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Flies can transmit diseases because they are in constant contact with decomposing materials, such as feces or dirt, carrying bacteria and parasites capable of causing some diseases, such as intestinal infection, myiasis, loiasis and sleeping sickness, for example.
Some diseases transmitted by flies are not so common in Brazil, since they are more easily found in African countries, however intestinal infection, for example, can be caused by houseflies and, therefore, it is important avoid eating foods that may have come into contact with flies, as they can carry some microorganisms in your body.
In the presence of signs and symptoms indicative of disease caused by flies, it is important that the doctor is consulted so that the evaluation can be carried out and the most appropriate treatment can be initiated.
The main diseases transmitted by flies are:
Myiasis is a disease in which there is an infestation of fly larvae on the skin, which can occur in any part of the body, such as the foot, ear, mouth and nose, for example, resulting in the appearance of open wounds with pus and bad smell. These wounds arise because fly larvae feed on living or dead tissue.
Depending on the species of fly responsible for myiasis, the larva may remain more superficially on the skin, or penetrate, resulting in more serious infections that must be treated immediately to prevent complications. Learn more about human myiasis.
What to do: It is essential that the doctor is consulted as soon as the first signs of myiasis appear so that the most appropriate treatment can be started. In most cases, the larvae are collected, which can cause pain and discomfort, in addition to the use of antimicrobial drugs in order to prevent secondary infections.
In more severe cases, in which the larva managed to penetrate the skin, surgery to remove the larva may be indicated and, in some cases, surgery to reconstitute the tissue.
2. Sleeping sickness
Sleeping sickness, also called human African trypanosomiasis, is a disease caused by the bite of the tsetse fly infected by the parasite Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense, resulting in the development of symptoms a few weeks after the bite of the fly, such as red spots on the skin that can later turn into sores, headache, fever, swelling and excessive sleep.
Excessive sleep is usually indicative of more severe cases of trypanosomiasis, because the symptoms of the earlier stages of the disease are common to other diseases, which makes diagnosis and initiation of treatment difficult. In this way, as the parasite is not eliminated, there is a greater chance of the nervous system being affected, resulting in sleep disturbances, mental confusion and changes in behavior.Check out other symptoms of sleeping sickness.
What to do: When sleeping sickness is suspected, it is important that the doctor is consulted so that tests are carried out to confirm the Trypanosoma brucei infection. After the diagnosis, the doctor may indicate the use of some medicines to control the symptoms and favor the elimination of the parasite. It is essential that the person is monitored regularly, and it is important that tests are carried out to verify the effectiveness of the treatment and ensure that the disease does not happen again.
Loiasis, popularly known as bug or eye worm, is an infectious disease caused by the Loa loa larva, which is deposited on the skin by the mango fly, widely found in Africa. Thus, after deposition, the larvae start to feed on the tissue and go to the main site of infection, which corresponds to the eyes, causing symptoms such as pain, irritation and redness of the eyes, which can also be seen in the eyeball.
What to do: It is important that the ophthalmologist is consulted so that the best treatment can be started, which usually involves the use of anti-inflammatory, antiparasitic and/or steroids. In the most serious cases, in which it is possible to notice the presence of the larva in the eye, a small surgical procedure may be indicated for its removal. See more details of treatment for loiasis.
Onchocerciasis, also popularly known as night blindness, is caused by the bite of a black fly infected by the parasite Onchocerca volvulus, and this fly can often be found near rivers. The main complication of onchocerciasis is blindness, which happens when the microfilariae of this parasite reach the eyes, affecting the cornea and causing local hemorrhage, keratitis and atrophy of the iris. Learn more about symptoms of onchocerciasis.
What to do: It is recommended that the doctor be consulted so that an assessment of symptoms and visual capacity is carried out and, thus, treatment is indicated, which is usually made with the anti-parasitic Ivermectin.However, this drug has no action on adult larvae and, therefore, surgery may be necessary to remove the adult larvae of the parasite.
5. Intestinal infection
Flies have a predilection for decomposing food and, therefore, can come into contact with various microorganisms, including bacteria and parasites responsible for gastroenteritis, for example. Thus, when the fly comes into contact with these infectious agents, it can transport it to a "clean" food, so that when it is consumed it can cause infection in people, depending on the amount of microorganisms present there.
What to do: To avoid this type of infection, it is important to prevent flies from coming into contact with food, in addition to not eating the food that has entered contact with the fly. If you have consumed food potentially contaminated by the infected fly and you notice the appearance of symptoms of intestinal infection, it is important to remain at rest, have a he althy and easily digestible diet and drink plenty of fluids throughout the day.
Be careful to avoid flies
Some simple precautions to avoid flies and, consequently, the diseases they transmit are:
- Do not let garbage accumulate inside the house for more than 2 days;
- Wash the bottom of the container where the garbage is placed with bleach or chlorine once a week;
- Use a plate or other utensil to cover the food, avoiding leaving it exposed;
- Avoid eating food that has been in direct contact with flies;
- Putting mosquito nets on windows;
- Use a mosquito net to sleep, especially for babies;
- Wear long clothes in places where there are a lot of flies.
However, if flies manage to grow indoors even following these tips, there are ways to eliminate them, such as using insecticides, traps or sprays.