Table of contents:
Video: Analysis For Echinococcus And Its Structure: Antibodies And The Final Host
1 What is echinococcosis?
1.1 Life cycle
- 2 Diagnosis of echinococcosis
- 3 Laboratory analyzes
A rarely diagnosed parasitic disease with a chronic course in our country is called echinococcosis. The disease appears due to infection by the larvae of Echinococcus granulosus (tapeworm). This ailment is most common in southern countries. Our article will consider the features of this disease, the echinococcus cycle, as well as the nuances of diagnosing the disease.
What is echinococcosis?
The causative agent of echinococcosis is the tape type of worms. Sexually mature individuals, namely tapeworm echinococcus, parasitize only in the body of representatives of the canine family (wolves, dogs, jackals, foxes). They are the ultimate hosts of the parasite. Echinococcal cysts are found in intermediate hosts, which are ungulates and humans.
If we talk about echinococcus, the structure of this parasite is as follows: the worm up to 5 mm long and up to 0.7 mm wide consists of a pear-shaped head (scolex), a neck and several segments. There are 4 suckers and two rows of hooks on the head. One of the segments is hermaphroditic, and the other is mature and has a uterus filled with eggs in the form of a six-hooked oncosphere.
Echinococcal cyst is a bladder with a complex structure. Under the outer multilayer shell is the embryonic membrane. It is she who produces daughter vesicles, brood capsules, and also ensures the growth of the lamellar shell. The liquid contained in the capsule contains brood capsules and scolexes, there may also be daughter bubbles, but sometimes they form outside the capsule.
It is these capsules that form in humans. Man, as an intermediate host, acts as a biological dead end for the parasite. The final owner of echinococcus in humans is a domestic dog. An animal becomes infected by eating the carcasses of infected animals.
Ways of infection with human echinococcus can be different:
- Most often, human infection occurs through contact with domestic dogs, if helminths are present in their body. On the tongue and wool of such animals there are many eggs and tapeworms of echinococcus.
- Also, human infection can occur from a healthy animal that is a carrier of helminth eggs. The eggs of the parasite fall on such dogs during their contact with a sick animal.
- It is possible that people become infected through unwashed berries, vegetables, fruits, herbs.
- Infection can also occur from wild carnivores in the process of hunting, cutting or eating skins.
- In regions with developed sheep breeding, shepherds, shepherds, shearers and members of their families are at risk of infection.
What is Toxoplasma gondii and its life cycle
Echinococcosis develops during the introduction and growth of the larva in one of the organs. In this case, several stages of the development of the parasite are distinguished. Most often, oncospheres affect the human liver, and infection occurs through the oral route. In the event of the appearance of multiple cysts, the structure of the organ changes, its functions are disrupted.
From the moment it enters the body of the primary host, the following stages of echinococcus are distinguished:
- The parasite that lives in the canine family reaches the mature stage. At this stage, eggs ripen in a mature segment, after which it is separated from the body of the helminth and is excreted along with feces.
- Here the segment is torn, inseminating the grass and the whole environment with its eggs. Echinococcus eggs can cling to the fur of animals or enter their body when eating grass.
- After the penetration of the oncospheres into the host organism, gastric juice dissolves the egg shell and releases the embryo of the parasite. With the help of hooks, it is introduced into the gastrointestinal tract, penetrates into the bloodstream or lymph and is carried throughout the body.
- The embryos settle in the liver, lungs, muscles or kidneys and develop into a larva. By the end of the second week after infection, the larva acquires a vesicular structure.
- Six months later, the bubble reaches a diameter of 0.5 cm, the parasite begins to multiply. Education grows gradually and very slowly. Sometimes after 25 years, about 10 liters of liquid is placed in a grown capsule. The cystic cavity is filled with yellowish liquid contents.
Diagnosis of echinococcosis
To diagnose the disease, it is necessary to carry out tests for echinococcus. Based on the clinical symptoms of the disease, the specialist can prescribe various instrumental and laboratory tests. A preliminary survey of the patient about his place of residence, type of activity and time of manifestation of the first symptoms will help the doctor make preliminary conclusions about which worm could provoke the disease.
Before doing an analysis for echinococcus, a specialist may prescribe an instrumental examination that will help assess the severity of volumetric processes in the affected organs of the retroperitoneal space or abdominal cavity, as well as the localization of the infection. Often, cysts can be detected in the liver, lungs, brain, kidneys.
If the abdominal cavity or other organs are damaged, the following examinations are prescribed:
- CT scan is done to detect cysts in different organs with deep localization;
- Ultrasound is indicated for echinococcosis of the liver, kidneys and other organs of the abdominal cavity (cystic formations or an enlarged liver can be detected);
- MRI is performed if there is a suspicion of brain damage;
- X-ray is shown in case of lung damage (in the picture you can see cystic formations in the organ);
- laparoscopic examination.
If you suspect the presence of helminthic invasions, an analysis is made for echinococcosis. It helps not only to confirm the diagnosis, but also to identify the intensity of the process and the degree of damage to internal organs.
How to take a stool test for opisthorchiasis?
First of all, it is necessary to donate blood for echinococcus. At the same time, specific antibodies to echinococcus are detected in the blood or other physiological fluid. You can test blood for antibodies to echinococcus by the following methods:
If a person has echinococcosis, a general blood test will also help to make a preliminary conclusion about the presence of the disease. So, if the value of the following indicators differs from the norm, then we can assume the presence of an ailment:
- Eosinophilia. The normal concentration of eosinophils should not exceed 5%. When parasites enter the human body, this indicator rises sharply.
- With inflammatory processes and the introduction of an infection into the body, ESR always increases. The rate for this indicator is 2-15 millimeters per hour.
The most informative technique is considered to be ELISA (enzyme-linked immunosorbent assay), which detects antibodies to echinococcus antigens in the blood. For analysis, blood is taken from the patient from the cubital vein. The procedure is performed on an empty stomach on an outpatient basis.
Depending on the concentration of the antibody titer, the analysis is decoded:
- if antibodies to echinococcosis igg are not higher than 1/100, this indicates the absence of helminthic invasions;
- the result is positive if the titer is 1/100 or higher. In this case, they talk about infection.
But it should be borne in mind that there is a false positive result. More often this is observed in somatic diseases accompanied by pathologies of those organs where echinococcus can live, for example, oncology of any organ, cirrhosis, tuberculosis. A positive result is observed with other helminthiasis (fascioliasis, opisthorchiasis, cysticercosis, etc.).
If, against the background of a negative result, the symptoms of the disease persist, then after a while you need to be tested again. This usually happens at the onset of the disease or at a moderate intensity of the process. In this case, it is necessary not only to retake the analysis, but also to use other diagnostic techniques to identify the type of causative agent of the disease.
Serological studies allow not only to confirm the diagnosis, but also to evaluate the effectiveness of treatment. If in the course of repeated studies it is revealed that the indicator of immunoglobulins of the IgG type decreases, then this indicates the correct treatment and the patient's recovery.