Maryland frequently ranks among the U.S. states with the highest prevalence of sexually transmitted diseases (STDs), such as chlamydia, gonorrhea, syphilis and others. And the frequency of STDs in Maryland, like much of the rest of the U.S., is on the rise for many types of sexually transmitted infections.

Which STDs are the most common here in Maryland, how has the prevalence of certain diseases changed over time, and which locales in the state have the highest rates of STDs? To understand the picture of sexual health in Maryland, we’ll dig into data from the federal Centers for Disease Control and Prevention and the Maryland Department of Health.

Chlamydia Rates in Maryland

Maryland ranks just outside the top 10 when it comes to the population-adjusted rate of chlamydia, and more than 30,000 people in Maryland were diagnosed with chlamydia in 2018. The rate of chlamydia infections in Maryland is about 10% higher than the national rate.

Chlamydia infections per 100,000 people

Highest
Alaska 799.8
Louisiana 742.4
Mississippi 707.6
New Mexico 651.6
South Carolina 649.8
Georgia 623.7
Alabama 615.5
North Carolina 612.2
New York 591.6
Illinois 589.9
Maryland 586.3
Total 528.8
Lowest
Minnesota 426.4
Massachusetts 425.7
New Jersey 392
Idaho 368.4
Wyoming 365.8
Maine 342.1
Utah 332.2
New Hampshire 330.5
Vermont 297.5
West Virginia 226.1

Maryland’s rate of chlamydia had remained relatively steady for a few years, but it’s gone up every year since 2014 and increased by more than one-third between 2008 and 2018.

Maryland chlamydia rate by year (cases per 100,000 people)

2008 437.9
2009 416.7
2010 453.7
2011 466.9
2012 450.9
2013 450.7
2014 458.9
2015 457
2016 509.6
2017 552.1
2018 586.3

Six of the 10 states with the highest rates of chlamydia are in the South, and Maryland’s rate places the state in the top half regionally.

Chlamydia infection rate, Southern states (cases per 100,000 people)

Louisiana 742.4
Mississippi 707.6
South Carolina 649.8
Georgia 623.7
Alabama 615.5
North Carolina 612.2
Maryland 586.3
Arkansas 579.6
Delaware 566.3
Oklahoma 554.4
Texas 543.9
Tennessee 522.5
Virginia 488.3
Florida 485.2
Kentucky 435.4
West Virginia 226.1

 Gonorrhea Rates in Maryland

Maryland’s population-adjusted rate of gonorrhea infections is slightly below the national rate, but the state ranks in the top half among all states.

Gonorrhea infections per 100,000 people, top 25

Mississippi 309.8
Alaska 295.1
Louisiana 256.7
South Carolina 254.4
Alabama 245.7
Oklahoma 231.4
Arkansas 224.5
North Carolina 220.9
Georgia 217.5
Ohio 216.3
New Mexico 215.7
Missouri 214.8
California 192
Nevada 187.8
Delaware 187.4
Illinois 186.4
Tennessee 185
Arizona 180.5
Indiana 177.5
New York 172.7
Maryland 170.3
Texas 170.2
Kentucky 167.2
Kansas 156.3
Michigan 154.7
Total 171.9

Bucking national trends, gonorrhea has become less prevalent in Maryland over the past year, but the disease still has seen a huge increase in the past decade, with the rate increasing almost 44% between 2008 and 2018.

Maryland gonorrhea rate by year (cases per 100,000 people)

2008 118.3
2009 112.2
2010 128.4
2011 110.8
2012 96.6
2013 101
2014 102.2
2015 114.2
2016 158.3
2017 181.4
2018 170.3

Thanks in part to the one-year decline in gonorrhea, Maryland ranks in the bottom half of the Southern region with a rate that’s just under half that of the region’s leader, Mississippi.

Gonorrhea infection rate, Southern states (cases per 100,000 people)

Mississippi 309.8
Louisiana 256.7
South Carolina 254.4
Alabama 245.7
Oklahoma 231.4
Arkansas 224.5
North Carolina 220.9
Georgia 217.5
Delaware 187.4
Tennessee 185
Maryland 170.3
Texas 170.2
Kentucky 167.2
Florida 153.7
Virginia 143.3
West Virginia 70.8

Syphilis Rates in Maryland

Maryland has the sixth-highest population-adjusted rate of primary and secondary syphilis infections in the country with a rate that’s more than 25% higher than the overall U.S. rate.

