What does a malaria mosquito look like and how dangerous it is?

Malarial mosquitoes are distributed throughout the globe, but they pose the greatest risk and danger in tropical and subtropical countries. In Russia, the maximum number of cases of infection is recorded in the southern regions, which border on countries included in the global habitat of malaria mosquitoes. Rare cases of transmission of the infectious disease pathogen also occur in other regions of the country.

First of all, it is necessary to indicate how a malaria mosquito differs from a regular one. Many people confuse it with the centipede, a large insect with large wings and long limbs. But the malaria mosquito looks like a regular one. You can recognize it by the following signs:

the length of the limbs is twice the length of the body;
antennae (tentacles near the mouthparts) are almost identical in size to the proboscis;
There are no scales on the abdomen, it is covered with hairs.

Difference from ordinary mosquitoes

A malaria mosquito can be identified by the position of its body on a horizontal surface.
The hind limbs of the insect are significantly longer than the front ones. Because of this, during rest, the body of the malaria mosquito takes on an almost vertical position, while in an ordinary representative of the family it is distinguished by a parallel arrangement. A malaria mosquito bite can lead to various consequences. The degree of complication depends on the type of insect, its habitat, and the body’s susceptibility to infection. Diptera vectors of the disease cause the development of three-day, four-day and tropical fever. It is the latter form of the disease that claims many lives every year. In Russia, only imported cases of tropical fever are found.

Malaria mosquito: the appearance of an insect with a “tarnished reputation”

Malaria mosquito at the moment of defeat

What kind of insect is this that brings trouble to its victim? They belong to the order Diptera. They have an elongated body, reaching a length of up to 10 mm, long legs, and a small head. The wings are covered with scales, and when at rest they are located one above the other.

Malaria mosquitoes have a complex jaw system. It consists of a long trunk and a lower lip - a tube, inside of which there are file-like jaws. Having cut through the skin, the insect pushes its proboscis to the depth of the nearest capillary, from where it sucks blood.

Symptoms of malaria after a mosquito bite in an adult and a child: description

Symptoms of malaria after a mosquito bite
Malaria, or as it is also called swamp fever , is a disease provoked by a parasitic single-celled organism, which, when it enters the human body, begins to very quickly affect internal organs, primarily the liver. After damage to the liver, plasmodia enter the blood and spread throughout the body through the circulatory system. Once this happens, the person begins to feel symptoms of malaria.

IMPORTANT : As practice shows, plasmodia behave more aggressively in the bodies of young children and pregnant women. This is due to the fact that their body cannot fully resist the pathogenic virus and it begins to poison the body as quickly as possible.

Symptoms of malaria in adults and children:

Local manifestation. red blister appears at the site of the bite , which at the first stage causes practically no discomfort. Literally after a couple of hours, the blister thickens, redness appears around it and the itching noticeably intensifies .
If specific therapy is not started at this stage, then after approximately 48 hours (this time period will depend on the body’s resistance), a headache of varying intensity and general weakness of the body . Some people experience a sharp decrease in appetite.
After passing this stage, all unpleasant symptoms suddenly disappear and the person begins to feel quite normal. And at this time, hidden processes begin to occur in his body that disrupt the functioning of internal organs. The asymptomatic period can last 10-45 days. All this time, plasmodia will multiply in the liver to deliver the final blow.
After this period, the person begins to clearly manifest so-called internal symptoms. The body finally notices that there are pathogenic organisms inside it and begins to attack them. Because of this, the patient may have a sharp rise in temperature and may again experience headaches, pain and severe vomiting.
As a rule, after this stage, more unpleasant symptoms begin to appear, which indicate the development of pathologies of the liver, kidneys, heart and circulatory system. A person develops blood in the urine, sudden surges in blood pressure begin, the headache increases many times over, and heart problems appear
. Most often, it is at this stage that liver cells begin to break down and anemia develops.

How to distinguish a regular mosquito from a malarial one

On the left in the photo is a malaria mosquito.

It is extremely difficult to distinguish them from each other by appearance, although experts note a number of features.

