The West Nile Virus has made its way to the South County.

On Thursday the San Joaquin Mosquito and Vector Control District will step up spraying efforts after traces of the virus, which already claimed the life of one county resident this year, appeared in samples taken from a trap in rural South Manteca.

Warm temperatures have helped create an environment in which mosquito larvae – which can hatch in just a few inches of water – thrive, and local health officials are trying to stay on top of controlling the adult populations as Mother Nature’s last warm streak of the summer plows through the Central Valley.

According to district spokesman Aaron Devencenzi, two adult mosquitoes that were taken from a trap near the confluence of the San Joaquin and Stanislaus Rivers last week tested positive for the West Nile Virus. The location is about six miles south of Manteca and six miles west of Ripon. It’s the first time this year that traces of the disease have stretched beyond Stockton this year. It has prompted county officials to look at expanding the borders upon which they’re conducting spraying efforts.

The first reported case came earlier in the summer when a 52-year-old man donating blood tested positive. He was asymptomatic. An 83-year-old woman died earlier this month from complications stemming from contracting the virus. Young children, seniors and people with compromised immune systems are all a higher risk level than normal healthy adults to develop symptoms associated with the blood-borne illness.

Thursday won’t be the first time that the district has sprayed portions of rural South Manteca and areas outside of Ripon, but it will be the first time that they’ll extend the areas they’re covering as far north as Perrin Road (Airport Road) and as far east as Austin Road.

A section of Ripon that will extend from the sewer plant near the intersection of Stockton Avenue and Doak Boulevard out to the Stanislaus County line will also represent an expansion of territory being covered.

“We want to make sure that we keep the populations in check as best we can so that we can limit the spread of West Nile Virus,” Devencenzi said. “It’s important in making sure that people don’t contract the virus.”

On Monday the district sprayed a portion of Manteca that stretched from Wawona Street west to Airport Way, south to the Highway 120 bypass and east to South Union Road.

According to a schedule released by the agency, ground spraying for adult mosquitoes is being completed using Evergreen 60-6 and/or Fyfanon ULV – a pesticide widely-used in agriculture and approved for a use on a variety of crops.

So far aerial spraying has not been a viable option for the district this year.