Warming Climate May Cause More West Nile Outbreaks in Southern California

Coastal populations from San Diego to Santa Barbara may be at increased risk of West Nile virus and other mosquito-borne diseases as climate change makes Southern California hotter, researchers from the University of California, Berkeley say. New research led by us suggests.

The West Nile virus, the most deadly mosquito-borne disease in America, has been a threat to the Los Angeles metropolitan area since its arrival in 2003. The virus infects mosquitoes and birds and spreads to humans by being bitten by infected mosquitoes.

The research team analyzed data on nearly two million mosquitoes caught and tested in the West Nile River in Los Angeles between 2006 and 2016. Then use machine learning with landscapes Climatic conditions Infected mosquitoes in different areas.

They found that the transmission between caught mosquitoes was strongly associated with the average temperature in the neighborhood.

“Our data reveals dramatic changes in the likelihood of catching infected mosquitoes near Los Angeles as temperatures change between 70 and about 73 degrees Fahrenheit,” the University of California. Environmental health sciences at Berkeley School of Public Health. “Beyond this range, the condition is always favorable for transmission, below this range the condition is always unfavorable.

Results announced today in the journal Minutes of the Royal Society BTo explain why the typical coastal LA community, to the right of which summer conditions are to the right at the border of good and restraining temperatures, has been protected for some years but vulnerable elsewhere. Useful

Justin Remais, associate professor of environmental health sciences at the University of California, Berkeley, expects significant warming over the next few decades, with more West Nile cases on the coast of Southern California. I said yes.

“Coastal LA appears to be vulnerable to the climate warming of California expected by the mid-20th century, which will push the coastal climate into a more consistent and favorable zone,” Remais said. “Inland LA may be less susceptible to these changes as the climate is already good, but as climate warming moves towards the end of the century, temperatures heat up in these regions. It may be too much.”

Researchers emphasize that the risk of infection does not appear to increase significantly, especially on hot days or days. Rather, it’s a warm temperature that lasts for weeks mosquito Time to acquire an infection and pass it on to a host species of birds such as house finch.

“Our research suggests that it’s important to look at long-term temperatures rather than focusing on daily weather forecasts,” Scuff said. “If the coast of Los Angeles experiences warm temperatures of one or two months in summer or early fall, it’s probably a good time to be especially careful not to be bitten by mosquitoes. The inland part of LA is mostly during the summer. If it’s hot enough then other factors will determine if a severe infection will occur there.

The data also show that temperature plays a very important role, but researchers emphasize that many factors ultimately determine whether West Nile outbreaks occur.

“You can think of an advantage temperature “The range we have identified as a prerequisite may still not occur if something else goes wrong for the vector or virus, even at good temperatures,” Skuff said. Due to a large outbreak, the area became infected the previous year or two years, making the herd more immune and limiting the risk to people. “

“Predicting the transmission of infectious diseases mediated by animal hosts and vectors means a complex puzzle,” Remais added, and “machine learning puts certain people or regions at the highest risk. You can pick up a huge pattern of epidemiological and ecological datasets that can help you understand why, and what the future holds.”