Another Southern California county has confirmed the discovery of mosquitoes carrying West Nile virus.
They were the first mosquito samples in Orange County to test positive for the virus this year, but 20 of California’s 58 counties have seen West Nile virus activity in 2024, according to the state Department of Public Health.
Orange County “has been very lucky this year,” said Brian Brannon of the county’s Mosquito and Vector Control District. In addition to the current heat wave, he noted that cooler temperatures there, especially at night, mean “we’re not seeing a lot of mosquitoes.”
according to The agency said the infectious insects were discovered in Huntington Beach during routine testing of the area. West Nile virus, which causes symptoms such as headaches and fever and can be fatal in rare cases, is only spread through blood-sucking in Southern California. Culex mosquito Mosquitoes feed at dawn and dusk.
Brannon said there’s no reason to panic. The threat to the public remains low in Orange and Los Angeles counties, and there have been no reports of bird deaths related to West Nile. birds Vulnerable to the virus, such deaths would be a clear sign that the disease is spreading.
So far this year, the state public health department counts 88 dead birds that have tested positive for the virus. Santa Clara and Sacramento counties account for most of the birds. Notably, there have been no human cases in California so far in 2024.
Residents who don’t want to be bitten by mosquitoes can reduce the risk by removing containers of stagnant water from their homes, such as uncovered outdoor grills and potted plants in saucers, where mosquitoes breed. Also, choose long-sleeved clothing and use an insect repellent that contains DEET, oil of lemon eucalyptus, or other effective active ingredients.
Brannon said other agencies in Southern California are also paying close attention, monitoring the types of mosquitoes and their numbers.
In recent years, invasive Aedes aegypti The number increased dramatically. These blood-sucking bugs only require a teaspoon of water to reproduce, and unlike blood-sucking bugs Culex mosquito, likes to bite people throughout the day. They can also spread diseases such as yellow fever, dengue fever and Zika virus.
“We’ve only seen West Nile so far this season,” Brannon said, “but we’re looking for any other potential diseases that may be spreading.”
The Greater 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 looking for more cases as heavy rainfall this year creates conditions for mosquito control.
“Right now we’re still in a normal season. We haven’t moved into any high-risk levels yet,” said Susanne Kluh, general manager of the Los Angeles County agency. She said it was normal for these mosquitoes, which love humidity and heat, to be more active in the valley.
“This virus amplifies faster in warmer temperatures,” Crewe said, noting that climate change is a boon for subtropical mosquitoes and the diseases they carry. Mosquitoes have the ability to adapt to “dry or cooler climates” and “they will continue to be distributed there,” she added.
This spring, vector control agencies across Southern California are trying a new and innovative way to stop the spread of the virus Aedes mosquito Mosquitoes – Release more mosquitoes. Tristan Alexander Hallum, director of scientific programs for the San Gabriel Valley Mosquito and Vector Control District, said the strategy, while counterintuitive, is exciting.
“We started developing different sterilization techniques to curb these populations,” Hallam said. Although it’s too early to have data on the effects of these efforts, the idea is that sterilizing male mosquitoes with radiation will begin to reduce the number of viable eggs. “Irradiation is a tried and tested method for different projects like screwworms.”
Hallam said concerns about mosquitoes contracting West Nile virus or other diseases should not stop anyone from participating in outdoor recreation this summer.
“I will never be afraid of the mosquito-borne pathogens that we see all the time,” Hallam said. “Right now we have normal levels of West Nile virus in our area.”
