(HealthDay)—Syphilis rates among men who have sex with men (MSM) have increased significantly in the past two decades, according to research published in the April 7 issue of the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.

The report, which looked at syphilis rates in 44 states, was led by Alex de Voux, Ph.D., of the CDC's Epidemic Intelligence Service.

The researchers found that syphilis rates among MSM ranged widely among the 44 states—from 73.1 per 100,000 in Alaska to 748.3 per 100,000 in North Carolina. The highest rates were in the South and West.

In 2015, MSM accounted for 60.8 percent of early-stage syphilis cases overall. The national rate of early-stage syphilis for this group was estimated to be at 309 cases per 100,000. That rate was 106.0 times higher than the rate among and 167.5 times higher than the rate among women, according to the authors.

More information: Abstract/Full Text

Journal information: Morbidity and Mortality Weekly Report