Tulare County has confirmed the first case of West Nile virus in 2018 in an individual in Porterville.
Fresno County has had three cases of West Nile so far this year, according to the California Department of Public Health.
Health officials in Tulare are warning residents to protect themselves from mosquito bites. This year, in addition to West Nile, samples of mosquitoes in Tulare County have shown a higher number of positive test results for St. Louis Encephalitis than in past years.
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The Tulare Mosquito Abatement District found 19 positive mosquito samples (between 10 and 50 female mosquitoes) capable of transmitting St. Louis Encephalitis virus. Last year, only three samples were positive for the virus. There have been five positive samples for West Nile virus, compared to 46 positive samples last year.
The Delta Vector Control District, which serves most of northern Tulare County, has had 77 positive mosquito samples for St. Louis Encephalitis so far this year and 23 positive samples for West Nile. Last year, it had 14 positive samples for St. Louis Encephalitis and 514 for West Nile virus.
Most people who are infected have few symptoms from West Nile and St. Louis Encephalitis, but both viruses can cause severe illness in a few people.
People should avoid being bitten by mosquitoes by applying insect repellent that contains DEET, picaridin, oil of eucalyptus or IR3535, according to label directions. Wearing long-sleeved shirts and long pants when outside also can protect against mosquito bites. And doors and windows should be tight-fitting.
Mosquitoes can breed in small amounts of water, and people are encouraged to check back yards to eliminate sources of standing water.