Fewer than 40 percent of sexually active young U.S. women were screened for chlamydia in the previous year, federal health officials said. The Centers for Disease Control and Prevention in Atlanta recommends annual screening for all sexually active women age 25 and under. Dr. Kevin Fenton, director of the CDC's National Center for HIV/AIDS, Viral Hepatitis, Sexually Transmitted Diseases and Tuberculous Prevention, and colleagues analyzed self-reported data on chlamydia testing among teenage girls and young women ages 15-25 from the National Survey of Family Growth. The study found overall testing rates remain low, although testing was most common among African-American women, those who had multiple sex partners and those who received public insurance or were uninsured. Fenton said this was encouraging because these are some of the groups at highest risk for chlamydia. The CDC recommends anyone diagnosed with chlamydia be retested three months after initial treatment to ensure that those who may have become reinfected can be promptly treated with antibiotics. However, additional data showed retesting rates remained low and many reinfections likely are being missed. The findings were presented at the National STD Prevention Conference in Minneapolis.