Sexually transmitted diseases and infections are becoming more common across the United States. In fact, according to the federal Centers for Disease Control and Prevention, rates of several diseases, including chlamydia, gonorrhea, and primary and secondary syphilis, have risen in the U.S. for the past four straight years. How does the state of Wyoming impact those national rates?

Which STDs are most common here in Wyoming, how does our state stack up with the 49 others, how have STD rates changed in Wyoming over time, and which areas of the states are most prone to sexually transmitted diseases? To answer all those questions, we’ll dive into data from the CDC and the Wyoming Department of Health.

Chlamydia Rates in Wyoming

More than 2,000 people in Wyoming were diagnosed with chlamydia in 2018, which puts the state’s population-adjusted rate at 372.1, or seventh-lowest in the nation. Wyoming’s rate is nearly 30% lower than the overall U.S. rate and is less than half the rate posted by Alaska, which leads the nation.

Chlamydia infections per 100,000 people

Highest
Alaska 799.8
Louisiana 742.4
Mississippi 708.7
South Carolina 649.8
New Mexico 645
Georgia 623.7
Alabama 615.5
North Carolina 612.2
New York 591.6
Illinois 589.9
Total 528.8
Lowest
North Dakota 432.5
Massachusetts 425.7
New Jersey 392
Wyoming 372.1
Idaho 368.4
Maine 342.1
New Hampshire 330.5
Utah 323.7
Vermont 297.5
West Virginia 226.1

After a couple of years of declines in 2013 and 2014, the chlamydia rate has been on a slow rise in Wyoming over the past few years, climbing by about 8% between 2013 and 2018.

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

2012 364.7
2013 344.1
2014 337.6
2015 347.5
2016 351.5
2017 365.2
2018 372.1

Two Western states are among the 10 with the highest chlamydia rates, including nation-leading Alaska. Four other Western states have rates higher than the overall U.S. rate — Arizona, California, Nevada and New Mexico. Wyoming has the region’s third-lowest rate.

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

Alaska 799.8
New Mexico 645
Arizona 571.8
California 557.4
Nevada 544.7
Colorado 481.3
Hawaii 479.5
Oregon 450
Washington 444
Montana 437.4
Wyoming 372.1
Idaho 368.4
Utah 323.7

Gonorrhea Rates in Wyoming

Gonorrhea infections occur in Wyoming at a population-adjusted rate of 58.6 per 100,000 people, low enough to put the state at No. 47 overall. Wyoming’s rate is far lower than both the overall U.S. rate (-69%) and the rate of the No. 1 state, Mississippi (-83%).

Gonorrhea infections per 100,000 people

Highest
Mississippi 310
Alaska 295.1
Louisiana 256.7
South Carolina 254.4
Alabama 245.7
Oklahoma 231.4
Arkansas 223.5
North Carolina 220.9
Georgia 217.5
Ohio 216.3
Total 171.9
Lowest
Rhode Island 102.9
Hawaii 95.1
Utah 81.2
Montana 75
West Virginia 70.8
Idaho 58.6
Wyoming 53.7
Maine 46.6
New Hampshire 38.4
Vermont 32.5

The gonorrhea rate in Wyoming had seen steady increases since 2012, but 2018 marked a drop in the rate. Still, today the rate stands at more than 600% higher than it was in 2012.

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

2012 7.6
2013 11.3
2014 19.9
2015 29.9
2016 46.9
2017 71.2
2018 53.7

Alaska is the only Western state among the top 10, but four other states have rates that exceed the overall U.S. rate. Wyoming posted the lowest rate in the region.

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

Alaska 295.1
New Mexico 214
California 192
Nevada 184.9
Arizona 180.5
Colorado 151.1
Washington 137.1
Oregon 121.3
Hawaii 95.1
Utah 81.2
Montana 75
Idaho 58.6
Wyoming 53.7

Syphilis Rates in Wyoming

Wyoming’s rate of primary and secondary syphilis infections is the lowest in the nation, according to 2017 data. While the state has released 2018 data for chlamydia, gonorrhea and syphilis, those figures include all stages of syphilis and is not limited to primary and secondary syphilis, so comparing those rates to the rest of the country would be an apples-to-oranges comparison.

