Carla B. Hass



El Dorado County health officials received confirmation that a bird found in the Lotus area of El Dorado County tested positive for West Nile Virus, the first this year.  The bird, a House Finch, was collected on July 21, 2023. West Nile Virus activity was not detected in El Dorado County in 2022.

Confirmation of the West Nile virus positive bird means the virus is circulating between birds and mosquitoes and there is heightened risk of infection in humans.

"Birds are common carriers of West Nile virus," said Olivia Byron-Cooper, Interim Director of Health and Human Services. "Mosquitos bite birds and become infected with the virus then pass the infection when they bite people or animals. It is not spread from person to person."

While most people infected with the virus show no symptoms, some may have high fever, severe headache, tiredness and/or a stiff neck that can last several days to several weeks. The most serious cases of West Nile virus infection can lead to encephalitis, an inflammation of the brain, which can be fatal.  

Mosquito surveillance programs are in place throughout the County. Activities include trapping and identifying mosquitoes, treating neglected swimming pools, and reporting and testing dead birds. The El Dorado County Public Health Division conducts human surveillance activities and health care providers are asked to routinely test human cases of viral meningitis and encephalitis for West Nile virus.

"There are simple steps residents can take to reduce the likelihood of contracting and spreading West Nile Virus," said Byron-Cooper.
These include:

  • Drain standing water around the property and keep water in swimming pools, ponds and water troughs circulating or treated with "Mosquito Dunks" or mosquito fish.
  • Apply insect repellent that contains DEET or another approved substance (e.g. picaridin, oil of lemon eucalyptus or IR 3535) on exposed skin when outdoors.
  • Dress in long sleeves and pants when outdoors among mosquitoes. Mosquitoes are most active at dusk and dawn.
  • Make sure doors and windows have tight fitting screens, kept in good condition.
  • Report dead birds and tree squirrels to the State West Nile Virus hotline at (877) WNV-BIRD (877-968-2473) or online at  Wear gloves and place the dead bird or squirrel in a double plastic bag if you dispose of it yourself.

Mosquito problems and neglected swimming pools should be reported to the El Dorado County Environmental Management Department at (530) 621-5300 on the West Slope or (530) 573-3450 in South Lake Tahoe.

Additional West Nile virus information can be found at or


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