxoplasma can become fixed in the liver or spleen, lung tissue, and cardiac muscle tissue with the formation of clusters. These accumulations persist in the body for up to several decades, sometimes for life.

The chronic stage of toxoplasmosis occurs latently and is most dangerous for people with weakened immune systems (pregnant women, HIV, hepatitis, chronic inflammation), as it can cause toxoplasma encephalitis, which is fatal.

What types of worms can be determined by a blood test?

To prescribe effective treatment for helminthiasis, it is important to correctly determine the type of parasite. The three most common types of parasitic worms are trematodes, cestodes and nematodes. Each group of parasites has several hundred varieties of helminths.

An enzyme immunoassay test allows you to determine antibodies to the following types of parasitic infestations:

• Ascariasis.
  Roundworms are roundworms that enter the human body in the form of eggs. The carrier of roundworms becomes the main source of infection for others, since the eggs of the worms are excreted along with the patient’s feces. Settling in the human intestine, roundworms grow quickly and can penetrate the vascular bed. Next, the worms penetrate the tissues of the liver, lungs and respiratory tract. Patients experience general malaise, stool upset, shortness of breath, and chest pain. The lifespan of a roundworm is one year, after which the dead individual is excreted from the body along with feces. The primary diagnosis of ascariasis is the detection of eggs in the patient's stool. However, an accurate diagnosis is made by determining specific antibodies (IgG) to roundworms in the blood.
• Toxocariasis.
  This disease is caused by the nematode Toxocara canis. These parasites usually live in dogs and wild animals. Penetrating into the soil with animal feces, nematodes can enter the human body by eating unwashed vegetables and not following hygiene rules. In the body of the carrier they affect the intestines, liver, and lungs. It is difficult to diagnose toxocariasis by examining stool, since nematodes do not survive to adulthood in the human body. In this case, it is possible to identify these worms using a blood test to detect antibodies (IgG) to Toxocara antigens.
• Opisthorchiasis.
  This parasitic disease is caused by small trematodes of the family Opistorhidae. They enter the human body when eating raw or uncooked fish from the carp family. In the human body, trematodes settle in the bile ducts and pancreatic canals. Here they can parasitize for many years, causing illness, weakened immunity, allergic reactions and secondary infections. Specific IgG antibodies to opisthorchis antigens can be detected in the patient’s blood 6-8 weeks after the parasite enters the body.
• Trichinosis.
  Helminth infections of this group are caused by nematodes of the genus Trichinella. Infection occurs when eating raw meat containing Trichinella larvae. The danger of nematodes of this group lies in the fact that they mature in the body and lay new larvae. They are able to penetrate the vascular bed, from where they are distributed throughout the body. Especially often, Trichinella larvae settle in the cells of striated muscles. This causes pain and muscle aches, fever, and general weakness of the wearer. Specific antibodies to trichinosis (IgG) appear in the blood 14–15 days after helminthic infestation.
• Echinococcosis.
  This parasitic disease develops when the larvae of Echinococcus spp. enter the body. Most often, the parasite enters the host’s body from a dog. The risk group includes people who regularly come into contact with pets. Echinococcosis is a tissue disease in which the pathogen attacks the cells of internal organs. Only an enzyme immunoassay blood test will show worms of this type by the appearance of class G antibodies.
• Strongyloidiasis.
  This is a tropical helminthiasis caused by the roundworm Strongyloides stercoralis (eelworm). You can become infected with the larvae of this helminth through direct skin contact with contaminated soil, for example, by walking barefoot. The disease is often asymptomatic, causing severe forms of immunosuppression. In the blood, specific antibodies to Strongyloides stercoralis appear 2 weeks after infection and persist for 6-12 months after recovery.

Only if there are no antibodies in the patient’s blood to all types of parasitic infestations can we speak of the absence of helminthiasis. If antibodies to one or more helminths are detected, the patient is referred to a parasitologist for effective treatment.

Myth No. 3. Common flies carry amoebiasis pathogens

Actually: YES

You can become infected with amoebiasis through dirty hands, as well as through direct contact with a carrier of cysts (a special form of the pathogen). Common flies also participate in the spread of cysts; they are mechanical carriers.

Dysenteric amoeba (Entamoeba histolytica) is widespread. This microscopic protozoan lives in both water and soil and “survives” on the skins of fruits and vegetables.

Consisting of just one (!) cell, the amoeba can cause irreparable damage to health. In a weakened body, during infection or hypothermia, it turns into a dangerous pathogenic form. By secreting a special proteolytic enzyme and causing intestinal ulcers and bleeding, it thereby obtains “food” for itself - erythrocytes (red blood cells). Therefore, against the background of amebiasis, anemia and general intoxication often develop.

The habitat in the human body is the lumen of the large intestine and its walls. However, with the bloodstream, amoebas can spread throughout the body and be localized in the lungs, brain and even in the skin.

Most often, amebiasis occurs in countries with hot and warm climates (Middle East, countries of Southeast Asia). In this case, it is recommended to follow simple protection rules:

• wash your hands and disinfect them;
• eat peeled vegetables and fruits, without skin;
• drink only (!) bottled water.

Myth No. 4. Giardiasis affects the gallbladder

Actually: YES

Like amoeba cysts, Giardia cysts can remain active for a long time on poorly washed vegetables, fruits, herbs, in water (up to 70 days) and even in dust. Flies can also be carriers of giardiasis: therefore, in the summer, at the dacha or on vacation, do not leave food uncovered.

