Recent study revealed that the number of U.S. women ages 16-25 screened for chlamydia has increased from 25 percent to 43 percent during 2000-2006. Research team at the U.S. Centers for Disease Control and Prevention reported that there are still far too few women being screened. 

Researchers wrote in the report that Chlamydia trachomatis infection is the most common bacterial sexually transmitted disease (STD) in the United States, with more than 2.8 million new cases estimated to occur each year. 

Chlamydia can lead to pelvic inflammatory disease, infertility, chronic pain and ectopic pregnancy, which is a pregnancy outside the uterus, if not treated with antibiotics. It often causes few or no symptoms. Chlamydia can be passed to a newborn and can cause pneumonia and conjunctivitis, or pink eye. Both men and women can be infected by this sexually communicated disease.

Research team led by Dr. Karen Hoover studied the records of public and private health plans representing more than 40 percent of the U.S. population for the study.

Researchers said: "During 2007, approximately 1.1 million cases of chlamydia were reported to CDC; more than half of these were in females aged 15 to 25 years."