By Lynne Adkins

PHILADELPHIA (CBS) – Pennsylvania officials are warning residents that the number of cases of West Nile Virus will continue to climb as we enter prime mosquito season. So far, there are a dozen known cases and at least one death in Pennsylvania.

Prime mosquito time is late August thru early fall according to Deborah Fries, the local Community Relations Supervisor for the Pennsylvania Department of Environmental Protection.

She says those bugs could make a lot of people sick with West Nile Virus.

“Statewide the DEP is tracking very high levels of the virus in mosquito populations. Right now the infection rates in the mosquito populations are three to four times higher than what we have been experiencing.”

Officials believe the warm winter and spring may have helped more insects to survive and arrive early.

Fries says spraying will continue and area residents can help by dumping standing water and remaining indoors at dusk and dawn, which is when mosquitoes are out looking for victims.