The main targets of Giardia are the gallbladder, duodenum and small intestine. By blocking the mucous membrane, protozoa literally inhibit the normal digestion process. The food is not digested, and the processes of rotting and proliferation of bacteria and yeast begin.

As a result, the symptoms of intoxication increase, the absorption of nutrients - proteins, fats, carbohydrates - is disrupted, which can lead to exhaustion.

The ELISA method can be used for diagnosis:

1. Viral diseases:

• HIV infections;
• viral hepatitis;
• cytomegalovirus infection;
• Epstein-Barr virus;
• herpetic infection;
• coronavirus disease.

1. To diagnose sexually transmitted infections:

• syphilis;
• chlamydia;
• trichomoniasis;
• gonorrhea;
• ureaplasmosis.

1. Hormone levels in endocrinology.
2. Autoantibodies and cancer markers in oncology.
3. General IgE and specific IgE antibodies in allergology.
4. Medicines, drugs in biological samples.
5. Serum proteins (ferritin, fibronectin, etc.).

Myth No. 5. With a parasitic infection, a person rapidly loses weight

In fact: NOT EXACTLY SO

With a parasitic infection, there may be no symptoms at all or they will not be obvious. The main symptoms that should alert you include repeated episodes:

• nausea;
• diarrhea;
• stomach ache;
• general state of weakness;
• frequent lack of appetite.

When infected with tapeworms, allergic reactions (rashes, itchy skin), increased body temperature, and neurological problems such as seizures often occur.

With a nematode infection (roundworm, whipworm, trichostrongylidae, duodenal worm, tominx, necator), a skin rash, itching, fatigue, and a condition characteristic of anemia appear. With trichinosis, swelling of the face is often noticeable, muscle pain is felt, increased sensitivity to light, and conjunctivitis may occur.

Myth No. 7. To diagnose parasites, you can only donate blood

Not really

To diagnose a parasitic infection, blood is used (to detect antibodies to the pathogen) and feces are used for microscopic examination for worm eggs and protozoa. It is carried out in the usual way and by the enrichment method (PARASEP system). Stool analysis using the enrichment method (PARASEP system) is more sensitive, which makes it possible to identify the most difficult parasites to diagnose - for example, opisthorchid (very small eggs) and protozoa (amoebas).

If you suspect a parasitic infection, as well as to assess the effectiveness of antiparasitic treatment in case of infection, at CITILAB you can perform all the necessary diagnostic tests:

• Examination of stool for protozoa and helminth eggs (microscopy)
• Examination of stool for protozoa and helminth eggs using the PARASEP system
• Antibodies to Toxoplasma gondii IgG (the causative agent of toxoplasmosis)
• Antibodies to Toxoplasma gondii IgM
• Antibodies to Giardia lamblia (giardia) total
• Giardia lamblia antigen in feces
• Antigen of protozoa (giardia, amoeba, cryptosporidium) in feces

Blood is donated on an empty stomach or no earlier than 8 hours after eating. It is not recommended to smoke or drink coffee for half an hour before taking blood. You can drink still water.

72 hours before submitting stool for examination, avoid taking laxatives, rectal suppositories, oils, medications that affect intestinal motility (belladonna, pilocarpine) and the color of stool (iron, bismuth, barium sulfate).

What analysis shows the presence of worms?

Blood tests are usually done to confirm the results of stool tests, which often give false results. To determine the presence of worms using a blood test, the following types of laboratory tests are performed:

• General blood analysis
  . With worms in the patient's sample, there is an increase in white blood cell levels and a decrease in hemoglobin. An increase in eosinophils and ESR may also indicate parasitic infestation. This study does not allow us to accurately determine the fact of helminthic infestation.
• ELISA (enzyme-linked immunosorbent assay).
  This study is based on the antigen-antibody reaction. If there are helminths in the patient’s body, the immune system produces specific immunoglobulins (antibodies) to them. A blood test for antibodies to worms allows you to accurately determine the fact of infection, as well as determine the type of parasite. IgG, IgA, and IgM antibodies are used as the main indicators of helminthic infestation. An ELISA test allows you to determine the presence of several parasites in the host’s body at once.

Sometimes liver tests and PCR diagnostics are additionally performed to confirm the diagnosis.

How to Prevent Parasitic Infection

• Do not eat raw or undercooked animal and poultry meat (pork, lamb).
• Store meat separately from other foods, even in the freezer.
• Use separate cutting boards for meat and fish. Disinfect them regularly, and also sanitize the countertops on which you prepare these products.
• Avoid walking barefoot in areas where the soil may be contaminated with feces.
• Always wash your hands before eating and after using the restroom.
• Rinse vegetables, fruits and herbs well in running water.
• Limit contact with stray animals.

Be healthy!

Author:

Baktyshev Alexey Ilyich, General Practitioner (family doctor), Ultrasound Doctor, Chief Physician

Preparing for a blood test for worms

Before donating blood for helminthic infestations, no special preparation is required. To increase reliability, doctors advise following the following recommendations:

• stop eating 4-5 hours before the test;
• on the eve of the test you should not drink alcoholic beverages;
• It is advisable to exclude spicy, salty, and sour foods from the diet in two or three days;
• you should not take antihelminthic therapy (in consultation with your doctor);
• Avoid heavy physical activity one day before submitting biological material.