Mosquito with West Nile virus found in Costa Mesa adds to county’s upward trend

A mosquito captured in Costa Mesa this week has tested positive for West Nile virus, adding to signs that the disease could be even more prevalent in Orange County this year than in 2015, when it was considered an epidemic, according to county officials.

Two major indicators of West Nile — the number of mosquitoes carrying the virus and the number of dead birds found to be infected — are up countywide in 2016, according to Jared Dever, a spokesman for the Orange County Mosquito and Vector Control District.

As of July 12, the agency had collected 19 mosquitoes and 12 dead birds that tested positive for West Nile. At the same time last year, officials had found 12 mosquitoes and five dead birds carrying the virus.

“You can see we’re trending ahead of even last year, which was a pretty bad epidemic year for us,” Dever said.

Last year, the virus infected 97 people in Orange County and was blamed for eight deaths, according to health officials.

So far this year, there hasn’t been a recorded case of West Nile infecting a human in Orange County, according to the OC Health Care Agency.

However, it may be only a matter of time. Dever said officials assume infections are happening right now, but it can take weeks before they’re recorded. For that to happen, a person showing symptoms of the virus has to get treatment from a medical provider, who will report it to health officials.

“It’s a long process,” Dever said.

Symptoms can include fever, headache, body aches, convulsions and muscle weakness. Experts say people who believe they are infected should see a physician immediately.

A mosquito trapped Monday was the first one captured in Costa Mesa this year that tested positive for West Nile. It makes Costa Mesa the 14th city in Orange County to show signs of the virus in 2016, according to Vector Control.

Three West Nile-positive mosquitoes were found in Costa Mesa last year.

“This year, for whatever reason, is a particularly bad year for mosquitoes,” Costa Mesa Mayor Steve Mensinger said. Residents in the Lower Birds neighborhood on the northern edge of Fairview Park have been complaining about the pests for a while, he said.

On Wednesday, city staff met with Vector Control officials to talk about how they can tamp down on mosquitoes breeding in artificial wetlands in Fairview Park, according to Costa Mesa spokesman Dane Bora.

Mosquitoes coming from the wetlands are a different species than the one that tested positive for West Nile on Monday, Bora said. They’re less likely to carry the virus, but still capable, according to Vector Control.

Dever said the mosquito captured in Costa Mesa is a species that Vector Control watches more closely for West Nile. It’s typically found breeding in residential areas. Standing water from storms or in bird baths, pet dishes or even potted plants can attract the pests.

“They’re breeding in your own backyard and they’re coming indoors to feed on you at night,” Dever said.

Staff writer Luke Money contributed to this report.