Does the gadfly lay larvae when it bites a person. Gadfly larvae in the human body: where do they come from under the skin and why are they dangerous? The life cycle of an insect looks like this
It is dangerous because it bites almost imperceptibly, quickly laying larvae under the skin, which immediately begin to develop, which leads to various inflammations. An unpleasant situation in general. Worst of all, when they get into the eyes or head of a person, then a complex operation is required to remove them.
There are also deer, horse, sheep, stomach, nasopharyngeal and other gadflies. Each species chooses certain mammals for itself. In addition, some insects prefer to lay their larvae on the back and sides of animals, while others prefer the groin and inner side legs, and still others choose the nostrils, ears and lips of unfortunate victims.
In appearance, the gadfly is a little smaller than horseflies. They have large compound eyes, a fluffy body and transparent wings. Unlike the latter, they do not drink blood and bite solely in order to lay eggs. Although not all types of gadflies resort to bites. For example, some females carefully attach the eggs to the hairs of the victim, others may leave them on the grass in the hope that sooner or later the cattle will swallow them with food.
And there are completely original subjects - these and animals do not need to be looked for. They just fly to where there are a lot of mosquitoes, find a suitable specimen, put it in a friendly hug and gently leave their egg on its back. A mosquito (or, more precisely, a mosquito) serves as an excellent vehicle, which will deliver the larva to its destination in time.
Here the most interesting begins. Rather, the most unpleasant for livestock. As a rule, the larva leaves the egg within 3-7 days. Moreover, hot weather of the order of 30-32 degrees is considered optimal for its development. Wasting no time, the insidious invader penetrates the body of the poor fellow owner. Where exactly she goes is not exactly known, but the animal suffers greatly from this and loses weight.
For further growth the larvae need oxygen, so they form fistulous holes in the skin. Through them, they then get out, where they fall to the ground and pupate. Imago emerge from the pupae literally in 2-3 seconds, and after a minute they can already fly and mate. In total, the development cycle of the larva lasts about a year.
There is no need for adult gadflies to eat: they live off those nutrients that have accumulated in the larval stage. True, such a supply is not enough for a short time - according to various sources, adults live from three to twenty days. It is curious that their lifespan depends on the weather: if the days are clear and hot, then the gadflies quickly find their soul mate and lay their eggs. If the days are rainy, they are able to sit in the grass for several days, waiting for the right moment. At the same time, all processes in their body slow down, which can significantly reduce energy costs.
Female gadflies are very prolific - one such lady is able to lay up to five thousand eggs. Of course, every future mother tries to protect her offspring and “distribute” the kids to different “kindergartens”, because if they are all placed on one animal, it can simply die, and this cannot be allowed.
Interestingly, unfortunate victims always feel the approach of gadflies. They begin to shake their heads, beat their tails, or try to get out of dangerous place. How they distinguish them from simple flies remains a mystery.
The first type is dangerous for both humans and animals. With untimely treatment, disastrous consequences are possible.
The second type is characteristic of He, of course, is not dangerous, like the first type, but still, if this happens, boils form on the body of a person or animal. In addition, there are severe pains. After that, pus may be released.
The cavity type is most common in goats. The larvae are first in the nostril, and then penetrate into the respiratory tract.
An adult gadfly larva is a fly. Its size is about 2 cm. It is somewhat similar to a bumblebee.
But in order to distinguish it from this insect, there are a number of signs:
- big head;
- large eyes;
- blue belly;
- orange paws;
- transparent wings.
Half a minute after the exit, an adult gadfly can fly. The female produces about 600 eggs. But, fortunately, only 1/6 of it survives.
On the territory of our country there are about 7 species of larvae. They mostly live in the body of cattle. There are cases when gadfly larvae were found in the human body in Russia. Their favorite place where they prefer to be is the eyes or the skin.
The gadfly larva in a person can be anywhere. For example, it can be found on the arm, and on the chest, and on the leg, and even on the head. But their favorite habitats are the armpits and back. It also happens that the gadfly larva in the body is located in the nose or eye.
After that, the person's condition sharply begins to deteriorate. Nausea or vomiting, weakness and dizziness, muscle pain are the main symptoms of the penetration of the gadfly larvae into the body. In the area where there is inflammation, the patient may feel something moving.
The penetration of larvae into the vitreous body of the eyeball is very dangerous. Then a person can lose sight altogether.
- headache;
- deterioration of the sense of smell;
- swelling of the nose;
- pain at the location of the larva.
