Chlamydia is the most common bacterial infection; HPV is the highest viral infection. HPV has a higher incidence rate than chlamydia. <br /><br /> Human Papilloma Virus (HPV) infection is the most common sexually transmitted disease/sexually transmitted infection (STD/STI) in the United States today. Herpes-Simplex Virus-2 (HSV-2) is the second most common. The most common bacterial STDs are Chlamydia and Gonorrhea, but overall, HPV and HSV are far more common.