Mosquito control district warns residents of viruses

After indicators of West Nile virus and St. Louis Encephalitis were found in local communities, Delta Mosquito and Vector control urges citizens to take caution against mosquitoes

Karis Caddell
Published July 11, 2023  • 
6:00 pm

VISALIA – Delta Mosquito and Vector Control is advising residents to repel their chances of contracting West Nile virus and St. Louis Encephalitis after positive samples were found in mosquitoes in the area.

Announced on July 10, Delta Mosquito and Vector Control District found positive tests in multiple locations for the West Nile virus and St. Louis Encephalitis. Vector control is warning residents to minimize their chances of infection by taking precautions against mosquitoes.

Thus far, the Delta Mosquito and Vector Control District reported a total of eight mosquito samples that have tested positive for West Nile virus (WNV) and one positive test for St. Louis Encephalitis virus (SLEV). The positive SLEV mosquito sample was collected from one location in Visalia, and WNV positive mosquito samples were collected from eight locations in Visalia, Dinuba and Farmersville.

The St. Louis Encephalitis virus, and West Nile virus, are transmitted to people and animals through the bite of an infected female mosquito. Mosquitoes become infected when they feed on infected birds. After contracting the infection, the mosquitoes then spread SLEV and WNV to humans when they bite them.

While most infected people will have no symptoms, others will develop fever, headaches and body aches. Some cases require hospitalization and, in rare cases, death occurs. People with symptoms should contact their healthcare provider. Adults over 50 and those with compromised immune systems are at increased risk of serious complications.

“However, anyone who develops symptoms should seek medical care immediately,” the district stated in a news release.

After storms swept through California this year, stagnant water became a concern for Delta Mosquito and Vector Control District as West Nile virus-infected mosquitoes staked their claim in the Central Valley; worsened by the fact that mosquitoes lay eggs in stagnant water frequently, and not just one egg at a time. 

According to Dr. Mustapha Debboun from the Delta Mosquito & Vector Control District, a female mosquito can lay roughly 500 eggs at once. Residents may see mosquitoes gravitate to their homes if there is a lot of standing water or litter. The influx of water scattered throughout the area could possibly result in an increase in the mosquito population; however, the vector control district will be measuring that throughout the mosquito season.

Delta Mosquito and Vector Control District advices reducing the risk of contracting mosquito-borne diseases such as West Nile virus by following these guidelines:

  • Prevent mosquito bites by using an EPA-registered insect repellent when going outside around dawn and dusk, when these mosquitoes are most active. Follow the instructions listed on the EPA-registered insect repellent product label.
  • Cover up. Wear long sleeve shirts and long pants when mosquitoes are most active to reduce bites.
  • Check window and door screens to prevent mosquitoes from entering your home.
  • Reporting and testing dead birds is one way to check for the presence of West Nile virus in the environment.

The district also advises that residents prevent mosquitoes from the area around their home by doing the following:

  • Inspect yards for standing water sources. Drain water that collects under potted plants, bird baths, tires, and any other water-holding containers.
  • Screen the openings of lawn drains.
  • Clean and scrub pet dishes and water features weekly.
  • Swimming pools, ponds and fountains require working pumps and regular maintenance. Report neglected swimming pools anonymously to Delta Mosquito and Vector Control District for treatment.
  • Request free mosquitofish for backyard ponds, horse troughs, or neglected swimming pools. Free mosquitofish are available at the District office located in Visalia at 1737 W Houston Ave.

Every effort is being made to locate areas of standing water where mosquitoes may breed, including but not limited to catch basins, storm drain systems and neglected swimming pools. Neglected swimming pools continue to be a mosquito breeding issue in the District. Neglected swimming pools can be reported to the District anonymously for treatment at 559-732-8606.

Karis Caddell