Counties with the highest STI rates in Washington

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March 18, 2024
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Counties with the highest STI rates in Washington

Sexually transmitted infections are on the rise, putting more people at risk as they spread. Chlamydia rates have nearly doubled since 2000, while the rate of gonorrhea went up by 50% over the same period. The Centers for Disease Control and Prevention reports that syphilis rates are reaching levels last seen in the 1950s.

But some regions of the U.S. are seeing higher rates than others.

Stacker used CDC data to look at which counties reported the highest rate of sexually transmitted infections in Washington. Counties are ranked by the rate of chlamydia infections, the most prominent STI at the national level, with gonorrhea and then syphilis rates serving as tiebreakers. This story focuses on bacterial infections, which can be cured, rather than viral infections such as HIV and herpes. At the county level, 2021 cases are the most recent available from the CDC, but state and national-level data for 2022 are also included. This story focuses on sexual transmissions and does not include congenital syphilis cases that were inherited from the mother.

Condoms are the most effective way to prevent the spread of STIs for people with multiple sexual partners, but research has found a decreasing rate of condom use among straight, bisexual, and gay male populations.

During the HIV/AIDS epidemic throughout the 1980s and 1990s, public health efforts advocating for condom use helped curb the spread of the virus. Today, however, condoms are no longer the only tool. Pills such as PrEP lower the risk of contracting HIV from sex by as much as 99%.

While more recent data is not available, the latest CDC survey from 2011-2015 showed less than half of unmarried men used condoms during the last time they had sex.

Among high school students having sex, the share using condoms has fallen from 60% in 2011 to 52% in 2021. While one-third of sexually active students used hormonal birth control, only 10% used both condoms and birth control. Methods like the pill and IUDs are effective at preventing pregnancy but do not stop the spread of STIs.

Chlamydia, gonorrhea, and syphilis are technically bacterial infections—meaning they can be cured with antibiotics—but they can still have lasting health impacts, including pelvic inflammatory disease and infertility. These risks are heightened when left untreated, which many STIs are as they don't obviously present themselves.

The CDC recommends annual testing for cisgender women, transgender men, and gender-nonconforming people with cervixes. It also recommends annual testing for males with male sexual partners. People in these groups who frequently have sex with anonymous partners should be tested every three to six months. Anyone with symptoms should always get tested according to the guidelines.

The CDC says there is little evidence that screening among straight men lowers the spread, and the agency's limited budget is put towards programs benefiting the most at-risk groups. However, some public health groups advocate for testing among all people regardless of sex and sexual orientation.

Data from the National Survey of Family Growth shows men on average have more opposite-sex sexual partners than women, and some argue that catching STIs throughout a sexual network rather than just for the most at-risk groups could curb their spread.

Soon, a pill may also help counter the spread of STIs. DoxyPEP can be taken 24 to 72 hours after unprotected sex and stops an STI before it becomes spreadable and symptomatic. The CDC has shared proposed guidelines recommending it for men who have sex with men and transgender women. The drug was originally approved for treating inhalation of anthrax, and doctors can prescribe it for off-label use.

Read on to see how STI infection rates in Washington compare nationally, and the top counties.

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Emma Rubin // Stacker

State-level statistics

- Chlamydia cases: 365.2 per 100K (#40 nationally, 28,431 cases)
- Gonorrhea cases: 146.4 per 100K (#31 nationally, 11,400 cases)
- Primary and secondary syphilis cases: 24.7 per 100K (#11 nationally, 1,920 cases)
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#39. San Juan County

- Chlamydia cases: 5.4 per 100K people (1 case)
- Gonorrhea cases: 0 cases
- Syphilis cases (non-congenital): 10.8 per 100K people (2 cases)
--- Primary and secondary syphilis: 10.8 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#38. Garfield County

- Chlamydia cases: 85.3 per 100K people (2 cases)
- Gonorrhea cases: 0 cases
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#37. Wahkiakum County

- Chlamydia cases: 87.3 per 100K people (4 cases)
- Gonorrhea cases: 21.8 per 100K people (1 case)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#36. Lincoln County

