Monsoon season is upon us. And with it will come scourge of mosquitoes. As we know well enough that these bloodsuckers are disease spreaders, understandably many people would be concerned if mosquitoes carry coronavirus, and if so, can they infect humans with COVID-19?
You may put your worries to rest, mosquitoes can not spread coronavirus. The official guidance from the World Health Organisation (WHO) has made it clear that there's no information or evidence that mosquito bites can transmit coronavirus.
Mosquitoes can't spread coronavirus
"Mosquitoes cannot transmit the disease," said Tarik Jasarevic, a WHO spokesman, because the virus does not widely circulate in the blood and is more prevalent in lungs and the respiratory tract, reports ProPublica.
A similar observation has come out from the U.S. Centers for Disease Control and Prevention which said, it "has no data to suggest" that the coronavirus is spread by mosquitoes or ticks.
COVID-19 is a respiratory disease
To begin with, COVID 19 is a respiratory disease and not a blood disease. It spreads through the droplets that come out when an infected person coughs, sneezes, or talks.
If a mosquito bites a COVID 19 infected person then the mosquito itself won't get infected. The reason being that the SARS-CoV-2 is generally not present in the blood but in the respiratory tracts.
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"SARS-CoV2 (the virus that causes COVID-19) is a respiratory virus that is almost exclusively contained within the lungs and respiratory tract of infected people, and rarely gets into the blood," says Emily Gallichotte, PhD, a postdoctoral researcher in the department of microbiology, immunology, and pathology at Colorado State University, in an interview to Health.
Mosquitoes genetically different from humans
In a different scenario, if somehow, the virus takes in the droplets of an infected person either by licking a contaminated surface, or suck up blood that contains a virus, there is still no chance of the mosquito getting infected.
In the above case, if the coronavirus manages to reach inside the gut of the mosquito, it would still be challenging for the virus to survive there. Mosquitoes are genetically very different from us and thus virus does not replicate the same way as they do in humans. "We have different receptors on the surface of cells and different replication machinery inside our cells," says Gallichotte.
None of the coronaviruses including SARS and MERS has been shown to do that.
For a virus to infect any other person it must replicate inside the mosquito-or tick. If the mosquito isn't infected it can't transmit it to any other person.
Mosquitoes can transmit other viruses
There are several mosquito-borne viral diseases that can cause infection in humans. Diseases like dengue, yellow fever, chikungunya, Zika, West Nile virus etc are all viral disease spread by mosquitoes.
At the same time, there are many other viruses which mosquitoes can't transmit, like HIV, Ebola and Coronavirus.
In Nile and dengue cases, the virus is present in the blood of an infected person. And when a mosquito bites an infected person, it takes in enough viral load with the blood that is sufficient to infect the mosquito itself. And in a week time, the mosquito is able to infect all the person he bites.
"West Nile virus is able to infect a mosquito to the point where the virus load is abundant in the salivary glands," Melissa Doyle, scientific program manager at the San Gabriel Valley Mosquito and Vector Control District (SGVMVCD), explains to Health. "When the mosquito bites a person, the virus is able to travel from the salivary glands into the human body."
Complications come up when COVID-19 is combined with other diseases
This makes clear that mosquitoes do not spread coronavirus and you do not need to worry if it bit you. But the other diseases that they can transmit is surely a cause of concern, especially in these times.
Recognising that mosquito-borne viral diseases are sometimes very severe, it can cause complications if combined with COVID-19 cases. If a person is already COVID 19 positive or first gets infected with mosquito-borne diseases and then contract COVID 19, his situation could deteriorate quite fast if medical aid is not provided on time.
It is therefore recommended to take precautions, follow healthy coronavirus protocols and take strong measures to reduce the number of mosquitoes low to protect yourself from COVID-19 and other diseases.