Virus is confirmed in region

The San Gabriel River is also a trouble spot, he added.

The district has been actively treating the backyard pools, which Wassem said has helped to keep things under control, particularly considering the increase in foreclosures and a general uptick in residents unwilling to refill and maintain swimming pools given the water-supply problems, rationing measures and increased utility rates.

Murky swimming pools across Burbank and Glendale, which this spring rose between 10% and 15% over the same period last year, create ideal breeding grounds for disease-carrying mosquitoes. So does stagnant water found on rooftops of commercial buildings and in abandoned construction sites.

Burbank’s first recorded mosquito sample — down from eight last year along with three dead birds — could easily reach into Glendale as the risk for contraction is spread evenly throughout the county, officials said. The Elmwood neighborhood trap, one of three monitored by the district, is just a few blocks from the Burbank-Glendale border.

Although code enforcement personnel in both cities monitor problem-causing areas such as green pools and other sources of standing water, residents must be vigilant, said Sam Engel, Glendale’s neighborhood services administrator.

“People are aware of the issues with standing water, whereas if you were to talk to people 20 years ago they would not have had an awareness,” he said. “Where I think the whole situation has changed is the change in the real estate market and the number of abandoned homes and foreclosures. A number of properties have pools, decorative fountains or ponds. If they’re not maintained or drained they become breeding grounds.”

County health statistics historically show about one in 10 housing structures in the area to be home to mosquito breeding. Vector control officials are asking residents to dump standing water from around their homes, wear insect repellent with DEET and long-sleeved shirts, especially at dawn or dusk.