The hind legs of malaria mosquitoes are much longer than the front ones.
Body position, as if upside down (raising the back). Ordinary mosquitoes hold their body straight (parallel to the surface).
Malaria mosquitoes have dark spots on their wings.
The whiskers located next to the tubular lip are much shorter in ordinary mosquitoes than in malarial mosquitoes.

A photo of a malaria mosquito gives a complete picture of its difference from a regular one. An interesting feature of malaria mosquitoes is the way they fly up to the victim before biting - performing a kind of ritual dance.

Origin of the species and description

Photo: Malaria mosquito

The malaria mosquito is a dipterous insect, an obligate bloodsucker from the suborder Long-whiskered, which is a carrier of malarial plasmodia, which are considered the most dangerous parasites for humans. The Latin name for this species of arthropod is Anopheles, which translates as harmful, useless. There are 400 varieties of Anopheles, many of them are capable of transmitting malaria, as well as being the main host for a number of other dangerous parasites.

Video: Malaria mosquito

Several fossil varieties are known from Oligocene and Dominican amber deposits. Some historians believe that malaria was the main cause of the fall of the Western Roman Empire in the fifth century. At that time, epidemics broke out in the coastal regions of Italy. The draining of numerous swamps and the construction of new roads resulted in almost constant brutal malaria for the inhabitants of Rome. Hippocrates also described the symptoms of this disease and associated the onset of malaria epidemics with natural conditions.

Interesting fact: Malaria mosquitoes look at the world through the prism of infrared rays, so they are able to find warm-blooded animals and people even in pitch darkness. In search of an object to receive a portion of food - blood, these arthropods can fly over distances of up to 60 kilometers.

“Diet” or why the malaria mosquito is dangerous

The female malaria mosquito is larger than the male

It is the female mosquitoes that feed on blood, while the males drink flower nectar. When born, insects swarm and mate. A fertilized female needs protein to lay eggs, which is why her blood-sucking instinct manifests itself. After laying eggs, for two days, the females are not dangerous; they feed on plant sap. Then, everything repeats all over again - she is fertilized, looks for a victim and lays eggs. In this chain, only the initial stage, after fertilization, is safe for the “victim”. Having bitten a patient with malaria, the mosquito becomes a carrier of the virus of a dangerous disease.

First aid

If you are bitten by a malaria mosquito, you may experience a general or local reaction. At the site of the bite there is inflammation, swelling, and burning pain. After a couple of hours, the initial symptoms disappear.

Often a person experiences a stressful condition. It is based on overexcitation of the body. If a person is hypersensitive to poisons, an allergic reaction may occur. It is marked by reactions such as asthma, urticaria, anaphylactic shock.

If a person has an increased sensitivity to poisons, an allergic reaction may occur in the form of hives

First aid is to wash the wound with alcohol. Something cold should be applied to the fireplace. Next, the bitten person is put to bed and given strong coffee or tea. If vascular or cardiac activity declines, the following is administered:

cordiamine;
caffeine;
adrenaline subcutaneously.

If the patient's condition has not improved, he should be urgently sent to a medical facility. A person is given “Suprastin” or “Diphenhydramine” - 1 tablet (against allergies).

Where there is a threat of being bitten by a malaria mosquito, everything should be done to destroy the source of infection. Mosquitoes can become carriers of anthrax, malaria, and intestinal infections. If there are cases of infection with dangerous diseases, they should be treated by a specialist.

To prevent a bite, use repellents and protective nets, and lubricate the skin with other products. If this is not the case, use gauze or handkerchiefs to cover exposed parts of the body.

Use repellent to prevent being bitten

Regular parsley will help relieve itching. Pluck it, mash it and lubricate the affected area with the juice of the plant. After 20 minutes, there will be nothing left on the body except a reddish spot, reminiscent of a syringe mark.

If you are planning to spend the night outdoors, cover exposed areas of your body with the leaves of burdock or other plants. Bonfires help a lot - flying parasites are afraid of them. It's better to sleep in clothes.

