YUBA COUNTY, CA (MPG) - Yuba County Public Health has confirmed the first human case of West Nile virus (WNV) in Yuba County this year. This is the first known West Nile Virus human case in California for the 2024 season. West Nile virus is generally active June through October. 

People infected with West Nile virus fall into three categories: 

No symptoms/asymptomatic (8 in 10 people) 

Mild to moderate fever illness with fatigue and body aches (1 in 5 people) 

Severe illness with neurologic symptoms such as encephalitis or meningitis (less than 1 in 150 people). 

For those who develop a severe West Nile virus illness, symptoms may last several weeks, and some symptoms may be permanent.

There is an increased risk of West Nile virus throughout Sutter and Yuba counties. “We continue to see increased virus activity and detections in our surveillance system. The risk for human infection is high,” said Stephen Abshier, District Manager. “Residents need to remain vigilant in protecting themselves from being bitten by mosquitoes,” added Abshier. Residents should inspect their yards for anything holding water. Regular landscape irrigation or unseasonable rains can provide mosquitoes with good breeding habitat. Simply draining or dumping water will prevent new mosquito breeding. 

“The best way to prevent West Nile virus infection is to avoid mosquito bites. We want to remind everyone to stay protected by wearing long pants and long sleeves, especially at dawn and dusk when mosquito activity is high, and by wearing an effective mosquito repellent,” said Bi-County Public Health Officer, Dr. Phuong Luu.

West Nile virus is transmitted to humans and animals by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Residents can reduce the risk of infection by practicing the “Three Ds”: 

DEET – Use a proven insect repellent like DEET. Other recommended repellents include:  picaridin, oil of lemon eucalyptus, para-menthane-diol, IR3535 or 2-undecanone. Always use repellent according to label instructions. DEET is safe for use on children when used as directed. 

Dawn and Dusk – Mosquitoes that transmit West Nile virus bite in the early morning and evening. Wear proper clothing and repellent if outside during these times. Make sure that doors and windows have tight-fitting screens to keep mosquitoes out. Repair or replace screens with tears or holes. 

Drain – Mosquitoes lay their eggs on standing water. Eliminate or drain all sources of standing water on your property, including flowerpots, car tires, rain gutters, and pet bowls. For standing water that cannot be drained such as fountains, ponds, etc., consider adding “Mosquito Dunks” or mosquito fish, which feed on mosquito larvae.

In response to recent findings and increased virus activity, District staff will continue to trap mosquitoes for testing, continue our disease surveillance program, and treat areas of high West Nile virus activity with truck mounted foggers to reduce the adult mosquito population. Spray areas can be viewed at the district’s website at https://sutter-yubamvcd.org/. A surveillance map can be found there as well, which shows the location of West Nile virus positive dead birds, mosquito collections, and sentinel chickens.

For more information about West Nile virus, please visit: westnile.ca.gov.