Pathfinder
Editor, Senior Moderator
Canadian mosquito spread of Zika untested
CBC News Posted: Jan 29, 2016 8:32 PM ET Last Updated: Jan 29, 2016 8:44 PM ET
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Hunter is interested in the role insects play in the spread of disease. She's applied to the federal government to study Zika virus at a Level 3 lab.
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We keep reporting that Canadian mosquitoes aren't likely to be a concern.
We don't actually have Aedes aegypti here in Canada. It is in the southern States, it's made of good incursion in southern states but not here. It overwinters in the egg stage, and our climate is just too cold, so they die out.
However there is a second species we are concerned about. It's the one called Aedes albopictus, which is the Asian tiger mosquito. It is also an invasive species, also found in the southern States, and it's moving its way northwards. In fact, this is one of the mosquitoes that's being transported all over the world and becoming an invasive species everywhere it's going, and it can tolerate cooler temperatures. So the concern is that it may in the future be able to establish in Canada.
It's in southern New York state, in New Jersey, Pennsylvania. It's definitely moving northwards, and we can potentially have it here in the future.
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Can we get into the specifics now about why our homegrown mosquitoes can't carry these viruses?
I would love to be able to say that our normal Canadian mosquitoes can't carry the virus but honestly we just don't know. There have been no transmissions studies done in Canada yet to see whether or not Zika virus can be transmitted by local mosquitoes. We know that we do have several species that we're concerned about and the Public Health Agency of Canada is planning on testing those species to see if they are competent vectors. And here at Brock we also have a containment level three lab where we can also test species. We're just waiting to get the permits to be allowed to work with Zika.
We're actually not accurate when we say with confidence that these Canadian mosquitoes can't carry it. Is that right?
That is actually a true statement. We do not know whether our species can transmit or not because the studies just haven't been done.
The species that are in the genus Culex are able to transmit many arboviruses that are related, actually, to Zika virus. However, they have a different life cycle. Culex mosquitoes generally transmit viruses that have a bird as an intermediate host. The thing with Zika virus and also, incidentally with dengue and chikungunya, those are diseases or viruses that can be transmitted from a human to a mosquito to a human, so there's no need for an intermediate host.
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What studies do you want to do and what questions you want to answer in terms of the ability of certain species to carry Zika in Canada?
We would want to know whether or not species that are actually found here are capable of picking up the virus and then replicating it inside their bodies and have that virus move to their salivary glands so that when they then feed on their next host, they can spit it into their next host. So, it's called a competency study to look at whether or not our home-grown mosquitoes can transmit.
...
http://www.cbc.ca/news/health/zika-mosquitoes-1.3426603
CBC News Posted: Jan 29, 2016 8:32 PM ET Last Updated: Jan 29, 2016 8:44 PM ET
...
Hunter is interested in the role insects play in the spread of disease. She's applied to the federal government to study Zika virus at a Level 3 lab.
...
We keep reporting that Canadian mosquitoes aren't likely to be a concern.
We don't actually have Aedes aegypti here in Canada. It is in the southern States, it's made of good incursion in southern states but not here. It overwinters in the egg stage, and our climate is just too cold, so they die out.
However there is a second species we are concerned about. It's the one called Aedes albopictus, which is the Asian tiger mosquito. It is also an invasive species, also found in the southern States, and it's moving its way northwards. In fact, this is one of the mosquitoes that's being transported all over the world and becoming an invasive species everywhere it's going, and it can tolerate cooler temperatures. So the concern is that it may in the future be able to establish in Canada.
It's in southern New York state, in New Jersey, Pennsylvania. It's definitely moving northwards, and we can potentially have it here in the future.
...
Can we get into the specifics now about why our homegrown mosquitoes can't carry these viruses?
I would love to be able to say that our normal Canadian mosquitoes can't carry the virus but honestly we just don't know. There have been no transmissions studies done in Canada yet to see whether or not Zika virus can be transmitted by local mosquitoes. We know that we do have several species that we're concerned about and the Public Health Agency of Canada is planning on testing those species to see if they are competent vectors. And here at Brock we also have a containment level three lab where we can also test species. We're just waiting to get the permits to be allowed to work with Zika.
We're actually not accurate when we say with confidence that these Canadian mosquitoes can't carry it. Is that right?
That is actually a true statement. We do not know whether our species can transmit or not because the studies just haven't been done.
The species that are in the genus Culex are able to transmit many arboviruses that are related, actually, to Zika virus. However, they have a different life cycle. Culex mosquitoes generally transmit viruses that have a bird as an intermediate host. The thing with Zika virus and also, incidentally with dengue and chikungunya, those are diseases or viruses that can be transmitted from a human to a mosquito to a human, so there's no need for an intermediate host.
...
What studies do you want to do and what questions you want to answer in terms of the ability of certain species to carry Zika in Canada?
We would want to know whether or not species that are actually found here are capable of picking up the virus and then replicating it inside their bodies and have that virus move to their salivary glands so that when they then feed on their next host, they can spit it into their next host. So, it's called a competency study to look at whether or not our home-grown mosquitoes can transmit.
...
http://www.cbc.ca/news/health/zika-mosquitoes-1.3426603
