The rate of primary and secondary syphilis in the United States is continuing its steady climb, with men who have sex with men (MSM) driving a 10 percent increase between 2012 and 2013, MedPage Today reports. All told, the rates of syphilis, gonorrhea and chlamydia are all rising among men while either remaining stable or dropping among women.  These statistics are included in the Centers for Disease Control and Prevention’s (CDC) annual report, Sexually Transmitted Disease Surveillance, which provides 2013 data on various STDs.

The CDC estimates that the United States sees almost 20 million cases of STDs each year, with half of them among young people ages 15 to 24. The price tag? Nearly $16 billion in health care costs.

Since STDs are often not reported to the CDC, the figures on specific STDs do not paint a full portrait of the various nationwide epidemics. They can, however, give a sense of the rate of change in new infections.

There were 1.4 million reported cases of chlamydia reported in 2013, for a rate of 446 per 100,000 people, which is a decrease of 1.5 percent since 2012. The chalmydia rate has not dropped since national reporting on the infection began.  A total of 333,000 reported cases of gonorrhea mean a rate of 106 per 100,000 people, which was essentially stable compared to 2012.

With 17,375 cases reported in 2013, primary and secondary syphilis had a rate of 5.5 per 100,000 people, a 10 percent increase compared with 2012. This represents the highest rate of increase since 1985. The increase was driven entirely by MSM, who accounted for about three quarters of the total number of cases in 2013. An estimated half of MSM with syphilis are HIV positive. This is of particular significance considering that syphilis can increase the likelihood of both transmitting and contracting HIV.

To read the CDC fact sheet, click here.

To read the surveillance report, click here.

To read the MedPage Today report, click here.