The Daily Mail had it:
http://www.cdc.gov/nchhstp/newsroom/2015/std-surveillance-report-press-release.html
From the CDC document:
In 2014, rates of P&S syphilis increased among MSM, who account for 83 percent of reported cases among men when the sex of the partner is known.
P&S=Primary and secondary
MSM=Men who have sex with men
In other words, this is overwhelmingly a problem associated with homosexual men, not just "men."
The huge difference between the infection numbers for homosexual men and straight men (and women) is shown in a politically incorrect chart in this fact sheet: http://www.cdc.gov/nchhstp/newsroom/docs/factsheets/std-trends-508.pdf
Unfortunately I can't hotlink the chart.
The Daily Mail had it: