More West Nile Virus Detected; 10,240 Acres to Be Sprayed Thursday


Public Health officials are concerned about widespread West Nile Virus activity throughout the area and are urging residents of all ages to take the necessary steps to reduce their exposure to mosquitoes.

The North Morrow Vector Control District is reporting that West Nile Virus has been detected in 47 mosquito samples this year. The Oregon State Veterinary Diagnostic Laboratory reported on Monday that 22 additional samples from mosquitoes collected last week have tested positive. The samples were from areas in and around Irrigon and now Boardman. The West Umatilla Mosquito Control District has also reported four positive mosquito samples this year. The virus was initially detected on July 8 in both districts and has become more widespread since that time.

People are encouraged to take appropriate precautions to protect themselves against mosquito bites. Most people who become infected with West Nile Virus do not become ill. Some may develop mild flu-like symptoms such as fever, headache, body aches, and occasionally swollen lymph glands or a rash. In rare cases West Nile may cause encephalitis, or inflammation of the brain. Individuals with severe or unusual headaches should seek medical care as soon as possible. Residents of the district should remain vigilant in protecting themselves from mosquitoes and the diseases that they can carry, such as West Nile Virus.

In response to increased West Nile Virus activity, the district will be conducting targeted aerial mosquito control spraying with a twin engine airplane after sunset on Thursday, weather permitting. The application will be scheduled for the following day if the weather causes a cancellation. A total of 10,240 acres are to be targeted in areas around Umatilla, Irrigon, and Boardman. Further applications will be scheduled as needed to respond to increased vector populations or positive samples as they are found. No areas within city limits are currently scheduled for aerial spraying.

West Nile is primarily a bird disease, and some birds, including magpies, blue jays and crows are especially susceptible. Mosquitoes become infected by feeding on an infected bird and can pass the virus to humans, horses or other hosts when they bite. The public is encouraged to continue to alert district officials when they come across dead birds, so the district can track the spread of the virus.

Because horses are also at risk for West Nile, health officials encourage horse owners to check with their veterinarians for vaccination. Veterinarians can arrange for testing of samples from horses suspected of infection with West Nile Virus.