This report will be used by the U.S. Preventive Services Task Force (USPSTF) to update its 2005 recommendation on screening for gonorrhea and its 2007 recommendation on screening for chlamydia. Gonorrhea is an STI caused by the bacterium Neisseria gonorrhoeae, a gram-negative intracellular diplococcus that infects the mucosal epithelium of the genital tract. Other sites of infection include the conjunctiva, oropharynx, and rectum. Infection with N. gonorrhoeae often leads to local inflammation and, in women, can ascend the urogenital tract and cause pelvic inflammatory disease (PID). Infants born to infected mothers may contract gonococcal eye disease in the first few days of life. Chlamydia is an STI caused by the bacterium Chlamydia trachomatis. Most C. trachomatis strains infect the epithelial cells of the genital tract, causing inflammation that may be asymptomatic or present as erythema, edema, and mucopurulent discharge. Infections of the rectum can cause proctitis, while infections of the oropharynx are typically asymptomatic. Inflammation damages the epithelium and leads to scar formation. In women, scarring may ultimately lead to fallopian tube occlusion and infertility years after active infection. Infants born to infected mothers may contract chlamydial eye disease and pneumonia. In 2005, the USPSTF issued a recommendation to screen for gonorrhea in all sexually active women at increased risk for infection, including pregnant women. Women at increased risk include those who are younger than age 25 years; live in high prevalence communities; have a history of gonococcal infection or other sexually transmitted infections (STIs); have new or multiple sex partners; or engage in inconsistent condom use, sex work, or drug use. The USPSTF recommended against routine screening in men and nonpregnant women at low risk for infection, and found insufficient evidence to recommend for or against routine screening in high-risk men and low-risk pregnant women. In 2007, the USPSTF issued a recommendation to screen for chlamydia in all sexually active nonpregnant women younger than age 25 years and in older high-risk nonpregnant women (i.e., those who have a history of chlamydial infection or other STIs, have new or multiple sex partners, or engage in inconsistent condom use or sex work). The age specification for screening in the 2007 recommendation differed from the previous recommendation (25 years or younger) in order to align with evidence on screening, including national surveillance data from the Centers for Disease Control and Prevention (CDC). The USPSTF also recommended screening in pregnant women younger than age 25 years and in older high-risk pregnant women, and recommended against routine screening in low-risk women age 25 years or older regardless of pregnancy status. The USPSTF found insufficient evidence to recommend for or against routine screening in men.