Lately, a lot of health topics included the Zika virus and before that the dengue fever, both carried and spread by mosquitoes. Here is the reason why mosquitoes spread so many diseases.
According to Doctor Amesh Adalja, the reason mosquitoes carry so many diseases is because of their vampire tendencies. The mosquitoes drink blood and when they do it, they ingest the microbes found in the blood and later pass them on when they feed on another victim. What also helps them spread the disease is their ability to fly long distances. The female mosquitoes are the most dangerous, since they ingest the blood needed for their eggs.
Contrary to popular opinion, not all the mosquitoes spread diseases. According to an entomologist from CDC called Janet McAllister, only the mosquitoes that live close to humans are dangerous, since they prefer the human blood to the animal one. They become very good at taking blood and most of them do it while people sleep. The ones that bite during the day have some chemicals in their saliva that allows the biting to go unnoticed by the humans, until the itching starts.
Some diseases are carried by mosquitoes in areas which have never dealt with those diseases before, because of the climate changes that occur. As the temperatures rose in many places, the mosquitoes expanded their areas as well. Americans are extremely lucky because even though climate changes occurred, the winters are still too cold for the mosquitoes, that die during the colder season.
The mosquito borne diseases are caused by viruses or bacteria that are later transmitted by mosquitoes. Mosquitoes are able to transmit diseases without getting infected. The diseases spread by mosquitoes include West Nile virus, dengue, malaria, yellow fever and Zika fever. Every year, 700 million people die of a mosquito born disease, of which 1 million people end up dying.
Mosquitoes manage to stay healthy despite the viruses they carry because their immune system renders inert the virus. Other viruses change the behavior of the mosquitoes, once they have it in their bodies. When a mosquito carries the malaria virus for example, the mosquito feels the need to feed more often, and thus the virus is spread more easily.
When a mosquito bites a human, it injects saliva into the human blood and if the saliva is infected, so will the human. In order to control the diseases transmitted by mosquitoes, people tried to kill the mosquitoes, to isolate the infected people and to reduce their reproduction.
The reason why mosquitoes spread so many diseases is mainly because they like to feed on blood, especially on human blood and they can also travel long distances.
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