Primary and secondary syphilis infections per 100,000 people

Highest
Nevada 19.7
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
Total 9.5
Lowest
Idaho 3.8
Utah 3.7
West Virginia 3.4
New Hampshire 3.2
Connecticut 3.1
Wisconsin 3
Iowa 2.7
Nebraska 2.3
Vermont 2.1
Wyoming 0.7

Wyoming’s primary and secondary syphilis rate has varied quite dramatically over the past several years, and the 2017 rate is identical to the 2012 rate.

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

2012 0.7
2013 0.2
2014 0.7
2015 0.9
2016 1.2
2017 0.7

* Wyoming has released 2018 figures on syphilis rates, but the figures include all syphilis cases, not just primary and secondary syphilis, so we have not included the 2018 number here.

Three states in the region are among the 10 with the highest primary and secondary syphilis rates, but those are the only three with rates higher than the overall national rate. Wyoming’s rate is a mere fraction of the rate Nevada posted.

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

Nevada 19.7
California 17.1
Arizona 13.1
New Mexico 9.2
Washington 9.2
Oregon 8.6
Alaska 7.6
Hawaii 6.6
Colorado 5.2
Montana 4.6
Idaho 3.8
Utah 3.7
Wyoming 0.7

HIV & Other STD Rates in Wyoming

HIV

Less than a dozen people were newly diagnosed with HIV in Wyoming in 2017, making the population-adjusted rate the lowest in the nation at just 1.7 per 100,000. Additionally, Wyoming recorded a huge drop in the HIV rate, with prevalence of the virus falling more than 50%. See How to Test for HIV

Hepatitis B & C

Acute cases of hepatitis B virus occur at a much lower rate in Wyoming than in the U.S. as a whole. Wyoming’s most recent population-adjusted rate was just 0.3 per 100,000, compared to the most recent national rate of 1 per 100,000. Rates of acute hep C were not available for Wyoming. See How to Test for Hepatitis

HPV

In addition to being the most common STD in the world, human papillomavirus, or HPV, is also the leading cause of several types of cancer, most famously cervical cancer. In fact, HPV is so common that it’s virtually impossible to accurately estimate how many people have it right now in Wyoming. But by looking at the rate of HPV-related cancers, we can at least understand how commonly HPV goes untreated here in Wyoming. The state’s HPV cancer rate is 10.2 per 100,000, which is lower than the median rate of 11.7 per 100,000. See How to Test for HPV

STDs in Wyoming Cities & Counties

We’ve seen that most STDs are less common in Wyoming than in most other states, but not all locales in Wyoming can say the same. So how do rates vary across the state?

Chlamydia

The cities of Cheyenne and Casper accounted for about 1 in 3 chlamydia cases.

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

Fremont 522.9
Campbell 513.3
Albany 500.7
Natrona 498.6
Laramie 396.8
Goshen 393.2
Teton 383.9
Sheridan 370.4
Hot Springs 316.4
Washakie 315

Gonorrhea

The Casper and Cheyenne areas combined to account for more than 1 in 2 cases of gonorrhea in the state in 2018.

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

Natrona 119.7
Fremont 94.2
Laramie 79.4
Converse 77.7
Crook 68.1
Carbon 44.6
Goshen 44.5
Campbell 41.6
Uinta 38.5
Albany 31.6

Primary and secondary syphilis

Virtually all cases of syphilis in Wyoming were diagnosed in either Casper or Cheyenne.

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

Natrona 3.7
Sheridan 3.3
Laramie 3.1

Conclusion

Wyoming is fortunate to be among the states with the lowest prevalence of several sexually transmitted diseases and infections, including HIV, syphilis, gonorrhea and chlamydia. But as the trends here and across the country illustrate, there is no room for complacency when it comes to public health issues like STDs. That’s why it’s so important for anybody who is sexually active or was in the past to get themselves tested so that they can be sure they’ll never unwittingly contribute to the spread of sexually transmitted diseases.

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 is published by the CDC, states’ positions relative to other states will change some, though those changes are unlikely to be dramatic, since the CDC data comes from the states.