Mosquitoes in Visalia, Dinuba and Orosi have tested positive for West Nile virus, health officials in Tulare County said Wednesday.
The Delta Vector Control District reported the mosquito findings last week.
Tulare County residents should be on guard to protect themselves as outdoor activities ramp up on Memorial Day weekend, health officials said.
West Nile virus is transmitted to humans by mosquitoes, and there is no vaccine or medication to treat the virus. Most people infected have no symptoms, however, about one in five develop a fever with other symptoms.
Standing water and neglected swimming pools in backyards are common breeding grounds for mosquitoes. People should drain standing water sources and report neglected pools to mosquito control districts.
If outside during dusk and dawn in areas where mosquitoes are active, people should use an effective mosquito repellent, dress in long sleeves and pants.
Health officials ask people to call (877) 968-2473 to report dead birds and squirrels, which can be a signal of West Nile virus activity in an area. Reports also can be submitted online to the California West Nile website at www.westnile.ca.gov.