The West Nile virus is, in fact, moving west, but only when ravens, jays or magpies start turning up dead around town do Missoulians need to turn into worry-warts.
“You really need lots of prey and lots of infected birds to get this thing going and get transmissions in humans,” says Jim Carlson, director of environmental health with the city.
During a board meeting of the Missoula City/County Health Department last week, Carlson presented information showing that West Nile virus reached the edge of the Rocky Mountain Front last year, but didn’t quite reach Missoula. Because the disease infects birds, the tell-tale signs that the virus has come knocking are dead resident birds.
“I happened to see a starling laying out in the field the other day,” said a man in the audience: Should he call Fish, Wildlife and Parks?
The answer, says Carlson, is yes. FWP can then test for the presence of the virus—but FWP must be alerted soon after the bird’s death.
It’s mosquitoes that pick up the virus from birds and transmit it to humans. Humans can contract the virus to varying degrees, including imperceptible symptoms, when the mosquito digs its proboscis into human flesh and secretes a chemical that keeps blood from coagulating.
Carlson’s advice for the problem months, July and August, is to slather on the bug repellent. If and when the virus comes to town, it’s folks 50 and older who are most susceptible to the harsher fever-like symptoms. To create an unfriendly welcome for the virus, Carlson asks citizens to change the water in their birdbaths every few days and to keep pond pumps pumping. The slightest ripple in the water disturbs mosquito eggs.
Great Falls plans to spray within city limits, and a small patch near Lolo may see spray as well. Missoula, says Carlson, has no current plans to spray.