By Shannon Weidemann (McKone) on Monday, August 14th, 2023 in Columbia Basin News More Top Stories Northeastern Oregon News
EASTERN OREGON – (Release from Oregon Health Authority) Health officials are reminding people heading outdoors in eastern Oregon to prevent mosquito bites after a recent jump in the number of mosquito pools – collections of up to 50 insects – testing positive for West Nile virus, according to local vector control districts.
Emilio DeBess, D.V.M., state public health veterinarian at Oregon Health Authority’s (OHA) Public Health Division, said high heat combined with sporadic precipitation has created perfect conditions for mosquito growth in recent weeks. As a result, eastern parts of the state are seeing more mosquitoes and a corresponding increase in traps containing West Nile-positive insects.
The increase in mosquito populations may be behind new human cases of the virus.
“Eastern Oregon has seen a little bit of rain, leading to additional water available for mosquitoes to lay eggs,” said DeBess. “We saw an increase of 13 West Nile-positive mosquito pools in one week, 10 of them in Baker County, and two presumptive human cases.”
So far in 2023, a total of 22 mosquito pools have tested positive for the virus. Eleven have been in Baker County, seven in Malheur County, two in Union County, and one each in Jackson and Umatilla counties.
Last year, there were five human West Nile virus cases in Oregon, and three cases among horses, with 45 positive mosquito pools. There also were five human cases in 2021, along with eight horse cases, two bird cases and 75 positive mosquito pools.
Groups at risk for severe disease include adults 50 and older, immunocompromised people and those living with certain conditions such as diabetes and high blood pressure.
While most infected people show little to no signs of disease, one in five show signs of West Nile fever. Flu-like symptoms can last from a few days to several weeks and may include fever above 100 degrees Fahrenheit, severe headaches, stiff neck, mental confusion, muscle weakness, shaking, paralysis or rash. Anyone experiencing such symptoms should contact their health care provider.
The easiest and best way to avoid mosquito-borne diseases is to prevent mosquito bites:
Additional resources, such as frequently asked questions and information on finding local mosquito control agencies, are available on OHA’s West Nile virus page and CDC website. Current and past virus data can be found on the West Nile Virus Activity page.