Surprisingly, these harmful microorganisms can crawl out through the nostril.
How is the diagnosis made?
The main method is the delivery of a blood test. It determines the amount of antibodies. The patient is also asked a series of questions. For example, they ask if he was in places where the disease is common. In addition to all this, the specialist conducts a visual inspection. Using this method, you can detect an inflamed purulent abscess. It has a hole through which air flows. The doctor examines the place with the help of a special device, namely a magnifying glass.
If you are sure that there are gadfly larvae in the body, then you should not contact a therapist, but immediately contact an infectious disease specialist.
How is the treatment for infection with larvae?
Removal of gadfly larvae: how does it happen?
A complex operation should be performed only by a specialist. The gadfly itself is located in the very deep layers of the epidermis. As mentioned above, there it is located thanks to the hooks. If the patient himself tries to perform this entire procedure, then it is possible that part of the larva will remain under the skin. With this outcome of events, suppuration and an inflammatory process will follow.
As soon as the operation is completed, an antiseptic bandage is applied to the place where the abscess used to be.
Infection prevention
But most often under the skin of a person, the gadfly larva penetrates precisely in countries with a tropical climate. And if you decide to go there, then observe a few simple rules. Avoid places where a large number of insects live. Of course, you need to wear clothing that will protect against bites. Now in stores huge selection good repellents. They should be used too.
If, nevertheless, for example, an insect has bitten you, you should not panic ahead of time, but you should not forget about it either. First, the wound should be treated disinfectant. And watch her. If something went wrong, you should immediately contact a specialist. The doctor will examine you, if the diagnosis is confirmed, he will send you to the appropriate procedures, and if the opposite is true, you can safely return home. And don't forget that vigilance never hurt anyone.
The most common cause of the spread of the disease is the consumption of low-quality meat. As soon as a market trader turns away, a tidbit is instantly covered with a hungry flock of flies, leaving their larvae on food. Then these larvae migrate to the main dish (especially if the meat is cooked for an insufficient amount of time or at insufficient temperature).
The main danger of such a disease is the ability of arthropods (flies belong to this class of insects) to penetrate the skin almost asymptomatically and lay eggs in any part of the body. Often, doctors are faced with the need to eliminate insect larvae from the eyes, ears, wounds or upper layers epidermis.
Depending on where exactly the main part of insect larvae is localized, the disease in humans is usually classified into several types.
Depending on the type of insect and the method of penetration into the human body, the disease is classified into:
Most often the larvae arthropod insects enter the human body by accident. Flies can lay their larvae on household appliances, gastronomic products, garments. So the ingestion of insect eggs occurs unconsciously. There are times when the larvae can crawl under the skin from clothing items through an open wound.
Depending on the affected organs and tissues, the disease in humans (see photo) is classified into:
Depending on how deeply the fly larvae penetrate the skin, this type of myiasis is divided into:
- epidermal;
- subcutaneous with a predominance of larvae in the connective tissue;
- directly subcutaneous.
More details on what skin myiasis looks like can be found in the photo.
Cutaneous myiasis epidermal.
In epidermal myiasis, fly eggs penetrate only the upper layers of the skin. Most often, this phenomenon is characteristic of infection with gadfly larvae. How it looks, look at the photo.
If the larvae make their way into the deeper layers of the skin and occupy areas connective tissue, one has to deal with the corresponding subcutaneous myiasis. This type of myiasis disease in humans is caused by the penetration of fly larvae and skin gadflies under the skin. Feature diseases - a small tumor that can change its location. Pimples often appear on the surface of the skin, resembling boils.
Cavity myases. Formed when insect larvae enter the soft tissues and body cavities with their further destruction.
And finally, a special kind of disease - eye myiasis. You can see it in more detail on the photo. The best outcome for a person is if the gadfly or fly larva is introduced into the conjunctival sac of the eye (upper eyelid area). Most dangerous case when insect eggs are diagnosed in the eyeball.
Symptoms of the disease
On initial stages, especially if the larvae have entered the skin of a person, there may be no symptoms. In the future, as the larva develops, small tubercles the size of a pea can form under the skin. Gradually, they increase in size and take the form of a local tumor. characteristic feature The thing that has to be dealt with in myiasis and not in any other disease is that in myiasis the tumor can travel under the skin.
Symptoms may vary depending on the location of the larvae. If you have to deal with skin myiasis, the appearance of a tumor may be accompanied by the formation of small pustules resembling boils.
