Increase in OC mosquitoes draws concern, with West Nile found in nearby counties

Feeling itchy? COVID-19 isn’t the only virus out there to worry about.

The Orange County Mosquito and Vector Control District put out an alert on Tuesday, June 16, after observing an increase in mosquito activity in urban and coastal areas of the county.

While West Nile virus hasn’t yet been detected in Orange County this year, the three surrounding counties – Los Angeles, Riverside, and San Diego – have found the virus in mosquito samples.

“Our district lines are pretty invisible,” said Heather Hyland, public information officer for OCMVCD. “It’s just a matter of time, if we have surrounding counties that are West Nile positive, it is a high potential to have the positive mosquito in the trap.”

While the vector district typically finds a weekly average of 24 mosquitoes per trap, the latest increase marks the sixth consecutive week of higher than average counts.

Overall this year, they’ve found an average of 110 mosquitoes per trap, nearly five times higher than last year’s numbers and double the county’s five-year average.

“High mosquito abundance is one factor that increases the risk for West Nile virus transmission when virus activity is present. However, OCMVCD currently has not detected any (virus) in our surveillance program,” district Director of Scientific Services Robert Cummings said.

With more mosquitoes comes a higher likelihood that one could bite an infected bird and then transmit the virus to humans.

“We’re just on that line of caution, we want people to know there is a high abundance, which means more bites,” Hyland said.

West Nile is most often spread by the bite of an infected mosquito. The mosquitoes are carriers, or vectors, that become infected when they feed on infected birds. Infected mosquitoes can then spread West Nile to humans and other animals when they bite; it is not spread between people through casual contact such as touching or kissing, or by breathing in the virus.

Part of the reason for the higher-than-normal numbers could be the rain in May or hot weather so far this summer, Hyland said. There are also not only native mosquitoes hanging around, but invasive Aedes mosquitoes, an aggressive species that bite in the daytime and can bite multiple times.

West Nile virus is a mosquito-borne disease originally found in Africa. In 1999, the virus was detected in the eastern United States; since then it has spread throughout the U.S. and is well established in most states, including California.

The symptoms for West Nile can be similar to the flu, with high fevers and body aches, though it does not come with respiratory issues. Two percent of those infected have severe cases, and 20% get mild symptoms. Some people have reactions that lead to a rash or brain inflammation that can put them in a coma.

“You never know how your body is going to react to it or that strain,”  Hyland said.

Some mosquito “hot zones” include Anaheim, Santa Ana, Fullerton, Buena Park, Garden Grove and Westminster. Areas like Bolsa Chica Wetlands, Big Canyon in Newport Beach, the UCI Marsh are also showing high numbers of mosquitoes.

Julie Alston Kurt, of Dana Point, said she and her family have been bitten while out enjoying their fire pits a few times in the past week.

“They ooze orangeish pus and are so itchy,” she wrote on social media, noting the welts and itchiness lasted over a week. “Weird thing is a few times we have had jeans and sweatshirts on and they go right through.”

The vector district is asking residents in high mosquito population areas to take precautions, and it will continue to look for and treat water sources that could harbor breeding mosquitoes.

How to reduce opportunities for mosquitoes to breed: 

• Dump and drain any containers of water at least once a week

• Clean and scrub bird baths and pet water bowls weekly

• Do not transport or share plant clippings rooted in water

• Drill a hole or puncture containers to eliminate standing water

To prevent mosquito bites, follow these tips:

• Apply mosquito repellents to exposed skin before going outdoors

• Wear repellent containing DEET, picaridin, IR3535, or oil of lemon eucalyptus

• Close all unscreened doors and windows to prevent mosquitoes from entering your home or space; repair broken or damaged screens

• Wear long-sleeved shirts and long pants, and opt for lighter-colored clothing

More info: ocvector.org

Source: Orange County Register