Rising rates of chlamydia, the most common sexually transmitted disease in the country, have health care providers more vigilant than ever in screening those most at risk. “It’s part of our routine” to offer chlamydia screenings to all women ages 16 to 24, said Dr. Alix Pose, quality assurance director at Optimus Healthcare. The company operates health clinics throughout Bridgeport, at several Stamford locations and in Stratford. Optimus doctors are increasingly urging women to be screened for chlamydia at their annual gynecological exams, Pose said. About 66 percent of their patients ages 16 to 24 are currently screened.