If the larvae enter the human digestive tract (for example, when they are accidentally eaten with meat products), the course of the disease may be accompanied by symptoms characteristic of ordinary food poisoning. Nausea, vomiting, weakness, lethargy, apathy, sharp pains in the stomach, colitis are the most common signs of the disease. That is why it is often confused with a commonplace eating disorder and inadequate treatment is used.
The most important danger of myiasis is the rapid progression of the disease, since the larvae very quickly take root in the body of the victim and begin to grow. On average, their sizes can vary from the size of a small pea to a tumor with a diameter of up to 5 centimeters.
If these are gadfly larvae, most often patients are treated for intestinal diseases. IN this case we are talking about such a variety of myiasis as gastrofilosis. True, this type of disease occurs mainly in artiodactyl animals. The speed of penetration of the larvae into the internal organs is amazing - it can reach up to several tens of centimeters per day. The main goal of gadfly larvae is penetration into the stomach and intestines.
If another type of gadfly (the so-called "tropical" gadfly) enters the animal's body, abscessing areas, or nodes, form in the skin. Their sizes also increase very quickly. Another type of disease, the carrier of which are tropical flies, is cordylobiosis. The clinical picture during the progression of this disease is similar to the previous case. However, in the first case, the disease is called "dermatobiosis", and in the second - "cordylobiosis".
What to do?
In order for the larvae to leave the body on their own, special rubbing is used. For them, chloroform is usually used (if we are talking about damage by larvae skin), means for washing (if we are talking about the penetration of larvae into the stomach), drugs with anthelmintic properties (if you have to deal with intestinal damage).
Summary. Myiasis is a disease of the skin or internal organs, provoked by the penetration under the code of the larvae of various arthropod flies - indoor, meat, cheese or gadflies. The larvae develop and grow very quickly. In some cases, the speed of their movement under the skin can be up to several tens of centimeters per day. It is necessary to treat the disease with the help of means that promote the removal of larvae from the body (various compresses), as well as anthelmintic drugs.
Appearance
Not everyone knows what a gadfly looks like. Gadflies are insects with one pair of membranous front wings. The head is semicircular, very mobile, connected to the chest by a thin stem. Mouth organs are absent, as adults do not feed. 1 pair placed on the head compound eyes and 3 simple eyes. There are short antennae on the forehead. Gadflies have 3 pairs of legs, the hind legs are slightly longer than the front ones. The body is covered with long and short hairs, as well as bristles. These insects live everywhere and mostly near humans. These insects feed on liquid food: blood and other body nutrients. Only larvae feed, and adults are devoid of mouthparts, so it is a delusion that an adult gadfly feeds.
Development cycle
After mating, the female chooses a place to lay her eggs. These are usually grazing areas. livestock or stall, farm. The female lays eggs on fodder plants or animal fur. Then the hatched larvae enter the animal's esophagus and develop there or penetrate under the skin. This cycle of development goes through the stomach and skin gadfly. The cavity does not lay eggs, but on the fly gives birth to larvae that enter the mouth, eyes and nose of animals.
The gadfly is divided into 3 families:
- Gastric gadflies (Gasterophilidae)
- Hypodermic gadflies (Hypodermatidae)
- Cavity gadflies (Oestridae)
Gastric gadflies are characterized by the fact that the female lays eggs on the animal's fur, on its fodder plants. After hatching, the larvae of the gadfly enter the body of the animal with food or are introduced under the skin. In the stomach, they reach full maturity and pass out with feces. The larvae that enter through the skin make khoy in it, trying to get to the stomach. This causes intense itching and inflammation.
The most famous representative of this family is the horse gadfly ( Gasterophilus intestinalis).
Horse gadfly - Gasterophilus intestinalis
horse gadfly
Representative of the family of gastric gadflies. It lives everywhere and belongs to synanthropic insects (whose life activity is associated with humans). The body of the gadfly is slightly pubescent, reaches 16 mm in length. The thoracic region and abdomen are yellow-brown in color, the end of the body is black. The head is light, almost white. There are short antennae on the forehead. Females differ from males in that they have a long ovipositor that folds under the body. The horse gadfly is an insect that lays eggs on the fur of animals or plants that they feed on. Next, the larvae emerge from the eggs and try to get to the esophagus, through the skin or through the mouth. The horse gadfly is often called the hook gadfly, since its larvae have several rows of hook-like spines with which they cling to the mucous tissues of animals. Feeding on the blood of warm-blooded animals and other nutrients, the larvae go through three stages of development. Having reached 2 cm of body length, they come out along with feces. The larvae pupate in the faeces. After 30-45 days, adult gadflies emerge from the pupae.
