A Hamilton man and two horses have been infected with a rare and potentially deadly mosquito-borne virus, health officials say.
Late last month, Hamilton Public Health Services said it received laboratory confirmation of a human case of eastern equine encephalitis (EEE).
EEE is transmitted through a virus typically found in wild birds, however, humans and/or horses bitten by an infected mosquito can become infected with EEE. Symptoms in people usually appear three to 10 days after a bite, and most people won’t have any symptoms, officials said.
Others may experience mild flu-like illness with fever, headache and fatigue, but severe cases of EEE involve inflammation of the brain, which starts with a sudden headache, high fever, chills and vomiting.
The man who was infected had no known history of travel, officials said. Two horses have also been infected in the region this year, including one on Aug. 18, they added.
“While the risk of being infected with Eastern Equine Encephalitis (EEE) virus is low, residents should take precautions to avoid illness spread by mosquitoes,” Dr. Bart Harvey, associate medical officer of health, said in an Aug. 28 statement.
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“Employing simple preventive measures such as using insect repellent containing DEET or Icaridin, covering up, and removing standing water on your property to prevent mosquito breeding will reduce your risk while you enjoy the outdoors. The risk of these infections will drop once there is a heavy frost that reduces the number of mosquitoes.”
What is the deadly ‘Triple E’ mosquito virus spreading through northeastern U.S.?
Last September, an Ottawa resident died after contracting EEE. The fatality rate among those severely infected is 30 per cent, the Public Health Agency of Canada states on its website.
The virus is found in the eastern part of North America and is largely a seasonal virus, with peaks in summer months, PHAC said. However, over the past two decades, the number and frequency of human cases have increased, culminating in one of the largest EEE outbreaks in the northeastern U.S. in 2019.
PHAC said the outbreak involved 38 human cases nationally, with 23 occurring in the northeast.
It added that the factors causing the increasing trend are complex and not clear, but “it is suspected to be related to environmental changes that support higher mosquito densities and more intense virus amplification in transmission cycles.”
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