Los Angeles has one of its worst mosquito years, with West Nile cases at a near-decade high

Mixed · 2Los Angeles is having one of its worst mosquito years in recent history, with residents describing swarms in backyards and at outdoor restaurants. 1 2 Mixed · 2Los Angeles County has recorded more than 180 West Nile virus cases this year, the highest number in nearly a decade, according to the county public health department. 1 2 Left · 1The Guardian attributes the surge to a series of heatwaves, an extra-powerful El Niño, a very mild winter with heatwaves in February and March that kept mosquitoes active, and an unusually moist, humid summer. Anais Medina Diaz of the San Gabriel mosquito and vector control district linked the higher activity to the warm winter. 1

Left · 1The Guardian says a record-breaking heatwave since early October is forecast to ease, but temperatures will mostly stay too high to stop mosquito activity and coming rain will create new breeding sites. 1 Mixed · 2The region's native Culex quinquefasciatus picks up West Nile virus from birds such as crows and can then pass it to humans. In Orange County, about 850 traps have tested positive for the virus, according to the county's vector control district; its spokesperson Brian Brannon said this means 850 traps, not 850 mosquitoes. 1 2 Mixed · 2The mosquitoes residents notice most are invasive Aedes, first seen in the region in 2014 and nicknamed "ankle biters", which target humans and bite repeatedly. Aedes are not linked to West Nile but are known spreaders of dengue, chikungunya, Zika and yellow fever, and the Guardian reports fears that dengue could spread via travellers. 1 2

Left · 1Authorities remove standing water and spray adulticide in problem areas; Brannon said pre-emptive spraying is one reason West Nile cases have not exceeded 2014 numbers. Releasing X-ray-sterilised male mosquitoes has cut targeted populations by more than 80% at some experimental sites, but it is costly (about $30,000 for 25 acres in the San Gabriel Valley), works only on Aedes aegypti, and property owners have been reluctant to back tax increases to fund it. 1 Mixed · 2Both outlets quote a TikTok user with more than 20,000 likes and El Segundo resident Truman Hedding, who told Fox 11 News it was "an absolute nightmare". The Guardian advises residents to wear long sleeves and repellent containing Deet, picaridin, IR3535 or oil of lemon and eucalyptus. 1 2