Rare Mosquito Disease Confirmed in Franklin County

Health officials with the Benton Franklin Health District have confirmed a Franklin County resident caught a rare disease linked to mosquitos over the summer.

St Louis Encephalitis (SLE) is transmitted through the bite of an infected mosquito and cannot be passed on from person to person. It can cause inflammation of the brain in rare cases and flu-like symptoms four to 14 days after infection. Long-term disability or even death can occur in rare instances. The risk to public health is low.

Outbreaks and epidemics of SLE primarily happen in the Mississippi Valley and along the Gulf Coast and more recently in the Southwest.

The Benton Franklin Health District says the last reporting of SLE in the Mid-Columbia dates back to 2005 in a flock of chickens.

Before this summer, the last locally acquired human case of SLE in Washington was reported in 1972.

"In the future, we might see more cases of mosquito-borne diseases in different places due to climate change. Diseases carried by insects, like mosquitos, can become more common and spread to new areas as the climate gets warmer,” said Erin Hockaday, Sr. Manager of Surveillance & Investigation, BFHD.

SLE prevention is similar to that of the West Nile Virus:

• Use insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus on exposed skin and/or clothing. The repellent/insecticide permethrin can be used on clothing to protect through several washes. Always follow the directions on the package.
• Wear long sleeves and pants when weather permits.
• Have secure, intact screens on windows and doors to keep mosquitoes out.
• Eliminate mosquito breeding sites by emptying standing water from flowerpots, buckets, barrels, and other containers. Drill holes in tire swings so water drains out. Empty children’s wading pools and store on their side after use.

For more information on St. Louis Encephalitis and mosquito-borne diseases, you can visit the CDC's St. Louis Encephalitis page.

Other diseases carried by mosquitos include:

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