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Eggs of Ascaris
Last reviewed: 23.04.2024
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Ascaris eggs are both a factor of infection, and the subject of diagnosis. There are some characteristic features of the appearance of the eggs of ascarids, as well as some features of their resistance to environmental conditions, which allows to take this into account when diagnosing and preventing ascaridosis.
[Some features of the appearance of the eggs of Ascaris
Eggs - this is exactly the factor with which the person is infected. The ways of transferring the eggs of ascarids to humans are limited mainly to the fecal-oral mechanism. This is due to the fact that the ascarid is geogelmint and in the external environment the eggs are stored in the ground. Therefore, the infection occurs with unwashed hands, with poorly processed food, as well as unwashed vegetables and fruits. Also, the risk of transmission of infection can be water, which contains eggs when it is taken in raw form. Getting into the intestine, the egg is activated and the cycle of development of the ascaris begins.
- How do the ascarid eggs look like?
They are small in size - about five to seven micrometers. These eggs are well protected from adverse environmental factors by five shells. Externally, the eggs have an oval shape, and as for the unfertilized, the shape can be spherical or round.
The color of the shell eggs is brown or dark yellow, which corresponds to the stain color. The outer membrane is protein, it does not always exist and under normal conditions it is transparent, but only colored in such color from feces. Next comes a thick three-layered shell, which together with the protein fulfills a protective function, because for a long time the eggs are in the external environment. The third layer of the wall structure of the eggs of ascarids is a lipid ball, which is the thinnest and ensures the exchange of nutrients in the embryo. Further in the center is the embryo-blastomer.
If the egg is unfertilized, then there is no embryo, and there are only shells. This structure provides resistance to eggs in the external environment. But for the normal development of eggs, optimal conditions are needed - temperature, soil moisture, in which these eggs are stored. The most optimal conditions are a soil moisture of about ten ppm, and the temperature of the environment should be from ten to thirty-five degrees of heat. At this temperature, eggs actively grow and larvae are formed already in the human body. Also, to achieve sufficient invasiveness of eggs, it is necessary that there is sufficient air and oxygen, because the parasite is very fond of oxygen. Therefore, eggs are stored on the outer cover of the soil and so easily fall on food.
- At what temperature do ascarids die?
Speaking about the lowered temperature, during the day the eggs die at a temperature below thirty degrees below zero. That is, under the cover of snow with a slight frost, the eggs of ascaris can safely last for months. More sensitive eggs ascarid to high temperatures - at the boiling point of water (100 degrees) eggs die instantly. Therefore, it is important not only to heat the water to a hot state, but to boil it for at least a few seconds - it prevents the disease with ascariasis.
It is also necessary to know that a female can lay up to two hundred thousand eggs at a time, but not all of them are viable, so it is important to diagnose pathology in time and not allow it to spread quickly.
Features of diagnosis and treatment of ascaris eggs
The detection of ascaris eggs is a very difficult task. This is due to the small amount of the particle that can be detected in the stool, because some of them circulate in the intestine without secretion. Therefore, for diagnostics, sometimes it is required to repeat the tests several times for one positive result.
The eggs of the roundworm in the feces under the microscope have a characteristic appearance - an oval shape, a thick shell and a dark yellow or brown color. This diagnosis is often difficult, because there may be many unfertilized ascarid eggs that are difficult to differentiate. Therefore, there is often a need for additional diagnostic methods. Use light microscopy, in which the stool is stained with a special luminescent paint and when eggs are present they glow under a microscope. It is also possible to detect the presence of eggs and antigenic material in feces and other biological fluids (blood) using a polymerase chain reaction.
The eggs of ascarids in children are found very often, because children have the most contact with sand and unwashed hands. The peculiarity of the course of this pathology in children is very complicated treatment because of the frequent reinfection, in connection with active games and contact with other children. Therefore, they often identify eggs in the stool after treatment, which can not be used as a control over the quality of treatment.
Levamisol (Decaris) is a very common preparation for the treatment of helminths. It has a wide range of actions, including on ascarids. The drug acts by affecting the muscular layer of the wall of the worm and disturbing its normal motor activity, which leads to the death of the individual.
- But does Decaris kill ascarid eggs?
Given the mechanism of action of the drug, it can be said that it is active only against adult worms that are at the stage of intestinal invasion. Therefore, the use of the drug for the treatment of eggs will not lead to complete recovery. In this case, the use of those forms that have activity against all forms of existence of ascarids, for example albendazole, is recommended.
The eggs of ascarids are allocated by the sick person to the external environment and are a factor in the transmission of ascariasis to another person. For the high invasiveness of such eggs, optimal conditions for their existence are necessary, therefore, given the sensitivity of eggs to high temperatures, this can be used for the purpose of prevention. For the destruction of eggs, it is necessary to select drugs that act on all forms of existence of ascaris - this increases the chance of complete recovery.