Chlamydia trachomatis has become the most common sexually transmitted infection in the United States. Aggressive screening of sexually active young adults is needed, as well as prompt and reliable treatment of infected partners, to mitigate the effects of this disease. Tests using enzyme immunoassay and DNA probe have increased the efficiency of diagnosis through rapid detection, although culture remains the most reliable test. Treatment with single-dose azithromycin is a successful alternative to the definitive treatment, seven days of doxycycline therapy.