- Chlamydia cases: 115.7 per 100K people (13 cases)
- Gonorrhea cases: 8.9 per 100K people (1 case)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#35. Pacific County

- Chlamydia cases: 121.1 per 100K people (29 cases)
- Gonorrhea cases: 20.9 per 100K people (5 cases)
- Syphilis cases (non-congenital): 8.4 per 100K people (2 cases)
--- Primary and secondary syphilis: 8.4 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#34. Jefferson County

- Chlamydia cases: 122.0 per 100K people (41 case)
- Gonorrhea cases: 14.9 per 100K people (5 cases)
- Syphilis cases (non-congenital): 3.0 per 100K people (1 case)
--- Primary and secondary syphilis: 3.0 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#33. Columbia County

- Chlamydia cases: 123.7 per 100K people (5 cases)
- Gonorrhea cases: 24.7 per 100K people (1 case)
- Syphilis cases (non-congenital): 49.5 per 100K people (2 cases)
--- Primary and secondary syphilis: 24.7 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 24.7 per 100K people (1 case)
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#32. Skamania County

- Chlamydia cases: 156.1 per 100K people (19 cases)
- Gonorrhea cases: 16.4 per 100K people (2 cases)
- Syphilis cases (non-congenital): 16.4 per 100K people (2 cases)
--- Primary and secondary syphilis: 8.2 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 8.2 per 100K people (1 case)
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#31. Pend Oreille County

- Chlamydia cases: 158.4 per 100K people (22 cases)
- Gonorrhea cases: 28.8 per 100K people (4 cases)
- Syphilis cases (non-congenital): 14.4 per 100K people (2 cases)
--- Primary and secondary syphilis: 14.4 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#30. Ferry County

- Chlamydia cases: 165.0 per 100K people (12 cases)
- Gonorrhea cases: 55.0 per 100K people (4 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#29. Stevens County

- Chlamydia cases: 189.8 per 100K people (90 cases)
- Gonorrhea cases: 42.2 per 100K people (20 cases)
- Syphilis cases (non-congenital): 2.1 per 100K people (1 case)
--- Primary and secondary syphilis: 2.1 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#28. Clallam County

- Chlamydia cases: 198.2 per 100K people (155 cases)
- Gonorrhea cases: 35.8 per 100K people (28 cases)
- Syphilis cases (non-congenital): 9.0 per 100K people (7 cases)
--- Primary and secondary syphilis: 7.7 per 100K people (6 cases)
--- Nonprimary and nonsecondary early syphilis: 1.3 per 100K people (1 case)
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#27. Asotin County

- Chlamydia cases: 205.4 per 100K people (46 cases)
- Gonorrhea cases: 84.8 per 100K people (19 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#26. Island County

- Chlamydia cases: 213.9 per 100K people (187 cases)
- Gonorrhea cases: 34.3 per 100K people (30 cases)
- Syphilis cases (non-congenital): 8.0 per 100K people (7 cases)
--- Primary and secondary syphilis: 5.7 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 2.3 per 100K people (2 cases)
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#25. Klickitat County

- Chlamydia cases: 242.2 per 100K people (56 cases)
- Gonorrhea cases: 47.6 per 100K people (11 case)
- Syphilis cases (non-congenital): 8.7 per 100K people (2 cases)
--- Primary and secondary syphilis: 8.7 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#24. Okanogan County

- Chlamydia cases: 246.3 per 100K people (105 cases)
- Gonorrhea cases: 58.6 per 100K people (25 cases)
- Syphilis cases (non-congenital): 23.5 per 100K people (10 cases)
--- Primary and secondary syphilis: 11.7 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 11.7 per 100K people (5 cases)
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#23. Lewis County

- Chlamydia cases: 255.9 per 100K people (216 cases)
- Gonorrhea cases: 74.6 per 100K people (63 cases)
- Syphilis cases (non-congenital): 17.8 per 100K people (15 cases)
--- Primary and secondary syphilis: 14.2 per 100K people (12 cases)
--- Nonprimary and nonsecondary early syphilis: 3.6 per 100K people (3 cases)
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#22. Snohomish County

