Yolo County West Nile virus activity more than doubles in two weeks
YOLO COUNTY -- West Nile virus activity has more than doubled in Yolo County over the last two weeks due to triple-digit temperatures across the region.
The spike in activity is around Davis, Woodland, and surrounding areas, according to the General Manager for the Sacramento-Yolo Mosquito and Vector Control District.
Lab results confirmed the activity increase this week after twelve mosquito samples and two dead birds tested positive for the virus.
"We can probably expect perhaps, all things considered, a little bit of a dip because the mosquito numbers will go down as a result of the high temperatures," said Gregory Lanzaro, Ph.D., a Professor in the Department of Pathology, Microbiology, and Immunology at UC Davis.
Lanzaro said mosquitoes couldn't withstand higher temperatures, and the consecutive days of heat have likely caused mortality rates to go up. At the same time, the heat shortens the development time of a mosquito. So with more mosquitoes, there is more risk of carrying the West Nile virus or other viruses.
"Leading up into the beginning part of August, we had 20-25 positive mosquito pools; now, we have over 58 mosquito pools that have tested positive," said Gary Goodman, the General Manager for the Sacramento-Yolo Mosquito and Vector Control District.
In other Northern California counties, like San Joaquin County, the year has been average for mosquito activity. Right now, it's concentrated in the delta area.
"The virus inside their body amplifies quicker, that increases the risk to humans," said Aaron Devencenzi, the Public Information Officer for the San Joaquin County Mosquito and Vector Control District.
San Joaquin County has two scheduled days for mosquito spraying next week. The dates and locations of these mosquito control efforts are listed below.
- Ground spraying for adult mosquito control using DeltaGard® and/or Evergreen 5-25 is scheduled for the morning of Monday, Aug. 22, 2022, between 4 a.m. and 7:00 a.m. or, depending on weather, the morning of Tuesday, Aug. 23, 2022, between 4 a.m. and 7 a.m.
- Portion of Central Stockton: >North to Mendocino Ave., >South to Tuxedo Ave., >East to Pacific Ave., >West to Pershing Ave. See Map
- South of Linden — Peters Area: >North to Milton Rd., >South to Dietrich Rd., >East to S. Hewitt Rd., >West to Dietrich Rd. See Map
- Portion of Rural East Lodi: >North to Kettleman Ln., >South to Tokay Colony Rd., >East to Jack Tone Rd., >West to Hibbard Rd. See Map
- Aerial spraying for adult mosquito control using Dibrom is scheduled for the evening of Sunday, Aug. 21, 2022, between 8:15 p.m. and 11 p.m.