Health officials detect West Nile Virus in Visalia

Both West Nile Virus and St. Louis Encephalitis Virus were detected during the 2018 season


VISALIA – Mosquitoes in Visalia have tested positive for West Nile Virus (WNV).

Tulare County Public Health officials announced on May 23 that a sampling from a mosquito trap in southwest Visalia tested positive for the disease, which can be serious for people over the age of 50. The Delta Vector Control District, the testing agency, and the Tulare County Health & Human Service Agency’s Public Health Branch are asking Visalia residents to be vigilant against mosquito bites.

WNV is an illness caused by the bite of an infected mosquito. Symptoms of WNV can vary in severity, and though most individuals experience minimal to no effects, symptoms can include fever, headache, body aches, skin rash, and swollen lymph nodes, while severe symptoms include disorientation, coma, tremors, convulsions, and paralysis. If you experience symptoms after being bitten, contact your local physician or clinic.

Mosquitoes are infected with WNV by taking a blood meal from a bird infected with WNV. It is imperative that community members take precautions to prevent being bitten by mosquitoes and report dead birds and incidences of high mosquito presence.

To reduce the risk of being bitten by mosquitoes, Tulare County residents are strongly urged to:

  • Report mosquito presence (anonymously, if you like) by calling the Delta Vector Control District, or your local vector control agency, toll-free, at 1-877-732-8606 or by reporting online at, or on its Facebook page (, Twitter (@DeltaVCD), or Instagram (@DeltaVCD) accounts.
  • Apply an EPA-registered insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535 according to label instructions, especially in the early morning and evening.
  • Wear long-sleeved shirts and pants if outside in the early morning and evening.
  • Make sure that doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens that have holes.
  • Eliminate standing water and containers that can hold water from around the home.

Find out about mosquito reports all over the state of California by logging on to A Tulare County map of virus activity for the DVC area is viewable on the Delta Vector Control District homepage at

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