Vancouver Coastal Health and the BC Centre for Disease Control with additional partners plan to conduct a small-scale mosquito surveillance pilot project in the Sea to Sky region to better understand the local mosquito population and the viruses they carry.
The province is responding to a cluster of cases involving the Snowshoe Hare virus and Jamestown Canyon virus where Vancouver Coastal concluded all patients who contracted these viruses did so within the Sea to Sky corridor, according to a July 18 media release from the health authority.
Four cases of the California serogroup virus, which includes Snowshoe Hare and Jamestown Canyon viruses, were reported in the region in late 2024. The health authority said the cases presented with swelling of the brain.
These viruses, within the California serogroup, don't typically cause symptoms, and if they do, it's usually minor in nature and something that the individual can recover from without the need for treatment, the release said. However, the release added that the number and severity of the cases in late 2024 triggered an investigation by the health authority.
The province is warning residents and travellers to the Sea to Sky that if they are suffering from any sort of neurological issue to seek a doctor. It is recommended to take any preventative measures possible against mosquito bites while going through the area from now until fall, the release said.
鈥淲e鈥檙e also undertaking the mosquito surveillance project to learn more about the risk to the public,鈥� Dr. Moliehi Khaketla of Vancouver Coastal Health said.
The study will gather data, assess risk and inform the public on precautions against mosquito-borne illness in the Sea to Sky area.
Although the Snowshoe Hare virus and Jamestown Canyon virus have been identified provincially and nationally, it is rare for them to cause human illness and Vancouver Coastal Health estimates this period may be extended due to increasingly warmer temperatures habitable for mosquitoes.
A survey from around Canada suspected the pair of viruses to be linked to an under-recognized cause of meningitis and encephalitis. The survey found between one and 42 per cent of the country's population have shown evidence of prior infection.
Very rarely do symptoms like meningitis and encephalitis occur 鈥� but where hospitalization is required, is with neurological symptoms such as, but not limited to, confusion, seizures, and/or severe headaches with fever. There is also no human vaccine available to prevent acquiring California serogroup viruses.
Vancouver Coastal Health recommends using mosquito repellent, wearing protective clothing or installing screens when able. People should also be aware of potential mosquito breeding sites, which could be anything that can hold stagnant water, such as saucers under flower pots, bird baths, rain gutters and even backyard pools.
