Syphilis Material Fact Sheet

Syphilis is caused by the intracellular Gram-negative spirochete bacterium Treponema pallidum subspecies pallidum. In 2014, the total case counts and rates for syphilis in the United States were the highest recorded since 1995. The total number of cases of syphilis reported to CDC increased 12.3% during 2013–2014 (from 56,482 cases to 63,450 cases).