Prevalence of several common sexually transmitted diseases (STDs) is on the increase in the commonwealth of Pennsylvania and throughout the United States. In fact, for the fourth straight year, the U.S. saw an increase in the combined rates of chlamydia, gonorrhea, and primary and secondary syphilis after the rates declining or remaining stable for many years.
Which STDs are most prevalent in Pennsylvania, where in our commonwealth are rates of certain diseases highest and how have STD rates changed here over time? To answer those questions, we’ll look at data from the federal Centers for Disease Control and Prevention and the Pennsylvania Department of Health.
Chlamydia Rates in Pennsylvania
Pennsylvania ranked ninth out of all states in sheer numbers of chlamydia infections in 2017, but after adjusting for population size, the commonwealth drops to near the bottom of the list.
Chlamydia infections per 100,000 people
Though Pennsylvania’s chlamydia rate is relatively low, the rate has risen by nearly 40% since 2003.
Pennsylvania chlamydia rate by year (cases per 100,000 people)
Pennsylvania ranks in the top half of all Northeastern states for its chlamydia infection rate.
Chlamydia infection rate, Northeastern states (cases per 100,000 people)
Gonorrhea Rates in Pennsylvania
Pennsylvania had the 10th most gonorrhea infections of any state in 2017, but the commonwealth ranks in the bottom half when considering the population-adjusted rate.
Gonorrhea infections per 100,000 people, top 25
Gonorrhea rates have risen all over the country, but Pennsylvania has seen a much more modest increase than some other places. For instance, Wyoming’s gonorrhea rate has exploded by 523% since 2013, while Pennsylvania's rate went up only about 10% in that time. However, the commonwealth’s rate is up significantly since a 21st-century low in 2009.
Pennsylvania gonorrhea rate by year (cases per 100,000 people)
Pennsylvania has the second-highest prevalence of gonorrhea among Northeastern states, though it’s far behind regional leader New York.
Gonorrhea infection rate, Northeastern states (cases per 100,000 people)
Syphilis Rates in Pennsylvania
Pennsylvania ranks close to the middle nationally when it comes to the rate of people newly diagnosed with primary or secondary syphilis, but the state comes in No. 10 in overall total cases. Still, the commonwealth’s syphilis rate is well below the national rate.
Primary and secondary syphilis infections per 100,000 people
Pennsylvania’s rate of primary and secondary syphilis has surged in recent years, climbing 68% between 2013 and 2017 alone and going up by more than 500% since 2004.
Pennsylvania primary and secondary syphilis rate by year (cases per 100,000 people)
Pennsylvania’s rate of primary and secondary syphilis is in the top half compared to regional neighbors.
Primary and secondary syphilis infection rates, Northeastern states (cases per 100,000 people)
HIV & Other STD Rates in Pennsylvania
More than 1,000 people in Pennsylvania were newly diagnosed with HIV in 2017, though both the number and population-adjusted rate fell in the commonwealth between 2016 and 2017 with each dropping by around 5%. See How to Test for HIV
Hepatitis B & C
Rates of acute hepatitis B infections in Pennsylvania are among the lowest in the country, and the commonwealth has managed to steadily bring the rate down over the years, with a 40% decrease in the rate between 2013 and 2016. The story is different for acute Hepatitis C infections, though, as Pennsylvania ranks 11th overall and has a rate about 40% higher than the national rate. Additionally, the rate of acute hep C cases has surged by 260% since 2012. See How to Test for Hepatitis
Human papillomavirus is by far the most common STD in the world. It’s so common, in fact, that estimating in any given year how many people have contracted it is virtually impossible. But because HPV is the leading cause of several types of cancer, including cervical, penile and anal cancer, examining the rate of HPV-caused cancer cases in each state can help illustrate how prevalent untreated high-risk HPV is. In Pennsylvania, HPV-related cancer is diagnosed at a rate of 12.4 per 100,000 people, putting the commonwealth just over the national median of 11.7 per 100,000. See How to Test for HPV
STDs in Pennsylvania Cities & Counties
Looking at the commonwealth overall reveals just one portion of the full picture of sexual health in Pennsylvania. That’s because Pennsylvania is home to multiple metro areas that often carry more weight in health statistics. For instance, the Philadelphia metro area (which includes portions of Delaware and New Jersey) has the 10th highest chlamydia rate of any metro area in the country.
About a third of all chlamydia cases in Pennsylvania in 2017 were in people living in Philadelphia.
Pennsylvania counties by chlamydia infection rate (cases per 100,000 people)
Philadelphia accounted for about 48% of all gonorrhea cases in Pennsylvania in 2017, and the Pittsburgh area added another 12%.
Pennsylvania counties by gonorrhea infection rate (cases per 100,000 people)
Primary and secondary syphilis
More than half of the primary and secondary syphilis cases in Pennsylvania in 2017 were diagnosed in Philadelphia.
Pennsylvania counties by primary and secondary syphilis infection rate (cases per 100,000 people)
While most STDs have seen their prevalence rise over the past few years in the commonwealth of Pennsylvania, the reality is that most people here who have STDs probably don’t know about it. That’s because most STDs either don’t display symptoms or they have symptoms that are easily mistaken for other issues. The only way to know for sure that you are healthy and won’t pass along a potentially serious infection to your sexual partners is to get yourself tested for the STDs for which you’re most at risk.
- Centers for Disease Control and Prevention, Sexually Transmitted Disease Surveillance 2017. (2018). Retrieved from https://www.cdc.gov/std/stats17/SRtables.pdf
- Pennsylvania Department of Health, Enterprise Data Dissemination Informatics Exchange (EDDIE), interactive data table builder. (2019). Retrieved from https://www.health.pa.gov/topics/HealthStatistics/EDDIE/Pages/EDDIE.aspx
- Centers for Disease Control and Prevention, HPV-Associated Cancer Rates by State, 2011-2015. (2018). Retrieved from https://www.cdc.gov/cancer/hpv/statistics/state/index.htm
- Centers for Disease Control and Prevention, HIV Surveillance Report, Diagnoses of HIV Infection in the United States and Dependent Areas, 2017. (2018). Retrieved from https://www.cdc.gov/hiv/pdf/library/reports/surveillance/cdc-hiv-surveillance-report-2017-vol-29.pdf
- Centers for Disease Control and Prevention, Surveillance for Viral Hepatitis – United States, 2016. (2018). Retrieved from https://www.cdc.gov/hepatitis/statistics/2016surveillance/index.htm
Note: The CDC publishes comprehensive STD data on only three of the many conditions that are sexually transmitted — chlamydia, gonorrhea, and primary and secondary syphilis. Many other STDs are not classified as nationally notifiable diseases, meaning states are not legally obligated to report infection rates. Also, while the CDC collects data for the District of Columbia, the population density of the district prevents it from being included in rankings.