Though there are other sexually transmitted diseases (STDs) that are more common, few have the potential to cause lasting and irreversible damage as syphilis does. Caused by the bacterium Treponema pallidum, infections of syphilis spread through skin-to-skin contact, and the disease can be transmitted even in the absence of bodily fluids like blood, semen or vaginal fluids.

Untreated syphilis can cause permanent damage to the body and can even lead to death. In fact, many famous historical figures, including mobster Al Capone and writer Oscar Wilde, are believed to have died from the STD that today is easily treated.

What does syphilis do to the body, how is it transmitted and how common is it throughout the United States? Read on to learn more about this dangerous but easily cured STD.

What Is Syphilis?

Syphilis is a bacterial infection that causes sores (also called chancres) on an infected person’s genitals (and sometimes the mouth). Syphilis is transmitted through contact with the sores of an infected person. These sores are often mistaken for other things, such as pimples or unrelated rashes, so many syphilis-infected people who do have sores don’t take extra precautions because they aren’t aware they’re at risk of passing along syphilis. In many cases, the sores are so minor that people don’t notice them at all.

When syphilis goes undiagnosed and untreated, it sometimes can develop into tertiary syphilis, which can be a terminal condition that impacts many systems of the body, including the brain, eyes, heart, blood, bones and joints. It can take as many as 30 years for primary or secondary syphilis (the two earliest stages) to turn into tertiary syphilis.

The symptoms of syphilis are largely the same between men and women with chancres appearing about three weeks after the initial infection (primary syphilis) and body rashes, fever, fatigue and other symptoms coming and going for a couple of years (secondary syphilis). Late stages of syphilis, including tertiary syphilis, affect about 1 in 3 people who go untreated.

Who Is Most Likely to Get Syphilis?

In the U.S., syphilis rates are highest among men who have sex with men, so gay and bisexual men are at the highest risk of contracting syphilis. Infection rates are highest among those between the ages of 20 and 29.

While men still have a far higher overall infection rate, the proportion of American women with syphilis has surged in recent years, rising more than 115% between 2013 and 2017.

Syphilis infection rates by sex, age 15+ (cases per 100,000 people)

Age group Males Females
15–19 10.1 3.2
20–24 41.1 7.8
25–29 51.9 7.1
30–34 39.3 5.1
35–39 30.3 4.1
40–44 20.5 2.8
45–54 17.8 1.5
55–64 7.3 0.5
65+ 1.5 0.1
Total 16.9 2.3

Among racial and ethnic groups, African-Americans are most likely to be infected with syphilis.

Syphilis infection rates by race, age 15+ (cases per 100,000 people)

African-American 24.2
Native American/Alaska Native 11.1
Native Hawaiian/Pacific Islander 13.9
Hispanic/Latino 11.8
White 5.4
Multiracial 7.9
Asian 4.4

Syphilis Across the U.S.

The national rate of syphilis infections is 9.5 per 100,000 people, but several states have rates that are many times higher than that, while others have much lower concentrations of the disease.

Syphilis infection rate by state (cases per 100,000 people)

Nevada 20
California 17.1
Louisiana 14.5
Georgia 14.4
Arizona 13.6
New York 11.9
Florida 11.6
North Carolina 11.2
Mississippi 10.4
Illinois 9.6
Maryland 9.5
Oklahoma 9.5
New Mexico 9.3
Washington 9.3
Alabama 8.7
Oregon 8.6
Missouri 8.3
Texas 8
Massachusetts 7.9
Arkansas 7.8
South Carolina 7.3
Tennessee 7.3
Ohio 7.2
Rhode Island 6.7
Hawaii 6.6
Virginia 6.4
Pennsylvania 6.2
Delaware 6
Kentucky 5.9
North Dakota 5.8
New Jersey 5.6
Colorado 5.3
Minnesota 5.3
Maine 4.9
Indiana 4.8
Michigan 4.8
Kansas 4.6
Montana 4.6
Idaho 3.8
South Dakota 3.8
Utah 3.8
West Virginia 3.4
Iowa 3.2
New Hampshire 3.2
Connecticut 3.1
Wisconsin 3
Nebraska 2.3
Vermont 2.1
Alaska 1.8
Wyoming 0.7
Total 9.5

Most states have seen their syphilis rates rise over the past few years, with a handful of states posting increases of well over 300%. Four states have seen their syphilis rates drop in that same time, though.

Percentage change in syphilis infection rates (cases per 100,000 people), 2013-2017

Alaska -42%
South Dakota -27%
Iowa -6%
Michigan -2%
Nebraska 5%
Delaware 7%
Maryland 23%
Oregon 26%
South Carolina 28%
Arkansas 30%
Georgia 41%
Texas 43%
Indiana 45%
Massachusetts 46%
Utah 46%
Minnesota 47%
Florida 51%
New Hampshire 52%
Illinois 55%
Rhode Island 56%
Louisiana 59%
New York 61%
Virginia 68%
Pennsylvania 68%
Colorado 71%
Wisconsin 76%
California 86%
Ohio 89%
Connecticut 94%
Missouri 98%
Hawaii 100%
Kentucky 111%
New Jersey 115%
Tennessee 121%
Washington 127%
Alabama 129%
New Mexico 151%
Kansas 156%
North Carolina 173%
Nevada 174%
Oklahoma 206%
Arizona 216%
North Dakota 241%
Wyoming 250%
Mississippi 300%
Vermont 320%
Idaho 322%
West Virginia 325%
Maine 513%
Montana 820%

Similar variations can be seen when looking at city-level data as when examining the differences in states’ rates of syphilis infections. Among major metro areas, Las Vegas has the highest rate of infection.