Where do bloodsuckers live - carriers of infections?

The regions where the malaria mosquito lives are marked in red.

Malaria mosquitoes are adapted to life on almost all continents. They are absent only in areas with extremely cold climates. To reproduce, they need bodies of water, on the surface of which they lay eggs. The larva hatches from the egg and remains in the water until it grows into an adult mosquito. However, not every body of water is suitable for their reproduction - insects will not lay eggs in thickets of duckweed and reeds, or in acidic water (wastewater). Mosquitoes choose bodies of water with clean water, algae, which are long and short threads, where it is convenient for the larvae to hide.

Attention! In Russia, several dozen species occupy large territories for their habitat. The common malaria mosquito (Anopheles maculipennis), with 5 twin species, lives in the European part. In the summer, the Republic of Tatarstan and Kazan suffer from them.

The counterpart of the common malaria mosquito - Anopheles messeae, except for the European part, lives beyond the Ural Mountains (the range extends to Mongolia), in the Amur region. The most cold-resistant mosquito that lives in the taiga is Anopheles beklemishevi. It lives where even the malaria pathogen cannot survive.

Mosquito development cycle

The mosquito development cycle consists of 4 stages: eggs, larvae, pupae, and adults. At elevated temperatures and high humidity, parasite eggs develop quickly.

Mosquito eggs

In mosquitoes of the genus Culex, the eggs are glued together and form a “boat” that floats freely in the water. They have an oblong shape and a widened front part with a saucer-shaped rim that allows them to stay on the surface of the water. A characteristic concavity is formed on the surface of the “boat”.

The eggs of the female Anopheles mosquito are located singly, bordered by a concave belt, and have 2 air chambers-floats, which allow them to stay on the surface of the water.

The eggs of the female of the genus Aedes are laid on the bottom of drying up reservoirs, located singly, oval in shape, with a micropyle (small entrance) at one end. After 2 - 14 days, larvae emerge from the eggs.

Rice. 10. Mosquito eggs.

Rice. 11. Eggs and larvae of mosquitoes of the genus Culex.

Larvae

The larvae feed intensively and grow. Before pupation, they increase more than 500 times in volume and more than 8 times in length.

The larvae of Culex and Aedes mosquitoes have a special respiratory tube-siphon, which extends from the penultimate (ninth) abdominal segment. Using a siphon tube, the larvae are held at the surface of the water, positioned perpendicular to the surface of the reservoir. Air enters the siphon through the spiracles. This design helps mosquitoes survive in heavily polluted ponds, ditches, puddles, water vessels and tree hollows.
Anopheles mosquito larvae do not have a siphon tube. A pair of stigmas extending from the penultimate abdominal segment helps them stay parallel to the surface of the water. The larvae survive only in clean water bodies.

The larvae feed through a flow of liquid with microscopic nutrients, which is created by the fans located at the head end. The particle size is limited, which is taken into account when using dust-like pesticides.

The larvae go through 4 stages in their development, separated by molting. After the last molt, the larvae turn into pupae.

Rice. 12. Anopheles mosquito larva (photo on the left) and Culex (photo on the right).

Rice. 13. Anopheles mosquito larva at the surface of a reservoir (picture above) and Culex (picture below).

Rice. 14. The photo shows Anopheles mosquito larvae.

Pupae

During the pupal stage, the insect develops eyes, wings, a proboscis, and legs. Mosquito pupae are mobile.

Culex and Aedes pupae have a cylindrical respiratory siphon. Anopheles pupae have a respiratory siphon in the shape of a “post horn”. This stage ends with the emergence of the winged mosquito, the adult, from the chitinous shell. The development phase in water until the winged form emerges lasts 14 - 30 days. The warmer the water, the faster the winged forms of insects emerge.

Rice. 15. Anopheles pupa (photo on the left) and a Culex pupa (photo on the right).

Rice. 16. Anopheles pupa (picture on the left) and Culex pupa (picture on the right).

