STD Rates in Delaware
CDC surveillance data for Delaware covering chlamydia, gonorrhea, syphilis, and HIV — with 15-year trends, state rankings, and national comparisons.
Delaware is a small state — just over a million people — but its STD burden puts it well inside the top third nationally. In 2023, the combined rate of 722 cases per 100,000 residents ranked 16th out of 50 states. That alone would be notable, but what makes Delaware's picture more complicated is that two of its three core STDs are trending upward simultaneously, after years of moving in different directions.
Chlamydia is the volume story. With 5,703 cases diagnosed in 2023 at a rate of 552.7 per 100,000, Delaware sits 17% above the national median of 471.3. That gap isn't new — chlamydia has run above the national middle for most of the past 15 years — but the direction has shifted. After dipping in 2020 and 2021, rates have climbed in back-to-back years, rising 8.7% from 2022 to 2023 alone. The long-run rise since 2008 is 25%, and there's little in the recent trend to suggest it's leveling off.
Gonorrhea tells a shorter story with a sharper edge. At 151.9 per 100,000, Delaware sits just below the national median of 152.2 — a near-exact match, which would seem unremarkable if it weren't for what surrounds that number. The rate has risen 27% since 2008 and ticked up again in 2023 after a brief retreat in 2022. Syphilis, meanwhile, pulled in the opposite direction: after spiking to 23.4 per 100,000 in 2022 — the highest rate in Delaware's recent history — it fell 25.6% in 2023 to 17.4. That's still above the national median of 14.8, and still more than fifteen times the rate recorded in 2008, when syphilis was barely registering in the state at all.
HIV diagnoses in Delaware ran between 84 and 126 new cases per year from 2017 to 2022, the most recent period with complete data. The rate fell steadily through 2021, reaching 9.8 per 100,000, before climbing back to 14.5 in 2022 — nearly matching 2017 levels. The dip in 2020 and 2021 almost certainly reflects disrupted testing access during the pandemic, not a genuine reduction in transmission. If you're in Wilmington, Dover, or Newark, STDTest.com can help you find a local testing site quickly.
STD Trends in Delaware
Delaware's chlamydia rate has never really stabilized — it's been running above the national median for years, and the recent trend is pointing the wrong way. After two years of lower rates during the pandemic period, cases climbed back through 2022 and accelerated further in 2023, reaching 552.7 per 100,000 — 17% above the US median. The long-run rise of 25% since 2008 isn't steep by national standards, but the back-to-back annual increases suggest the brief post-pandemic lull is over.
Delaware's gonorrhea rate has tracked the national median closely for years, and in 2023 it landed almost exactly on it — 151.9 per 100,000 against a national median of 152.2. That proximity obscures a longer trend: the rate is up 27% since 2008, and after dropping in 2022, it rose again in 2023. The state hasn't consistently broken above the national middle, but it hasn't pulled away from it either.
The most striking movement in Delaware's recent STD data is syphilis — and it cuts both ways. After climbing from near-zero in the early 2000s to a peak of 23.4 per 100,000 in 2022, the rate dropped 25.6% in 2023 to 17.4. That's a real decline, but it still leaves Delaware above the national median of 14.8, and the long-run picture remains extreme: syphilis rates are more than fifteen times higher today than they were in 2008.
Delaware's HIV data runs through 2022, and the trend over that six-year window is uneven. New diagnoses fell from 123 cases in 2017 to 84 in 2021 — a rate of 9.8 per 100,000 — before jumping to 126 cases in 2022, pushing the rate back to 14.5. The apparent improvement in 2020 and 2021 is likely a reflection of reduced testing access during the pandemic rather than a genuine drop in transmission, which makes the 2022 rebound harder to interpret in isolation.
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Delaware vs National Average
Comparing 2023 rates against the U.S. median across all 50 states.
| Infection | Delaware | US Median | Difference |
|---|---|---|---|
| Chlamydia | 552.7 | 471.3 | 17.3% above |
| Gonorrhea | 151.9 | 152.2 | 0.2% below |
| Syphilis (P&S) | 17.4 | 14.8 | 17.6% above |
What the numbers mean — and what to do about them
In 2023, Delaware recorded 7,450 combined diagnoses of chlamydia, gonorrhea, and syphilis across a population of just over one million people — a rate of 722 per 100,000. That places the state 16th in the country, well above the national middle. Put another way, roughly one in every 138 Delaware residents received a new diagnosis for one of these three infections last year. Those are diagnosed cases. The actual number of infections is higher, because most people with chlamydia or gonorrhea never develop symptoms and never get tested.
Chlamydia is the disease most responsible for Delaware's elevated ranking, and its trajectory is moving in the wrong direction. After a pandemic-era dip, the rate has risen two years in a row and now sits 17% above the national median. Chlamydia is asymptomatic in the majority of cases — estimates suggest up to 70% of infected women and a significant share of men have no symptoms at all. That means transmission continues quietly, and untreated infections can lead to pelvic inflammatory disease, infertility, and increased vulnerability to other STDs including HIV. Syphilis, meanwhile, has pulled back from its 2022 peak but remains above the national median — a reminder that even a declining trend doesn't mean the pressure has lifted.
If you live in Wilmington, Dover, or Newark, Delaware's STD numbers are relevant to you — not as a statistic, but as context for a practical decision. The state's chlamydia rate has been climbing, its gonorrhea rate is essentially at the national median and rising, and syphilis — while down from its 2022 high — is still above average. Annual testing is the minimum for most sexually active adults; more frequent testing makes sense depending on your situation. Delaware's syphilis rate rose more than 15-fold in 15 years without most people noticing. STDTest.com can show you where to get tested in Delaware today.
WHO SHOULD GET TESTED
Sexually active Delaware residents of any age — but especially those under 25, where chlamydia rates are highest nationally, and those with multiple partners in Wilmington or other urban areas where the combined STD burden is concentrated. Delaware's gonorrhea rate sits right at the national median, and its syphilis rate remains above it, so no population here is at uniformly low risk.
HOW OFTEN
Once a year is a reasonable floor if you're sexually active. Given Delaware's chlamydia rate has risen two years running and its syphilis rate spiked sharply before retreating, every 3 to 6 months is more appropriate if you have multiple partners or aren't consistently using condoms. Don't rely on symptoms — most of these infections don't produce any.
WHAT TO EXPECT
STD testing is fast and straightforward. Depending on the site, it typically involves a urine sample, a swab, or a blood draw — sometimes a combination. Most results come back within a few days. Many testing locations in Delaware offer confidential or anonymous options, and treatment for chlamydia, gonorrhea, and syphilis is available and effective when caught early.
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