untreated std for years :: Article Creator GROSS: Top Ranking Cities For Sexually Transmitted Diseases (STD ... Want to know the most common sexually transmitted disease (STD) in your city? You might be surprised by the results. Find your city in the gallery below. Want to know the most common sexually transmuted disease (STD) in your city? You might be surprised by the results. Fusion, using data from the Center of Disease Control, found the top ranking cities for some of the most widespread STDs, including chlamydia, gonorrhea, syphilis, and HIV. Chlamydia Top ranked cities: #1 Memphis, Tenn. #2 Anchorage, Alaska. #3 Philadelphia, Penn. Chlamydia is the most common STD in the United States with more than 1.4 million cases reported in 2013. Most people with chlamydia never show symptoms, or not until months or years after infection. If untreated, chlamydia can cause pelvic inflammatory disease in women, severely damaging the reproduct...