Winged Forms

Malaria mosquitoes live near human habitation - in non-residential buildings, near water bodies (breeding sites). During the day, females and males hide in dark corners. At dusk they fly out in search of food, which they find by smell. Insects feed on plant juices, milk, and consume sugar solution and cesspool liquid.
After mating, the female must pump blood, without which the eggs do not develop, for which they attack humans, domestic and wild animals. Females sense clusters of animals at a distance of up to 3 km.
Females suck blood for 0.5 to 2 minutes and suck out more blood than their body weight - up to 3 mg. If this happens in spring and summer, then the female develops eggs. If in the fall, a fat body is formed from the pumped blood, but the eggs do not develop.
After this, they hide in dark places, most often in human housing and premises where livestock are kept. After 2 - 14 days, larvae emerge from the eggs.
Insects overwinter in basements, cellars, storerooms, animal rooms - wherever there are no drafts or light. In winter, mosquitoes are in a state of torpor. The female becomes able to lay eggs already in the middle of winter, but only after sucking blood. Mosquitoes leave their shelters en masse only in the warm season, biting at dawn and dusk.
On warm days, females migrate to a pond where they lay eggs. The first laying of eggs is carried out by overwintered females.
After laying eggs, females fly off in search of food. One female can repeat the egg-laying cycle several times.

Plasmodium malaria is transmitted by mosquitoes of the genus Anopheles. During wintering, the sporozoites in the female's body die. For it to become infected, a new infection from a sick person will be required.

Rice. 17. The winged form of mosquitoes (imago) Anopheles (picture above) and Culex (picture below).

Danger to life from human health

External signs of malaria

Scientists from many disciplines are working to study the diseases that malaria mosquitoes carry. The first most common is malaria. In African countries, it claims more than a million children's lives every year. The main carriers of tropical malaria are females of the species Anopheles gambiae.
The second largest group of diseases caused by a large number of threadworms. Absorbed into the blood of an infected person (with many microscopic worms) through the mouth, the mosquito transfers them to healthy people. As a result, they clog blood vessels, form blood clots, and promote the accumulation of lymph in the arms or legs, which causes them to swell to enormous sizes—elephantiasis develops. The countries of South America, Asia and Africa are “record holders” for the number of deaths from these diseases.
Another group of diseases that are caused by the bite of a malarial mosquito is encephalitis, yellow and tropical fever. This group is characterized by infections with microbes and viruses.

Prevention of malaria

Today, there are extensive travel opportunities, including countries with an increased risk of contracting malaria.
The categories of people most susceptible to the disease often go on trips: children and pregnant women. In this regard, it is advisable to provide travelers with expert advice before departure to increase public awareness. In addition, it is possible to take drugs from the aminoquinoline group on your own if you are planning to travel to countries with a high incidence or if cases of infection have been reported in neighboring areas. Due to frequent cases of counterfeiting of antimalarial drugs, it is recommended to buy them in advance in sufficient quantities and take them with you on the road.

On site you can use:

special protective mosquito nets on windows, doors and around the bed;
sprays based on insecticides for treating clothing, tents, equipment;
sprays based on mosquito repellents directly on exposed skin;
wearing special clothing with long sleeves and trousers, especially during mosquito activity hours [2].

Local authorities are also carrying out measures to destroy mosquito larvae and pupae near water bodies, as well as winged mosquitoes and their breeding sites.
The development of a malaria vaccine is considered a promising direction in the fight against infection. Although it does not eliminate the risk of infection, its use significantly reduces the incidence of illness. The RTS, S vaccine (Mosquirix) is considered the most effective to date, reducing the likelihood of contracting tropical malaria by an average of 50% [3].

Symptoms of bites

It all starts like this - you need to see a doctor immediately

The main symptom of a malaria mosquito bite is fever, even if a small amount of infected parasites has entered the bloodstream. Malaria has 4 forms (tropical, three-day, four-day, oval) with individual characteristics. The disease is divided into three stages, they all have their own symptoms.