- Chlamydia cases: 285.5 per 100K people (2,380 cases)
- Gonorrhea cases: 95.7 per 100K people (798 cases)
- Syphilis cases (non-congenital): 20.4 per 100K people (170 cases)
--- Primary and secondary syphilis: 10.9 per 100K people (91 case)
--- Nonprimary and nonsecondary early syphilis: 9.5 per 100K people (79 cases)
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#21. Skagit County

- Chlamydia cases: 295.3 per 100K people (386 cases)
- Gonorrhea cases: 80.3 per 100K people (105 cases)
- Syphilis cases (non-congenital): 14.5 per 100K people (19 cases)
--- Primary and secondary syphilis: 12.2 per 100K people (16 cases)
--- Nonprimary and nonsecondary early syphilis: 2.3 per 100K people (3 cases)
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#20. Grays Harbor County

- Chlamydia cases: 312.3 per 100K people (240 cases)
- Gonorrhea cases: 113.2 per 100K people (87 cases)
- Syphilis cases (non-congenital): 37.7 per 100K people (29 cases)
--- Primary and secondary syphilis: 28.6 per 100K people (22 cases)
--- Nonprimary and nonsecondary early syphilis: 9.1 per 100K people (7 cases)
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#19. Thurston County

- Chlamydia cases: 321.2 per 100K people (957 cases)
- Gonorrhea cases: 102.0 per 100K people (304 cases)
- Syphilis cases (non-congenital): 19.5 per 100K people (58 cases)
--- Primary and secondary syphilis: 14.4 per 100K people (43 cases)
--- Nonprimary and nonsecondary early syphilis: 5.0 per 100K people (15 cases)
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#18. Whatcom County

- Chlamydia cases: 326.0 per 100K people (746 cases)
- Gonorrhea cases: 94.0 per 100K people (215 cases)
- Syphilis cases (non-congenital): 10.5 per 100K people (24 cases)
--- Primary and secondary syphilis: 7.9 per 100K people (18 cases)
--- Nonprimary and nonsecondary early syphilis: 2.6 per 100K people (6 cases)
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#17. Cowlitz County

- Chlamydia cases: 327.3 per 100K people (365 cases)
- Gonorrhea cases: 75.3 per 100K people (84 cases)
- Syphilis cases (non-congenital): 17.9 per 100K people (20 cases)
--- Primary and secondary syphilis: 13.5 per 100K people (15 cases)
--- Nonprimary and nonsecondary early syphilis: 4.5 per 100K people (5 cases)
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#16. King County

- Chlamydia cases: 332.4 per 100K people (7,486 cases)
- Gonorrhea cases: 191.8 per 100K people (4,319 cases)
- Syphilis cases (non-congenital): 44.8 per 100K people (1,009 cases)
--- Primary and secondary syphilis: 27.1 per 100K people (611 case)
--- Nonprimary and nonsecondary early syphilis: 17.7 per 100K people (398 cases)
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#15. Mason County

- Chlamydia cases: 335.7 per 100K people (227 cases)
- Gonorrhea cases: 115.4 per 100K people (78 cases)
- Syphilis cases (non-congenital): 23.7 per 100K people (16 cases)
--- Primary and secondary syphilis: 16.3 per 100K people (11 case)
--- Nonprimary and nonsecondary early syphilis: 7.4 per 100K people (5 cases)
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#14. Chelan County

- Chlamydia cases: 345.3 per 100K people (275 cases)
- Gonorrhea cases: 50.2 per 100K people (40 cases)
- Syphilis cases (non-congenital): 7.5 per 100K people (6 cases)
--- Primary and secondary syphilis: 6.3 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 1.3 per 100K people (1 case)
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#13. Kittitas County

- Chlamydia cases: 369.2 per 100K people (168 cases)
- Gonorrhea cases: 35.2 per 100K people (16 cases)
- Syphilis cases (non-congenital): 6.6 per 100K people (3 cases)
--- Primary and secondary syphilis: 4.4 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 2.2 per 100K people (1 case)
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#12. Clark County

