Eight tick samples in Placer County have tested positive for the Lyme disease organism in the past two weeks.
Placer County's Mosquito and Vector Control District says there has been an increase in the tick population since the late fall, and ticks are capable of infecting humans with the Lyme disease pathogen in summer or winter months.
The District advises people working or playing outdoors to wear long sleeves and long pants.
California's Department of Public Health issued a tick advisory last week.
