Public health officials in Fresno and Tulare counties are reporting the infection of residents with potentially fatal mosquito-borne diseases such as West Nile virus and St. Louis encephalitis virus.

The Tulare County Health and Human Services Agency announced the infection of five human cases of the West Nile virus on Monday.

And, last Friday, the Fresno County Department of Public Health announced the detection and report of the St. Louis encephalitis virus, which derives from the West Nile family.

West Nile has been detected in multiple locations across Tulare County, and samples there indicate that SLEV may also be present.

Virus Symptoms

According to the Centers for Disease Control and Prevention, the West Nile virus and SLEV are transmitted to humans when bitten by infected mosquitoes. There is no vaccine or medication for treatment.

Most people infected with West Nile or SLEV will have few to no symptoms. However, for those who do experience symptoms, individuals will begin to have flu-like symptoms such as headaches, dizziness, nausea, and general weakness lasting 5-to-15 days.

More severe symptoms — stemming from central nervous system infections — include stiff neck, confusion, disorientation, dizziness, tremors, and unsteadiness.

In very rare cases, people go into comas, develop meningitis or encephalitis, or die.

For the most part, the disease is generally milder in children and young adults. The risk of dying increases in older adults, the CDC says.

Watch: How to Safeguard Against Mosquitoes

County Health Officials Urge Individuals To Be on Alert

Tulare County health officials urge residents to keep an eye out for homes that are unoccupied and that may have swimming pools or backyard ponds that are breeding grounds for mosquitoes.

“Due to this increased activity and these reported cases, we strongly encourage residents to use safeguards to reduce their risk of contracting both West Nile virus and SLEV through mosquito bites,” said Tulare County Public Health Officer Dr. Karen Haught.

Fresno County health officials recommend that residents contact their local mosquito control district to report standing water, neglected pools, dead birds, or any other mosquito problems.

Fresno County Interim Health Officer Dr. Rais Vohra says, “This positive case is a strong reminder that everyone should be taking every precaution to protect themselves and their families from mosquito bites in order to prevent vector-borne diseases.”

Safety Precautions and Preventions

FCDPH recommends following the “Three D’s” for protection against mosquito bites.

The first D stands for “Deter” as a reminder to apply any insect repellant containing DEET that will deter any mosquito bites.

The second D stands for “Dawn and Dusk, accounting for the mornings and evenings when mosquitos are more likely to bite.

The third D stands for “Drain,” to help individuals remember to drain any source of standing water. That means emptying flower pots, old car tires, buckets, and other containers while also ensuring windows and drains are covered with screens.

Contact Information

To report areas of standing water that may be a breeding area for mosquitoes, contact your local mosquito abatement districts.

To reach the Fresno County Mosquito Control District visit its website online at https://fresnocountymosquito.org/ 

Tulare County has three mosquito abatement districts providing abatement services to residents:

1. Delta Vector Control (Mosquito Abatement District) – Covers the northern portion of Tulare County. Contact the Visalia Office at (559) 732-8606 or visit online at: http://www.deltavcd.com/.
2. Tulare Mosquito Abatement District – Covers the western portion of Tulare County. Contact the Tulare Office at (559) 686-6628 or visit online at: https://www.tularemosquito.com/.
3. Delano Mosquito Abatement District – Covers the southern portion of Tulare County. Contact the Delano Office at (661) 725-3114 or visit online at: https://delanomosquito.com/.

All residents are encouraged to report dead birds by visiting www.westnile.ca.gov or by calling toll-free 1-877-WNV-BIRD (968-2473).