BEND, Ore. - Health officials in central Oregon say they're concerned about a big jump in the number of cases of sexually transmitted diseases.

The Bulletin newspaper in Bend reports that chlamydia cases have been rising since 2010, increasing from 432 cases in Deschutes County a decade ago to 675 last year. The number of cases in Crook County has nearly doubled and the number in Jefferson is up 52 percent.

Syphilis cases are also on the rise, and gonorrhea diagnoses rose from single digits in the early part of this decade to 65 cases in Deschutes County, 49 in Jefferson and 14 in Crook County last year.

Public health officials say the evolution of HIV infection into a manageable condition has reduced the perceived risk of unprotected sex for many, allowing chlamydia, gonorrhea and syphilis to spread more rapidly. They say the emergence of dating apps for phones hasn't helped.

Still, some of the increase might be attributed to better monitoring or easier testing for the diseases.