During the first latent period there is an acute manifestation of the disease and relapses, headache, chills.
The second stage is characterized by chills, fever, rapid pulse, and convulsions. At the end of the stage, the temperature drops sharply and profuse sweating appears. During attacks, all internal organs suffer and begin to “fail.” After 15 such attacks, the infection gradually subsides.
During the second latent period, relapses may occur if improper treatment is given.

Symptoms of the disease such as headache, fever, chills, and significant sweating are inherent in all forms of malaria, but each has its own characteristics.

Thus, the duration of tropical malaria is from six months to a year. Three-day malaria, in addition to general symptoms, has attacks alternating every other day, which begin in the first half of the day. This disease lasts 2-3 years. The long course of the disease is quartan malaria, accompanied by attacks every two days. Oval is one of the lightest shapes. It may go away within two weeks, but generally lasts 3-4 years. Attacks occur every other day, in the evening.

Treatment of malaria

If a malaria infection is suspected, therapy can be started without confirming the diagnosis if the patient lives in an area with a high risk of infection or has returned from a trip to such a country, as well as if it is impossible to conduct laboratory tests.
Once the diagnosis is confirmed, treatment is aimed at interrupting the life cycle of the parasite in the body, preventing severe complications in the patient and death. The specific therapeutic approach depends on the identified pathogen and stage of infection, as well as the individual characteristics of the patient (chronic or concomitant diseases, immune status, pregnancy in women, lack of response to antimalarial drugs).

To achieve maximum effect, combination therapy is used. The main drugs for malaria include artemisinin derivatives, quinine or its derivative chloroquinine, combined with primaquine. For quartan malaria, primaquine is not prescribed due to the resistance of its causative agent to this drug. Severe tropical malaria can be treated with artesunate, artemether and quinine, and if these are not available, quinidine injection under ECG monitoring. Complications of the disease are treated according to generally accepted regimens.

To prevent relapses and if the pathogen is sensitive, the patient is prescribed long-term use of primaquine after discharge.

Features of character and lifestyle

Photo: Malaria mosquito bite

Malaria mosquitoes are mainly active at night. To search for food, females do not need sunlight at all - they quickly find an object to attack even in the dark, focusing on infrared rays from the victim’s body. Like all mosquitoes, they are very intrusive and do not lag behind for a long time until they do their job.

Anopheles is distinguished by its endurance and great mobility. It is capable of flying for many kilometers without landing or resting. Large flights are mainly made by females in search of food, in which case they are capable of impressive forced marches of tens of kilometers. Males spend almost their entire lives in one place, most often on lawns with a large number of flowering plants.

In countries with a humid tropical climate they are active all year round. In other habitats, individuals born in late summer and surviving hibernate until spring. To do this, they choose secluded places and can even be found in human dwellings. With the first warmth they wake up. The average lifespan of a malaria mosquito is about 50 days.

There are a number of factors that can increase or shorten this period:

air temperature. The lower it is, the longer mosquitoes live;
with a lack of nutrition, insects live longer;
Abrupt climate changes also shorten the life of Anopheles.

It has been noticed that the life cycle of malaria mosquitoes living in forests is much shorter, since it is very difficult for the female to find food in such conditions.

Preventive measures

To avoid contracting malaria, persons who travel to areas with unfavorable epidemiological conditions must take special medications:

Chloroquine. Adults - 14 days before departure, 300 mg once a week. It is necessary to continue taking it for another 4-6 weeks after returning. Children are prescribed at the rate of 5 mg per 1 kg of body weight per week, the course of administration is similar to adults;
Mefloquine. Adults - 7 days before departure and another four weeks after return. Dosage – 250 mg once a week. In children, the dosage depends on weight: from 15 to 19 kg - 0.25 tablets, from 20 to 30 kg - 0.5 tablets, from 31 to 45 kg - 0.75 tablets, over 45 kg - 1 piece.

If there are contraindications to taking special medications, then you can take Doxycyline at a dosage of 100 mg. One dose per day is enough, one or two days before departure and for a month after returning.

You should avoid mosquito bites and use protective equipment - creams, aerosols, mosquito nets.