This 2006 photo made available by the Centers for Disease Control and Prevention shows a female Aedes aegypti mosquito acquiring a blood meal from a human host at the CDC in Atlanta. — Photo distrubuted by CP/AP courtesy of CDC
A mosquito that can potentially carry a deadly virus has been found in St. John’s, according to a news release issued Wednesday by Memorial University.
MUN biology student Kate Bassett collected the mosquito, which has the potential to carry the West Nile virus, inside her St. John’s home. She later confirmed the identification using DNA fingerprinting.
“It’s typical for (mosquitoes) to breed in an urban setting in pots that are left with standing water,” she said.While the virus itself has not been detected, Culex pipiens, one of three species of mosquito responsible for the transmission of West Nile virus and the primary culprit in Eastern North America, has been found in the city.This mosquito species has been collected in the past on the west coast of the island, but it has now been found on the Avalon and within the City of St. John’s.
Bassett also identified a mosquito capable of carrying the West Nile virus while conducting field work in Salmonier Nature Park.
The master of science student researches mosquito-borne viruses in Newfoundland, such as the snowshoe hare virus and the Jamestown Canyon virus. Both infect wildlife, but have also been known to infect humans.
“I catch mosquitoes fairly regularly,” she said. “Quite honestly, the last couple of years relative to my experiences in Nova Scotia, the numbers are quite low.”
Part of Bassett’s research includes collecting mosquitoes, identifying them and sending them to the National Microbiology Lab in Winnipeg, Man., to test them for the presence of viruses.Mosquitoes transmit West Nile mainly between birds. In North America the American robin and crow can be carriers of the illness.
“They feed on migrating birds, so they would typically move across the province, and they move in and out of the province as well,” said Bassett, citing ferry travel as a possible avenue for carrying such mosquitoes from Nova Scotia to the island.Humans who are bitten by a mosquito that has previously fed on an infected bird might develop medical complications related to the virus. This species of mosquito typically looks for roosting birds in the canopies of trees. It breeds in foul and still water, such as that found in clogged rain gutters or inside a discarded tire.
Outbreaks of West Nile disease this summer have been occurring primarily in the United States.
The centre of concern has been Texas, but states bordering on Canada, including Michigan, Minnesota, Idaho and Ohio, have also reported cases.Ontario hardest-hit provinceAccording to Public Health Ontario, West Nile virus activity appears to be surging in that province. It’s reporting that as of Tuesday, there have been 82 confirmed or probable West Nile infections in Ontario this year.Quebec, Alberta, Manitoba and Saskatchewan have also reported human cases, but their numbers are far lower so far.For this year, Bassett said there is minimal risk for contracting the West Nile virus in Newfoundland and Labrador, citing the fact no cases have been confirmed with humans in the Maritimes.
“Typically, you would see sort of a movement from that direction, and where there hasn’t been anything found (in the Maritimes), I think it’s safe to say we are free of it for now.
”She said clusters of crows are monitored by the Department of Natural Resources, as mosquitoes are known to feed on infected crows, adding that clusters can be considered an indicator of the virus’ presence.In order for the virus to spread, specific environmental conditions are required, according to Bassett. While warm temperatures are conducive to the virus replicating in mosquitoes and birds, Bassett said dry weather is not.To date, there have been no fatal cases this year in Canada.Public Health Ontario said that province’s West Nile activity has been reported only in southern Ontario.The United States is also reporting a lot of West Nile activity this year, with 1,590 human cases so far, including 66 deaths.
The U.S. total — based on figures calculated as of Tuesday — is the highest figure to the end of August since West Nile first emerged there in 1999.Bassett said there are approximately 30 species of mosquito in Newfoundland.