Signs of WNV vary by depending on the species affected. Some birds carry the virus, remaining asymptomatic while some species are highly susceptible. Clinical signs can range from no reaction to the virus to mortality, especially in corvids (crows, ravens and magpies). Finding dead ravens, crows, magpies, and birds of prey may indicate WNV is present in an area.
The bear eats the fish, fish eats the mosquito, and mosquito stings the bear. Instead of just standing there, it becomes a tag game. • The “winners” of the farkle chase members of the other team.
WNV has also affected sage grouse in some areas of Idaho and the intermountain west. Birds usually do not show any clinical signs when infected with WNV. Chickens can be infected with WNV and not become sick. However, natural disease due to the virus has been reported in domestic geese, ducks, pigeons and chickens. In humans, 80% of WNV infections remain asymptomatic reactions. In the 20% of people who show symptoms of WNV infection, most present with the relatively mild fever and approximately 1% develop more serious nervous system problems and some may die.
Avoiding mosquito bites is the most important aspect of protection for humans to avoid WNV. Humans should wear mosquito repellent containing DEET in accordance with the label, wear long-sleeved shirts and long pants, particularly during dusk and dawn when mosquitoes are most active, repair broken screens in houses, and reduce standing water around homes to reduce mosquito breeding habitat. Horses are susceptible to West Nile virus, but a vaccine is available and should be administered.