Orange County mosquito samples positive for West Nile virus

In another Southern California county, West Nile virus.

These were the first mosquito samples to test positive for the virus in Orange County this year, but West Nile virus outbreaks have already begun in 20 of California's 58 counties, according to the state Department of Public Health. Virus activity 2024.

“We've been pretty lucky this year,” said Brian Brannon of the Orange County Mosquito and Vector Control District. Current heat wave Meanwhile, he noted, because temperatures are low locally, especially in the evenings, “you don't see many mosquitoes.”

according to Officials said the infected insects were found in Huntington Beach during a routine community inspection. West Nile virus causes symptoms such as headaches and fever and can be fatal in rare cases, but in Southern California it is spread only by blood-sucking insects. Ieca Mosquitoes gather in large swarms at dawn and dusk.

Brannon said there's no reason to panic. No bird deaths from West Nile virus have been reported in Orange and Los Angeles counties, and the threat to the public remains low. easily influenced The risk of contracting the virus is low and such deaths would be a clear sign that the disease is spreading.

State Department of Public Health I counted 88 There have been 10 cases of dead birds testing positive for the virus so far this year, mostly in Santa Clara and Sacramento counties. Notably, there have been no human cases in California so far in 2024.

Residents who don't like being bitten Mitigate the risks Remove pools of water around your home that mosquitoes can breed in, such as under open outdoor grills or in potted plants with saucers, and wear long-sleeved clothing and insect repellent with DEET, lemon eucalyptus oil, or other effective active ingredients.

Brannon said other agencies across Southern California are also on high alert and are monitoring mosquito species and populations.

In recent years, invasive Aedes aegypti They are multiplying rapidly. These blood-sucking bugs only need a teaspoon of water to reproduce. IecaThey can bite at any time of the day and can spread diseases such as yellow fever, dengue fever, and Zika.

“We've only seen West Nile so far this season,” Brannon said, “but we're also keeping an eye out for other potential diseases that could be spreading.”

The Los Angeles County Vector Control District has found three cases of West Nile virus in mosquito samples from the San Fernando Valley, and officials are on alert for more cases as heavy rains this year have created conditions for mosquito populations.

“We're still in a normal season. We're not at a high-risk level,” said Susan Crews, general manager of the Los Angeles County Sheriff's Office. She said it's normal for these mosquitoes, which love humidity and heat, to be active in the Valley.

“Viruses grow more quickly in warmer temperatures,” Crews said, noting that climate change favours subtropical mosquitoes and the diseases they transmit, adding that mosquitoes have the ability to adapt to “drier or cooler climates” where “they will continue to be distributed.”

In the spring, vector control agencies in Southern California tried new and innovative ways to stop vector spread. Aedes aegypti Mosquitoes — By releasing more stuff. Tristan Alexander-Hulme, science program director for the San Gabriel Valley Mosquito and Vector Control District, said the strategy sounds counterintuitive at first glance, but is an intriguing one.

“We're starting to develop a variety of sterilization techniques to try to control these mosquito populations,” Hulme said. It's too early to have data on the effectiveness of these efforts, but the idea is that by sterilizing male mosquitoes with radiation, we can begin to reduce the number of viable eggs. “Radiation is a proven method in various programs, including with screwworm flies.”

Hallam said fears of contracting West Nile or other diseases from mosquitoes should not discourage anyone from participating this summer. Outdoor recreational activities.

“I would never be afraid of a mosquito-borne pathogen that we see every day,” Hulme said, “and right now, West Nile virus is pretty common in our area.”