BOARDMAN — The North Morrow Vector Control District in a press release reported it detected West Nile virus in mosquitoes at a testing site in Morrow County.

The mosquitoes are the first to test positive for the disease in Morrow County in 2021.

“North Morrow Vector Control District was notified that seven mosquito pools collected on the night of Tuesday, Aug. 3, tested positive for West Nile virus. The pools were collected in the east rural Boardman area,” Greg Barron, manager of control district, said in a press release. “The area was treated with our truck mounted fogging units on Aug. 4 and again on the night of Aug. 9.”

Barron said the vector control district trapped the Boardman area again the night of Aug. 10 and on Aug. 11 shipped mosquitos for testing at the Oregon State University Diagnostic Laboratory.

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, Barron said. He recommended 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,” Dr. Emilio DeBess of the Oregon Health Authority said in a press release. “You can take simple steps to protect yourself and reduce the risk of contracting West Nile disease.”

West Nile virus is spread to humans through the bite of an infected mosquito. Most infected people will show little or no signs of disease.

The incubation period is usually two to 14 days. Rarely, infected individuals may develop neuroinvasive 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.

About 1 in 5 people who are infected develop a fever with other symptoms, such as headache, body aches, joint pains, vomiting, diarrhea or rash. Most people with febrile illness due to West Nile virus recover completely, but fatigue and weakness can last for weeks or months. It is important that you contact your health care provider if you experience any of these symptoms.

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.

While risk of West Nile disease is low, a handful of people get it each year in Oregon. The virus also affects wildlife and domesticated and farm animals.

In 2019, nine human cases of West Nile virus infection were reported in Oregon, with 85 mosquito pools and seven horses also found to be positive for the virus. In 2018, there were two human cases, with 57 mosquito pools and two horses testing positive. Last year was relatively mild for West Nile, with only three mosquito pools and one bird found to be positive for the virus.