Mosquito Reports

Stay up to date on mosquito-borne virus activity within the District. Delta Mosquito and Vector Control District mosquitoes and dead birds for West Nile Virus (WNV), St. Louis Encephalitis Virus (SLEV), and Western Equine Encephalitis Virus (WEEV).

2022 Mosquito-borne Virus Activity in the District

LAST UPDATED: October 17, 2022










2022 Weekly Updates

Arbovirus testing has started for the season. Dead birds can be reported to 1-877-968-2473 or directly to the District at 559-732-8606. Activity within the District is updated weekly. For information about WNV in the entire state of California, please visit

Mosquito Samples

West Nile Virus: 978*      St. Louis Encephalitis Virus: 8*      Western Equine Encephalitis Virus: 0

There were 3 new WNV positive mosquito samples. So far this year, West Nile virus has been detected in mosquito samples from the following cities and regions: (7) Calgro, (2) Cutler, (14) Delft Colony, (83) Dinuba, (11) Exeter, (3) Farmersville, (3) Goshen, (8) Ivanhoe, (6) north Kings River, (4) Orosi, (51) Peral, (7) Rural, (49) Sequoia Fields, (1) Seville, (3) south Kings River, and (725) Visalia.  Additionally, SLEV was detected in the following cities and regions: (8*) Visalia.

In 2022, a total of 4,671 mosquito samples have been tested so far with 975 samples positive for WNV, 5 samples positive for SLEV, and 3 samples co-infected with WNV and SLEV.

*3 samples tested positive for both WNV and SLEV.

A sample may contain up to 50 individual mosquitoes.


Dead Birds

West Nile Virus: 2         St. Louis Encephalitis Virus: 0         Western Equine Encephalitis Virus: 0

There were no new WNV positive dead bird from Visalia this week. Eight dead birds have been tested in 2022.

Report dead birds to the WNV call center at 1-877-968-2473. Dead birds may be testable for WNV, SLEV, and WEEV. 


Human Cases

West Nile Virus: 3         St. Louis Encephalitis Virus: 0         Western Equine Encephalitis Virus: 0

Three (3) probable human cases of WNV have been reported to Delta MVCD in 2022.

The Tulare County Public Health Department reports human cases to the District.

Service Request? Get in Touch.


1737 West Houston Ave
Visalia, CA. 93291
Ph. 559-732-8606
TF. 877-732-8606
Fax. 559-732-7441


7:30 AM to 4:00 PM (excluding holidays)