Health officials have declared a syphilis outbreak in the Las Vegas area.
The Southern Nevada Health District said Wednesday that Clark County has had a 128 percent increase in reported syphilis cases since 2012.
Officials said 615 of the 694 cases involved men being diagnosed in 2015.
This marks Nevada as having the highest rates of syphilis in the West.
Officials are now urging people to get tested for the treatable disease, which left alone could affect internal organs and cause neurological problems, as well as increase the risks of HIV transmission.
The health agency also cited statistics from the Centers for Disease Control and Prevention that showed a huge increase in syphilis cases across the country, from about 6,000 in 2000 nearly to 20,000 cases in 2014.