Syphilis rates by metro area (cases per 100,000 population)

Las Vegas-Henderson-Paradise, NV 24.1
San Francisco-Oakland-Hayward, CA 22
Atlanta-Sandy Springs-Roswell, GA 18.9
Los Angeles-Long Beach-Anaheim, CA 17.8
San Diego-Carlsbad, CA 17.6
Austin-Round Rock, TX 17.5
Columbus, OH 17.3
Phoenix-Mesa-Scottsdale, AZ 16.6
New Orleans-Metairie, LA 16.5
Oklahoma City, OK 15.9
Miami-Fort Lauderdale-West Palm Beach, FL 15.1
Sacramento-Roseville-Arden-Arcade, CA 14.9
Charlotte-Concord-Gastonia, NC-SC 14.3
San Antonio-New Braunfels, TX 13.5
Jacksonville, FL 13.1
Orlando-Kissimmee-Sanford, FL 13
Baltimore-Columbia-Towson, MD 12.2
New York-Newark-Jersey City, NY-NJ-PA 12.2
Chicago-Naperville-Elgin, IL-IN-WI 12
Tampa-St. Petersburg-Clearwater, FL 12
Louisville-Jefferson County, KY-IN 11.7
Seattle-Tacoma-Bellevue, WA 11.6
Memphis, TN-MS-AR 11.4
San Jose-Sunnyvale-Santa Clara, CA 11
Riverside-San Bernardino-Ontario, CA 10.9
Birmingham-Hoover, AL 10.6
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD 10.5
Portland-Vancouver-Hillsboro, OR-WA 10.5
Raleigh, NC 10.4
Washington-Arlington-Alexandria, DC-VA-MD-WV 10.4
Kansas City, MO-KS 10.2
St. Louis, MO-IL 9.9
Virginia Beach-Norfolk-Newport News, VA-NC 9.8
Dallas-Fort Worth-Arlington, TX 9.7
Richmond, VA 9.7
Indianapolis-Carmel-Anderson, IN 9.3
Cleveland-Elyria, OH 8.8
Nashville-Davidson-Murfreesboro-Franklin, TN 8.6
Boston-Cambridge-Newton, MA-NH 7.8
Denver-Aurora-Lakewood, CO 7.6
Salt Lake City, UT 7.3
Minneapolis-St. Paul-Bloomington, MN-WI 7
Detroit-Warren-Dearborn, MI 6.8
Providence-Warwick, RI-MA 6.1
Houston-The Woodlands-Sugar Land, TX 5.7
Buffalo-Cheektowaga-Niagara Falls, NY 5.3
Milwaukee-Waukesha-West Allis, WI 5
Cincinnati, OH-KY-IN 4.8
Pittsburgh, PA 3
Hartford-West Hartford-East Hartford, CT 2.7

Syphilis is far less common in the U.S. today than in decades past, but the ground that has been gained against the disease since the middle of the last century are beginning to shrink as the national rate keeps climbing. Since its lowest recorded level (2005), the syphilis rate has risen by 180%, and today’s level is approaching the levels seen 30 years ago. Still, the syphilis infection rate has dropped by more than 90% from the highs the U.S. posted in the 1940s.

Syphilis rates by year (cases per 100,000 population)

1984 29.6
1985 28.4
1986 28.2
1987 36
1988 42.8
1989 46.6
1990 54.3
1991 50.9
1992 44.7
1993 39.5
1994 31.4
1995 26
1996 19.8
1997 17.1
1998 13.9
1999 12.7
2000 11.2
2001 11.3
2002 11.4
2003 11.8
2004 11.4
2005 11.2
2006 12.3
2007 13.6
2008 15.2
2009 14.6
2010 14.8
2011 14.8
2012 15.9
2013 17.9
2014 19.9
2015 23.2
2016 27.3
2017 31.4

Conclusion

While syphilis remains relatively rare among all STDs, it still is one of the most potent and dangerous common sexually transmitted infections. With the power to cause permanent damage to crucial body systems, even causing death, syphilis is nothing to take lightly.

The prevalence of antibiotics should largely be credited with dramatic drops in the rate of syphilis over the past 70 years, but the resurgence of syphilis is certainly a cause for great concern, particularly given the potential for this disease to wreak havoc on the body. Over the course of just four years (2014-2017), the syphilis rate jumped 57%.

Syphilis is much less common than some other STDs that have been shown to impact most sexually active people, but the risks involved in untreated syphilis are too high to be casual about finding out your status. For many infected people, syphilis can be cleared up with a single injection of medicine.

Additional References

Centers for Disease Control and Prevention, Syphilis - CDC Fact Sheet (Detailed). (2017). Retrieved from https://www.cdc.gov/std/syphilis/stdfact-syphilis-detailed.htm

Centers for Disease Control and Prevention, Table 34. Primary and Secondary Syphilis — Reported Cases and Rates of Reported Cases by Age Group and Sex, United States, 2013–2017. Retrieved from https://www.cdc.gov/std/stats17/tables/34.htm

Centers for Disease Control and Prevention, Table 35B. Primary and Secondary Syphilis — Rates of Reported Cases per 100,000 Population by Race/Hispanic Ethnicity, Age Group, and Sex, United States, 2017. (2018). Retrieved from https://www.cdc.gov/std/stats17/tables/35b.htm

Centers for Disease Control and Prevention, Table 30. Primary and Secondary Syphilis — Reported Cases and Rates of Reported Cases in Selected Metropolitan Statistical Areas (MSAs)* in Alphabetical Order, United States, 2013–2017. (2018). Retrieved from https://www.cdc.gov/std/stats17/tables/30.htm

Centers for Disease Control and Prevention, Table 1. Sexually Transmitted Diseases — Reported Cases and Rates of Reported Cases per 100,000 Population, United States, 1941–2017. (2018). Retrieved from https://www.cdc.gov/std/stats17/tables/1.htm