STD Quarterly

Snapshot: New trends in STDs in the U.S.

What are some emerging trends in other sexually transmitted diseases (STDs) in the United States? Check the following highlights from the Atlanta-based Centers for Disease Control and Prevention’s (CDC) 2003 STD Surveillance Report:

  • Chlamydia.

Chlamydia retains its No. 1 status as the most commonly reported infectious disease in the United States. In 2003, 877,478 chlamydial infections were reported, an increase from 2002’s 834,555 case level. The CDC estimates there are actually 2.8 million new cases of chlamydia each year, since many cases are not reported or diagnosed.1

  • Syphilis.

The syphilis rate in the United States rose for the third consecutive year in 2003 and increased 19% from its all-time low in 2000. The national rate of primary and secondary (P&S) syphilis increased by 4.2% from 2002 to 2003, from 2.4 to 2.5 cases per 100,000 population.

What is fueling this rise? Outbreaks of syphilis among men who have sex with men (MSM) have been reported in several U.S. cities in recent years, and they may be a major factor in increasing the national syphilis rate. Recent research indicates more than 60% of all P&S cases reported in 2003 occurred among the MSM population.2


1. Weinstock H, Berman S, Cates W. Sexually transmitted diseases among American youth: Incidence and prevalence estimates, 2000. Perspect Sex Reprod Health 2004; 36:6-10.

2. Heffelfinger J. Estimates of the numbers of cases of primary and secondary syphilis occurring among men who have sex with men in the United States, 1999-2002. Presented at the 2004 National STD Prevention Conference. Philadelphia; March 2004.