STD Rates in Pennsylvania
CDC surveillance data for Pennsylvania covering chlamydia, gonorrhea, syphilis, and HIV — with 15-year trends, state comparisons, and national benchmarks.
Pennsylvania sits in the bottom third nationally for STD burden, ranking 33rd out of 50 states with a combined rate of 575.0 per 100,000 people in 2023. But the ranking obscures something worth paying attention to: gonorrhea has risen more than 64% since 2008, and syphilis has climbed over 300% in the same window — even as both diseases showed small declines in 2023 for the first time in years.
Chlamydia is Pennsylvania's highest-volume disease by far — 54,600 cases in 2023, at a rate of 421.2 per 100,000. That puts the state about 10.6% below the national median of 471.3, which might sound like a comfortable cushion. What's less comfortable is the long-run trajectory: chlamydia rates have risen 25% since 2008 and have been effectively flat since 2020, suggesting a plateau rather than improvement. The 2023 rate is nearly identical to 2022, a difference of just 0.1 per 100,000.
Gonorrhea tells a sharper story. At 144.7 per 100,000, Pennsylvania remains just below the national median of 152.2 — but that gap has been narrowing for years. The rate was 88.1 back in 2008; it's now 64% higher. Syphilis moved in the opposite direction in 2023: after climbing relentlessly from a rate of 2.2 in 2008 to a peak of 10.8 in 2022, it dropped to 9.1 last year — a 15.7% decline. That's the first meaningful pullback in over a decade, though the rate is still more than four times what it was fifteen years ago.
HIV diagnoses in Pennsylvania have been declining gradually since 2017, when the state recorded 1,110 new cases at a rate of 10.2 per 100,000. By 2022 — the most recent year with complete data — that figure had fallen to 949 cases at a rate of 8.5. The drop in 2020 to 790 cases almost certainly reflects pandemic-related disruptions to testing, not a true reduction in transmission. If you're in Philadelphia, Pittsburgh, or Allentown, STDTest.com can help you find a testing location near you.
STD Trends in Pennsylvania
Pennsylvania's chlamydia rate has been effectively frozen since 2020 — moving from 402.0 to 421.2 over three years with almost no net change in 2023. That plateau follows a long climb: rates have risen 25% since 2008, reaching levels that still sit about 11% below the national median of 471.3. Whether the flatline reflects genuine stabilization or a testing access issue is the real question the data can't answer on its own.
Pennsylvania's gonorrhea rate has risen 64% since 2008 — from 88.1 to 144.7 per 100,000 — one of the more sustained climbs in the state's STD data. The rate is now just 4.9% below the national median of 152.2, a gap that has narrowed considerably over the past decade. A slight 0.4% dip in 2023 broke a multi-year upward streak, but it's too small to signal a reversal.
Syphilis is where Pennsylvania's long-run trend is hardest to ignore: the rate has risen more than 313% since 2008, from 2.2 to a peak of 10.8 in 2022. The 2023 drop to 9.1 — a 15.7% decline — is the first year-over-year decrease in recent history and brings the state well below the national median of 14.8. Whether that decline holds will be one of the more telling data points to watch in the next reporting cycle.
Pennsylvania's HIV diagnosis rate has trended downward since 2017, falling from 10.2 per 100,000 to 8.5 in 2022 — the most recent year for which complete data is available. The 2020 figure of 7.1 (790 cases) almost certainly reflects reduced testing access during the pandemic rather than a genuine drop in new infections; rates rebounded in 2021 and 2022. The overall direction since 2017 is encouraging, but HIV transmission remains active across the state.
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Pennsylvania vs National Average
Comparing 2023 rates against the U.S. median across all 50 states.
| Infection | Pennsylvania | US Median | Difference |
|---|---|---|---|
| Chlamydia | 421.2 | 471.3 | 10.6% below |
| Gonorrhea | 144.7 | 152.2 | 4.9% below |
| Syphilis (P&S) | 9.1 | 14.8 | 38.5% below |
What the numbers mean — and what to do about them
Pennsylvania's 575.0 combined STD rate translates to roughly 74,500 diagnoses of chlamydia, gonorrhea, and syphilis in a single year across a state of nearly 13 million people. That's not a number that jumps off the page — but it represents a steady, years-long accumulation of cases in a state that has never quite crossed back below the levels it had before the mid-2010s surge. The state ranks 33rd nationally, which means 32 states have it worse. It also means 17 have it better.
The trend that warrants the most attention isn't chlamydia — that rate has plateaued. It's the long-run arc of gonorrhea and syphilis, both of which are far more common today than they were in 2008. Gonorrhea is now 64% higher than it was fifteen years ago, and both diseases frequently show no symptoms at all. That means a significant share of those 18,758 gonorrhea cases in 2023 were in people who had no idea anything was wrong. Untreated gonorrhea can cause infertility and increases the risk of HIV transmission — which is why the case count matters even when people feel fine.
If you live in Philadelphia, Pittsburgh, or Allentown — or anywhere else in Pennsylvania — routine testing is the most practical response to what the data shows. Pennsylvania's syphilis rate dropped in 2023 for the first time in over a decade, but it's still more than four times its 2008 level. Pennsylvania's gonorrhea numbers have risen 64% since 2008 without most people noticing. STDTest.com can show you where to get tested today.
WHO SHOULD GET TESTED
Sexually active adults in Pennsylvania, particularly those in urban areas like Philadelphia, Pittsburgh, and Allentown where case concentrations tend to be highest. Given that Pennsylvania's gonorrhea rate has nearly doubled since 2008 and syphilis has quadrupled, anyone with a new or multiple partners should not wait for symptoms — both diseases are frequently asymptomatic.
HOW OFTEN
Once a year is the baseline for sexually active adults. If you have multiple partners or don't consistently use condoms, every three to six months is more appropriate — especially for gonorrhea and syphilis, which have been elevated in Pennsylvania for years and show no signs of returning to pre-2010 levels.
WHAT TO EXPECT
Most STD tests involve a urine sample, a blood draw, or a swab — often all three if you're doing a full panel. Results are typically available within a few days and are handled confidentially. Many clinics in Pennsylvania offer walk-in appointments, and some provide same-day testing with online results.
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