How do mosquitoes transmit diseases in Toronto?

mosquito

The statistics of deaths arising from shark attacks and snake bites is nothing compared to that of mosquitoes. Little wonder the saying, “Mosquitoes are no joke.” They carry pathogens of illnesses like Malaria, West Virus, Yellow fever etc., and carry them efficiently. (Could there be a deadlier organism?) From theFemale anopheles, to Culexand even Aedes, mosquitoes are outrageous!

Their persistence and infestation in Toronto isn’t unknown either. Yearly, many Canadians develop life-threatening illnesses traced to mosquito infections. We know already that it is less expensive to prevent the transmission of diseases caused by mosquitoes, than it is to treat such diseases. To even think that some of these diseases lack vaccines or medications that will help in treating them?

Recall the 14 death cases recorded in Canada in year 2002, as a result of the spread of West Nile virus- a virus transmitted by Culexmosquitoes.

The event posed great alarm that year and this could continue, if there is no lucid explanation of the transmission of diseases by mosquitoes in Toronto. And so, if we will protect ourselves from being infected by mosquitoes, we should understand just exactly how they transmit diseases.

Transmission of diseases by mosquitoes

Mosquito-borne infections/diseases are illnesses that are transmitted to humans from the bite of a mosquito.  The most common of such disease in Canada is the West Nile virus. Others include Western, Eastern, and St. Louis Equine Encephalitis viruses.

Taking the West Nile virus as an example, the virus naturally cycles between Culexmosquitoes and birds. The bloodstream of infected birds contains a high degree of the virus (West Nile). Mosquitoes then become infected by feeding on these birds.

It is known that the primary mode of feeding in mosquitoes is by biting- they suck in the blood of the infected birds and in turn, become infected. In about two weeks, infected mosquitoes spread the disease even more. They feed on other birds and hence, infect them with the virus.

What are the chances of contracting a disease from a mosquito?

Since mosquitoes also bite humans and other mammals, mosquitoes infected with the West Nile pass it on to humans, horses etc. This they do, through bites. Mammals (man, horses etc), are however dead-end hosts and as such, cannot pass the virus to other mosquitoes (even when they bite them). This is because mammals do not retain high levels of the virus in the bloodstream.

As explained, mosquito-borne infections are spread basically through the bite of infected mosquitoes. Not every mosquito is capable of infecting mammals. Only certain types carry and spread infections.

Although, most mosquito-borne infections are only passed by mosquito bites, there is also a (very) low risk of getting some diseases (like the West Nile virus), through blood transfusions or organ transplants. To reduce this risk, is the need to test blood donations for the virus.

Having understood that mosquitoes transmit diseases in Toronto and elsewhere, primarily by biting, there is no better way to prevent the risk of infection than to stay indoors in times when mosquitoes are most active. This way, you avoid their bites entirely.