Adult mosquitos are used in a laboratory test to detect the West Nile virus. (Dave Chidley/Canadian Press)

A second case of human infection with the West Nile virus has been confirmed in B.C.'s Okanagan, but a regional medical health officer says that comes as no surprise.

Dr. Paul Hasselback said preliminary tests were positive, and that both infected individuals were bitten by mosquitoes at the same time and live in the same house in the Okanagan.

Now that the virus has migrated to B.C., Hasselback said, prevention becomes important.

"The key is to avoid getting bitten by them [mosquitoes]," Hasselback said.

The first confirmed human case of West Nile virus contracted from B.C. mosquitoes was confirmed in late August. The Kelowna resident said it was contracted in the south Okanagan

"We now have nine mosquito traps that have tested at various different points, which have also demonstrated the virus, and that is a reminder to all of us that at this time mosquitoes of a particular species in the south Okanagan are capable of transmitting the West Nile virus," he said.

The risk of catching the virus this season is dropping and will end once the frost hits and the mosquitoes hibernate or die off, Hasselback said, but he cautioned the virus will return in the spring.

"Next year we'll have more mosquitoes. What we need to be doing is getting used to the concept that West Nile virus is here and likely to stay here," he said.