Hypoderma bovis
Dermatobia hominis
Means of protection against gadflies
As we have already said, adults do not have mouthparts, do not feed and do not sting. They have enough of the supply of nutrients that they have accumulated in themselves in the larval stage. But when the larva pierces the skin, it can be conditionally called a bite. Having found a gadfly bite, treatment should not be postponed. Of course, it is best to immediately consult a doctor, but if this is not possible, then you can try to remove the larva yourself. First of all, you need to take a thick, sticky or greasy agent (adhesive tape, petroleum jelly, PVA glue) and apply it to the gadfly bite. In this case, oxygen will not enter the chamber and the larva will partially crawl out. Next, you need to carefully pull out the larva, without crushing or tearing it. A gadfly bite precedes swelling, swelling, and infection of the skin, so it is necessary to disinfect the wound. Below are photos that show the bite of a gadfly and the consequences that it causes.
As for animals, it is necessary to carry out regular inspection of livestock. If larvae are found, it is necessary, again, to lubricate the injury site with petroleum jelly (or other means). Then you need to carefully remove the larva so that it does not rot and cause skin infection. At the end, be sure to treat the gadfly bite with an antibacterial agent.
Among over 150 species of gadflies, only one, called Dermatobia Hominis, is dangerous to humans. It cannot be found in Russia and the CIS countries - the insect is found only in countries with a tropical climate: Central America, Argentina and in some parts of Mexico. A gadfly larva in a person can cause a lot of unpleasant phenomena: inflammation, suppuration, disruption of the normal functioning of body systems, and surgical intervention may be required to remove it.
How can a larva enter the body?
An adult gadfly is a fly, the size of which does not exceed 18 mm. It has a large head with large eyes located on it, a blue abdomen, painted in Orange color paws and transparent wings. Because of the hairs all over the body, the gadfly resembles a bumblebee.
An adult insect throughout its brief life does not feed on anything, but uses the nutrients accumulated in the larval phase.
30 seconds after the exit, the adult gadfly becomes capable of flight and reproduction. One female can produce up to 700 eggs, but the larva appears from only 1/5 of them.
Female human gadfly with eggs
The female catches mosquitoes, ticks and almost 40 species of other blood-sucking insects and lays eggs on their abdomens. At the moment when the insects land on human skin, the larvae, feeling warm, hatch from the eggs and move to the skin, into which they are subsequently introduced. Penetration into the body is not accompanied by any painful sensations, and most often remains unnoticed by a person.
About 6 species of gadfly are common on the territory of Russia, and all of them prefer to choose a large one as their host. cattle or horses. However, cases are occasionally recorded when larvae are found in humans - in the eyes or under the skin.
The larva can penetrate into any part human body: arms, legs, chest, head. However, most often she chooses legs, back and armpits. Sometimes the larvae settle in the eyes and nose.
After some time, the area of the skin becomes inflamed, sore, swelling of a bluish or reddish tint appears. An abscess is formed, which after a while opens up. Due to this, a hole is left in the skin, providing the larva with air flow. When the abscess opens, pus comes out of the wound.
Gadfly larvae in the human body cause a deterioration in well-being: vomiting, dizziness, muscle pain and fever appear. At the site of the focus of inflammation, movement under the skin can be felt.
Important! Not detected in time, the larvae are able to penetrate the vitreous body or the anterior chamber of the eyeball, and this is fraught with partial or complete loss of vision.
If it gets into the nose, a headache develops, the sense of smell worsens, a pain sensation appears in the nose, swelling of the nose and mucous membranes is formed. The larvae can even go out through the nostrils.
What harm do they do to the body?
Possible complications - the development of a secondary infection.
How is a larval infestation treated?
The disease caused by the larvae of the human gadfly has a name - dermotobiasis.
Diagnostics
To diagnose the disease, a blood test is used to determine the amount of antibodies. The patient will be asked if he has been to places where the disease is spread. A visual inspection is also used, during which a purulent abscess with a hole is found on the skin. The doctor examines the focus of inflammation with a magnifying glass.
Medical treatment
Extraction of the larva
After successful completion of the procedure, an antiseptic bandage is applied to the damaged area of the skin.
When traveling to countries with a tropical climate, you should take precautions: wear protective clothing against insect bites, use repellents. If the bite blood-sucking insect could not be avoided, it is necessary to carefully treat the wound with a disinfectant, monitor its condition and consult a doctor at the slightest deviation from the norm.
