West Nile virus has been detected in mosquitoes, birds and horses in eastern Oregon, and the Oregon Department of Human Services (DHS) is encouraging residents to take steps to protect themselves and their pets.
There have been no human cases reported in Oregon this year, according to Emilio DeBess, D.V.M., State public health veterinarian.
"The risk of an individual contracting West Nile virus is low, but we do encourage people to take appropriate precautions to protect themselves against mosquito bites," said Dr. DeBess.
The Oregon State University Veterinary Diagnostic Laboratory in July and early August detected West Nile virus in mosquitoes in Baker, Malheur, Morrow and Umatilla counties. The virus was also detected in five birds and two horses in those counties, as well as Union County. Most of the mosquito activity is concentrated in Morrow and Umatilla counties, with 78 positive mosquito pools in Morrow and 24 in Umatilla. Baker County had six pools where the virus was active, and Malheur County had five.
A higher number of mosquito pools with the virus could lead to human and animal infection, according to DHS.
Most people who become infected with West Nile virus do not become sick. Some may develop mild flu-like symptoms such as fever, headache, body aches and occasionally swollen lymph glands or a rash. In some cases, the central nervous system is affected, which can lead to nervous system disorders such as meningitis or encephalitis.