New samples of mosquitos found in Los Angeles and Orange counties have tested positive for West Nile virus, bringing the the total number of infected samples found this year up to 140 in both counties, health officials said Friday.
In Los Angeles County, infected samples were found in Boyle Heights and Whittier last week, raising the county's total up to 28 so far this year. Infected samples found in Anaheim, Buena Park, Fullerton and Stanton brought Orange County's 2019 total up to 114.
The virus is transmitted to people and animals by the bite of an infected mosquito, and is the leading cause of mosquito-borne disease in the U.S., according to the Centers for Disease Control and Prevention.
At least 89 people have contracted West Nile in the state this year as of Sept. 2019. Four of the cases were in L.A. County, according to a report by the California Mosquito-borne Virus Surveillance and Response Program.
Californians die every year as a result of contracting the virus.
Last year, 11 people died of West Nile in California, and 44 died the year before, according to the report.
A Tustin woman in her 50s was diagnosed with West Nile virus fever in Aug. 2019, becoming the first person to contract the virus in Orange County this year.
"West Nile virus is endemic in Los Angeles County," the Greater Los Angeles County Vector Control District said in a news release.
The agency said the risk of contracting the virus increases as temperatures rise and bring more mosquitos to California.
Most people who contract the virus don’t experience any symptoms, but some may develop a fever, headache, body aches, nausea, or a skin rash, and symptoms can last for months.
About 1 out of 150 infected people develop a serious, sometimes fatal, illness, according to the health officials.
There are no vaccines to prevent the virus in people, but residents can reduce the risk of contracting it during mosquito season by using insect repellent and wearing long-sleeved shirts and long pants while outdoors.
Water left standing for more than a week in containers like flower pots, fountains and pet dishes, or in unmaintained pools, can become a breeding habitat for mosquitoes and should be discarded, health officials said.
In an effort to reduce the number of mosquitoes and limit the spread of the virus, Orange County health officials said they will be using cold fogging machines to spray the mosquitoes in neighborhoods where infected samples were found.
Residents can check the spraying schedule and see where the infected samples were found online.
Los Angeles County residents can call 562-944-9656 for more information on the virus. Orange County residents can visit ocvector.org