First Mosquito Sample Tests Positive for West Nile Virus in Yolo County

FIRST MOSQUITO SAMPLE TESTS POSITIVE FOR WEST NILE VIRUS IN
YOLO COUNTY
Activity continues in areas of Sacramento County
 
Elk Grove, Ca— The Sacramento-Yolo Mosquito & Vector Control District announced today that the first mosquito sample in Yolo County has tested positive for West Nile virus. The mosquito sample was collected from the city of Madison.

At the same time, West Nile virus activity continues to increase in Sacramento County where five dead birds and four mosquito samples collected from different areas also tested positive for the virus today.  “West Nile virus activity is steadily building across our region as we move through the peak of mosquito season,” said Gary Goodman, District Manager. The increase in West Nile virus activity follows the first reported human case in Sacramento County last week involving a woman in her 60’s.  “A human case reminds us that West Nile virus is definitely present in our communities and that mosquito prevention is more important than ever,” added Goodman.
 
In response to the recent findings, the District will continue to monitor West Nile virus activity through widespread mosquito trapping and testing and will perform ground treatments in areas where positive mosquitoes have been found to quickly decrease populations and protect public health. 

While West Nile virus remains a priority, another ongoing concern is the spread of invasive Aedes aegypti mosquitoes. First detected within the District in 2019, these aggressive daytime-biting mosquitoes have continued to spread throughout many communities. They pose a significant public health concern because they are capable of transmitting viruses such as dengue, Zika, and chikungunya. In response to their continued spread, the District is launching a Sterile Insect Technique (SIT) program in Rosemont. Beginning tomorrow, sterile male mosquitoes will be released weekly throughout a designated 120-acre area. Male mosquitoes do not bite. When sterile males mate with wild female mosquitoes, the eggs do not hatch, helping to reduce mosquito populations over time.

For current information about District activities, please visit www.FIGHTtheBITE.net. Residents may also subscribe to mailing lists to receive email notifications for upcoming mosquito treatments by zip code. To sign up, go to Spray Notifications on the website.
 
2026 West Nile virus activity update:
 
Sacramento County:  24 mosquito samples and 38 dead birds have tested positive for West Nile virus to date. 
 
Yolo County:  1 mosquito sample and 2 dead birds have tested positive for West Nile virus to date