Lockdown is easing and mosquito season is upon us and so people are concerned. Considering that these bloodsuckers are known to transmit diseases, people are asking if mosquitoes carry the coronavirus? And if so, can they transmit it to humans and infect a person with COVID-19?
In short the answer is: it’s unlikely. Official guidance from the World Health Organisation (WHO) says there’s no information or evidence to suggest that the new coronavirus could be transmitted through mosquito bites.
For starters, the coronavirus is a respiratory virus, and the main mode of transmission is viral droplets released into the air when an infected person coughs or sneezes. For a mosquito to become infected with a virus, it must be present in the blood the mosquito feeds on.
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. Plus, for a virus to pass to a person through a mosquito or other kind of insect bite—such as a tick bite—the virus must be able to replicate inside the mosquito or tick. Neither the new coronavirus nor any other type of coronavirus has been shown to do that.
Furthermore, mosquitoes are very genetically different from humans. This makes it challenging for viruses to have the ability to infect both of us. We have different receptors on the surface of cells and different replication machinery inside our cells.
Relatively few human viruses have the ability to infect both humans and mosquitoes. “The vast majority of human viruses (such as influenza, HIV, and herpes) have been infecting humans for a very very long time, and even though many of these end up in our blood, they are still unable to infect mosquitoes. Conversely, there are many mosquito viruses that are unable to infect humans, or any mammals. There are no known coronaviruses that can infect mosquitoes.
Viruses that can be spread to humans by mosquitoes include West Nile virus, the virus that causes dengue fever, and chikungunya virus, which all circulate in the blood of infected people.
So it’s pretty clear that COVID-19 is the last thing you should be worrying about if a mosquito has been feasting on your leg. Keep swatting them away, though. Due to the heavy focus on COVID-19, many people may forget that disease threats may already be buzzing right outside their window.