West Nile virus, which is spread by mosquitoes, has been detected in mosquitoes at a testing site in Morrow County, according to Oregon Public Health officials.
The mosquitoes, collected on Aug. 19 approximately three miles west of Irrigon on the Umatilla National Wildlife Refuge McCormick Slough, are the second to test positive for the disease in Morrow County in 2024. The previous detection was on July 24.
Health officials are advising people in Morrow County to take precautions against mosquitoes to avoid the risk of infection, including preventing mosquito bites. People who are infected may develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. The incubation period is usually two to 14 days. Rarely, infected individuals may develop neuro-invasive disease (infection of the brain or spinal cord) that can be severe or may cause death. This is especially of concern to people 50 and older, people with immune-compromising conditions, and people with diabetes or high blood pressure. Please contact your health care provider if you experience any of these symptoms and get tested for West Nile virus. Testing is available in most private laboratories.
Communities and individuals living in or spending significant time outdoors, particularly near irrigated land, waterways, standing water, and used tires — including those working in agriculture, such as migrant and seasonal farm workers — may be at increased risk of mosquito bites and related diseases.
The virus also affects wildlife and domesticated and farm animals. Horses are a risk of developing West Nile virus. Consult your veterinarian about vaccinating your horses against the virus.
The number of mosquito pools — samples of 10-50 mosquitoes — that test positive in any area may indicate the risk of human exposure and infection, said Greg Barron, manager of North Morrow Vector Control District. He recommends people and animals be protected against mosquito bites.
“Although mosquitoes are an inevitable part of summer, mosquito bites don’t have to be—they are preventable,” said Emilio DeBess, public health veterinarian. “You can take simple steps to protect yourself and reduce the risk of contracting West Nile disease.”
DeBess offers these tips for protecting yourself against mosquitoes:
- Eliminate sources of standing water that are a breeding ground for mosquitoes, including watering troughs, bird baths, ornamental ponds, buckets, wading and swimming pools not in use, and old tires.
- When engaged in outdoor activities at dusk and dawn when mosquitoes are most active, protect yourself by using mosquito repellants containing DEET, oil of lemon eucalyptus or Picardin, and follow the directions on the container.
- Wear long-sleeved shirts and long pants in mosquito-infested areas.
- Make sure screen doors and windows are in good repair and fit tightly.
Additional information about West Nile virus can be found on the Oregon Health Authority website.