Primary and secondary syphilis infections per 100,000 people

Highest
Nevada 20
California 17.1
Georgia 14.5
Louisiana 14.5
Arizona 13.1
Maryland 12.2
New York 11.9
Florida 11.6
North Carolina 10.6
Mississippi 10.4
Total 9.5
Lowest
Idaho 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

The rate of primary and secondary syphilis infections in Maryland has gone up every year since 2012 and over the past decade, the rate has nearly doubled.

Maryland primary and secondary syphilis rate by year (cases per 100,000 people)

2008 6.7
2009 5.5
2010 5.7
2011 7.8
2012 7.3
2013 7.7
2014 7.5
2015 8.5
2016 8.5
2017 9.5
2018 12.2

Southern states make up 60% of the 10 states with the highest syphilis rates, and Maryland is third overall in the region.

Primary and secondary syphilis infection rates, Southern states (cases per 100,000 people)

Georgia 14.5
Louisiana 14.5
Maryland 12.2
Florida 11.6
North Carolina 10.6
Mississippi 10.4
Oklahoma 9.5
Alabama 8.7
Texas 8
Arkansas 7.8
Tennessee 7.3
South Carolina 7.3
Virginia 6
Delaware 6
Kentucky 5.9
West Virginia 3.4

HIV & Other STD Rates in Maryland

HIV

More than 1,000 people were newly diagnosed with HIV in Maryland in 2017, and the state’s population-adjusted rate is the fourth-highest in the country. But in a bit of good news, Maryland posted a nearly 10% decrease in HIV prevalence between 2016 and 2017. See HIV test options.

Hepatitis B & C

Acute infections of both hepatitis B and hepatitis C are lower in Maryland than the rest of the country, and hep B infections have declined dramatically in recent years. Acute hep B cases dropped by more than 50% between 2012 and 2016, while acute hep C infections fell by about 14% in the same time period. See hepatitis test options.

HPV

In addition to being the most common STD in the world, human papillomavirus also causes the vast majority of several types of cancer, including cancers of the cervix, penis, anus and vulva. Pinpointing how many people at any given time have HPV is quite difficult because most cases do not cause any obvious symptoms, but understanding the rate of HPV-causes cancer can paint at least part of the picture. Maryland’s rate of HPV-caused cancer is about 8% lower than the national median, and Maryland’s rate is the nation’s 11th-lowest. See HPV test options.

STDs in Maryland Cities & Counties

Cases of chlamydia, gonorrhea, and primary and secondary syphilis are much more common in Baltimore than in the rest of the state, and the city makes up a huge percentage of cases of all three STDs, though a few other areas of the state also have higher rates of certain diseases.

Chlamydia

Baltimore County and the city of Baltimore combined to account for more than one-third of all infections of primary and secondary syphilis in Maryland in 2017.

Maryland counties by chlamydia infection rate (cases per 100,000 people), top 10

Baltimore City 1,248.4
Prince George's 806.8
Somerset 713.8
Charles 631.8
Wicomico 627.7
Dorchester 572.1
Baltimore County 538.2
Worcester 415.9
Washington 391.8
Anne Arundel 389.7

Gonorrhea

About 2 in 5 gonorrhea infections in Maryland in 2017 were diagnosed in people living in the city of Baltimore.

Maryland counties by gonorrhea infection rate (cases per 100,000 people), top 10

Baltimore City 691.70
Wicomico 291.5
Prince George's 219.2
Somerset 216.1
Dorchester 211.4
Baltimore County 186.1
Charles 149.7
Caroline 123.5
Washington 120.2
Worcester 106.4

Primary and secondary syphilis

The city of Baltimore and Baltimore County combined to account for nearly half of all syphilis infections in 2017.

Maryland counties by primary and secondary syphilis infection rate (cases per 100,000 people)

Baltimore City 34.3
Prince George's 15.7
Baltimore County 8.9
Calvert 6.6
Anne Arundel 5.9
Charles 5.6
Kent 5.2
Montgomery 5
Howard 4.7
Washington 4

Conclusion

Maryland ranks relatively highly when it comes to how common sexually transmitted disease are in our state. But as the decline in the prevalence of both gonorrhea and HIV shows, it’s possible to make progress against such infections. Getting yourself tested to make sure you aren’t unknowingly passing along a sexually transmitted infection is a smart first step.

Additional References

Note: Some states have published more recent data for chlamydia, gonorrhea, and primary and secondary syphilis. For states in which that’s the case, we have substituted the individual state data for 2018 and used that in our rankings, while other states’ rankings are based on 2017 numbers. In some cases, we assume that when the full national dataset that includes 2018 is published by the CDC, states’ positions relative to other states will change, though those changes are unlikely to be dramatic, since the CDC data comes from the states.