Arbovirus surveillance in the North American Arctic: California serogroup viruses activity in Aedes mosquitoes (Culicidae: Diptera) and first detection in Simulioidae flies (Diptera)

Due to global warming, the polar climate that was once able to limit the spread of viruses transmitted by arthropod vectors (arboviruses) can no longer fulfill its role. Emerging arboviruses that can affect human health are likely to pose significant consequences for Arctic communities where access to health resources is limited.  Although the scientific community is increasingly interested in many facets of Arctic research, little is known about arboviruses in this part of the world. Therefore, in 2018, we established an arbovirus surveillance program in 7 sites across the North American Arctic to detect the presence of California serogroup viruses in biting flies. Those arboviruses are vastly spread in North American and are known to cause a wide range of symptoms, from mild febrile illness to fatal encephalitis.  Insects were captured twice daily for a 7-day period in July, using a standardised protocol consisting of 100 figure-eight movements with a sweep net. Flies were separated by genus (mosquitoes) and by superfamily (other flies), and then grouped into pools of 75 by geographical locations.  Here, we report the results from the second year of surveillance, including the detection of California Serogroup viral RNA in Aedes mosquitoes captured predominantly in Kuujjuaq (northern Québec, Canada). We also report, for the first time in North America, the presence California Serogroup viral RNA in Simulioidae flies (Diptera). These results highlight the importance of long-term arbovirus surveillance to monitor the changing impact of vector-borne disease on human and animal health in the Arctic.