SYRACUSE - Health officials here say efforts to curb the sexually transmitted disease chlamydia appear to be having an effect in Onondaga County, where reported cases had risen 60 percent between 2002 and 2004, according to a published report Friday.

The disease's prevalence prompted the state to set up “sentinel sites” in Onondaga, Monroe, Westchester, Erie and Dutchess counties in 2003.

Those counties have increased screening, testing every patient who walks through the doors of their sexually transmitted disease clinics.

Diane Rothermel, director of the Onondaga County Bureau of Disease Control, said the number of new infections appears to be down about 12 percent this year because of increased screening, awareness and education for both patients and doctors.

Chlamydia often has no symptoms. Usually, people come to the clinics worried they have another sexually transmitted disease, such as syphilis or gonorrhea.

“Because it is silent and it often goes undiagnosed, people pass it to partners who pass it on and on and on,” Rothermel told the newspaper.