Mosquitoes: Infection, Transmission & Diseases

Mosquitoes are common all over the world. Most people have had some experience with the insects. Most of the time they leave only swellings and itching, but they can also transmit pathogens. That is why greater caution is required, especially in tropical regions.

What are mosquitoes?

Mosquitoes belong to the bipedal family. In total, there are about 3500 different species of mosquitoes. In Europe, about 104 species are common. Mosquitoes remind of parasites, because they need the blood for their survival. However, it is usually not their goal to infect humans with diseases. It is the mosquitoes themselves that are colonized by various microorganisms and sometimes become carriers. The mosquitoes have specific tools at their disposal to pierce the skin of their host and ingest blood. It is exclusively females that require human blood. Males use plants for food. For females, however, blood is essential because they need the proteins it contains. In this way, successful production of eggs, and therefore offspring, is ensured.

Occurrence, distribution and characteristics

The blood serves less for the supply of the mosquito itself. This takes, just like their male conspecific, for further supply nectar and other sugary plant juices. Also, not all of the 3500 mosquitoes are dependent on humans. Some different populations have specialized partly on hosts. For this reason, only some species are usually considered as carriers of certain diseases, such as malaria or dengue fever. Mosquitoes have been on earth for a very long time. The oldest fossil on which a mosquito can be seen has an age of about 79 million years. A related species, similar in many characteristics to our present mosquito, existed 90 to 100 million years ago. Mosquitoes colonize almost all regions of the planet. The only exceptions are polar regions and deserts, whose living conditions are not designed for the survival of mosquitoes. The insects can usually be found in particularly high numbers in the immediate vicinity of bodies of water. The size of the body of water is irrelevant. Swampy areas are particularly suitable for the development of mosquitoes. Accordingly, tundra and taiga, for example, are optimal breeding grounds for mosquitoes. The size and external appearance of mosquitoes depend largely on the species. However, the insects do not grow larger than 1.5 centimeters. Their two wings sometimes have scales, and legs and proboscis are about the same length. The legs and trunk of the mosquito are narrow. In total, such an insect weighs between 2 and 2.5 milligrams. The females are usually slightly larger than the males. In addition, the latter often have denser, bushy antennae. Mosquitoes cover distances at a speed of 1.5 to 2.5 kilometers per hour. At what altitude they fly depends on several parameters. These include the species, the altitude of the location above sea level, weather, air pressure, light conditions, and temperature. Warm, windless weather provides optimal flight conditions for mosquitoes. Mosquitoes develop in different stages. Eggs transform into larvae, from which pupae emerge. After the insect hatches, the mosquito is called an imago. Male mosquitoes usually hatch earlier and die in the fall.

Diseases and ailments

Mosquitoes don’t just leave you itching. Some of them can transmit serious diseases. The risk is particularly high in tropical areas. That is why it is recommended to pay attention to long pants and tops when vacationing at the equator. Ideally, they should be light colors, on which the mosquitoes can be detected more quickly and prevented from biting. Otherwise, there may be serious consequences. For example, an infected mosquito can transmit malaria. Malaria is a disease caused by parasites. The mosquito has become infected with plasmodia and transmits them as soon as it bites a human. The human being is only the intermediate host in the cycle. Ultimately, the parasite prefers to spread in mosquitoes. Nevertheless, the parasites cause numerous symptoms in humans.The microorganisms enter the human liver after the sting and multiply here. After some time, they disperse in the blood and infect the red blood cells. As soon as these burst due to the strong multiplication, the parasites look for new blood cells. In particular, episodes of fever occur. Other symptoms depend primarily on the specific manifestation of malaria. If left untreated, the disease can lead to death. Therefore, it is advisable to be examined directly at the first signs. A blood test usually provides information about the state of health. Another disease caused by mosquitoes is dengue fever. Every year, about 50 million people contract the disease. The pathogens are transmitted by the Aedes mosquito in tropical areas. There are no uniform symptoms. Instead, the disease manifests itself in very different ways, for example as a skin rash, itching, headaches and aching limbs, or flu. The symptoms persist for about a week. Usually, the disease does not leave any permanent damage.