Neighboring Butte County has reported a death due to complications of West Nile Virus (WNV) infection in an individual between the ages of 40-50 years The individual suffered from a severe, neuro-invasive WNV illness. There have been 13 human cases of West Nile Virus and 3 deaths in California in 2024. While Nevada County has not experienced any West Nile Virus activity this year, there have been many cases of infected mosquitos and birds in the past as well as a human case last year.
West Nile Virus is spread through mosquito bites and can infect birds, chickens and horses in addition to humans. Fortunately, most people who get infected with West Nile Virus have no symptoms. However, about 20% of infections lead to fever, headache, fatigue and body aches and less than 1% of infections can have severe neurologic effects like meningitis or paralysis. Severe illness is most likely to occur in people age 50 and older, and in individuals with chronic medical conditions such as hypertension and diabetes.
Dr. Sherilynn Cooke, Nevada County Public Health Officer, reminds residents “to take reasonable precautions to avoid mosquito bites.” To reduce the risk of being infected with West Nile Virus residents are encouraged to practice the “Three Ds”:
- DAWN and DUSK - Remain indoors at dawn and dusk when mosquitos are most active, or wear long sleeve shirts and pants during dusk and dawn.
- DEET - Use a mosquito repellant containing DEET, Picaridin, oil of eucalyptus, or IR3535 as active ingredients before going outdoors. Always use according to label instructions. DEET can be used safely on infants and children 2 months of age and older.
- DRAIN - Remove water standing from bird baths, pet dishes, flowerpots, old tires, neglected swimming pools and any other source of standing water which is not fresh. Mosquitoes lay eggs on stagnant water. For standing water that cannot be eliminated consider adding “Mosquito Dunks” or mosquito fish which feed on mosquito larva.
The County Environmental Health Department’s Vector Control department can assist with assessing your site for potential breeding locations for mosquitoes and can provide mosquito fish for stand-alone ponds and animal watering basins. Please contact the Environmental Health Department at (530) 265-1500.
For further information on West Nile Virus please see these resources:
Nevada County West Nile Virus and Mosquito Prevention - https://www.nevadacountyca.gov/2291/West-Nile-Virus-Mosquito-Prevention
California Department of Health - http://www.westnile.ca.gov/
Centers for Disease Control and Prevention - http://www.cdc.gov/westnile/index.html
