Additional mosquitoes test positive for West Nile virus in Baker County

BAKER CITY – West Nile virus, which is spread by mosquitoes, has been detected in five additional mosquito pools from various testing sites in Baker County, Ore., according to Oregon Public Health officials.

Four of the samples were collected from various testing sites in Keating Valley, approximately 12 miles east of Baker City. One pool was collected from a testing site approximately 4 miles north of Baker City.

Health officials are advising people in Baker County to take precautions against mosquitoes to avoid the risk of infection, including preventing mosquito bites. 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. 

About one in five 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.

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. 

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 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 Matt Hutchinson, Manager of Baker Valley 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,” DeBess says. “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.

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.

People should consult their health care providers if they have these symptoms. Health care providers can contact the Malheur County for information on West Nile virus testing.

Additional information about West Nile virus: 

Oregon Health Authority website: http://public.health.oregon.gov/DiseasesConditions/DiseasesAZ/WestNileVirus/Pages/survey.aspx

U.S. Centers for Disease Control and Prevention:

http://www.cdc.gov/ncidod/dvbid/westnile/ index.htm

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Elkhorn Media Group