- Chlamydia cases: 376.8 per 100K people (1,927 cases)
- Gonorrhea cases: 124.4 per 100K people (636 cases)
- Syphilis cases (non-congenital): 22.5 per 100K people (115 cases)
--- Primary and secondary syphilis: 15.8 per 100K people (81 case)
--- Nonprimary and nonsecondary early syphilis: 6.6 per 100K people (34 cases)
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#11. Kitsap County

- Chlamydia cases: 388.6 per 100K people (1,066 cases)
- Gonorrhea cases: 97.0 per 100K people (266 cases)
- Syphilis cases (non-congenital): 13.1 per 100K people (36 cases)
--- Primary and secondary syphilis: 10.2 per 100K people (28 cases)
--- Nonprimary and nonsecondary early syphilis: 2.9 per 100K people (8 cases)
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#10. Walla Walla County

- Chlamydia cases: 406.8 per 100K people (255 cases)
- Gonorrhea cases: 78.2 per 100K people (49 cases)
- Syphilis cases (non-congenital): 25.5 per 100K people (16 cases)
--- Primary and secondary syphilis: 22.3 per 100K people (14 cases)
--- Nonprimary and nonsecondary early syphilis: 3.2 per 100K people (2 cases)
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#9. Douglas County

- Chlamydia cases: 418.8 per 100K people (183 cases)
- Gonorrhea cases: 52.6 per 100K people (23 cases)
- Syphilis cases (non-congenital): 13.7 per 100K people (6 cases)
--- Primary and secondary syphilis: 6.9 per 100K people (3 cases)
--- Nonprimary and nonsecondary early syphilis: 6.9 per 100K people (3 cases)
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#8. Grant County

- Chlamydia cases: 441.7 per 100K people (443 cases)
- Gonorrhea cases: 123.6 per 100K people (124 cases)
- Syphilis cases (non-congenital): 17.9 per 100K people (18 cases)
--- Primary and secondary syphilis: 10.0 per 100K people (10 cases)
--- Nonprimary and nonsecondary early syphilis: 8.0 per 100K people (8 cases)
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#7. Adams County

- Chlamydia cases: 451.0 per 100K people (93 cases)
- Gonorrhea cases: 92.1 per 100K people (19 cases)
- Syphilis cases (non-congenital): 9.7 per 100K people (2 cases)
--- Primary and secondary syphilis: 9.7 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
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#6. Spokane County

- Chlamydia cases: 460.0 per 100K people (2,512 cases)
- Gonorrhea cases: 163.0 per 100K people (890 cases)
- Syphilis cases (non-congenital): 36.6 per 100K people (200 cases)
--- Primary and secondary syphilis: 20.7 per 100K people (113 cases)
--- Nonprimary and nonsecondary early syphilis: 15.9 per 100K people (87 cases)
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#5. Benton County

- Chlamydia cases: 471.8 per 100K people (991 case)
- Gonorrhea cases: 163.8 per 100K people (344 cases)
- Syphilis cases (non-congenital): 33.3 per 100K people (70 cases)
--- Primary and secondary syphilis: 17.1 per 100K people (36 cases)
--- Nonprimary and nonsecondary early syphilis: 16.2 per 100K people (34 cases)
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#4. Pierce County

- Chlamydia cases: 556.3 per 100K people (5,150 cases)
- Gonorrhea cases: 193.5 per 100K people (1,791 case)
- Syphilis cases (non-congenital): 37.4 per 100K people (346 cases)
--- Primary and secondary syphilis: 26.3 per 100K people (243 cases)
--- Nonprimary and nonsecondary early syphilis: 11.1 per 100K people (103 cases)
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#3. Franklin County

- Chlamydia cases: 667.6 per 100K people (656 cases)
- Gonorrhea cases: 193.3 per 100K people (190 cases)
- Syphilis cases (non-congenital): 29.5 per 100K people (29 cases)
--- Primary and secondary syphilis: 16.3 per 100K people (16 cases)
--- Nonprimary and nonsecondary early syphilis: 13.2 per 100K people (13 cases)
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#2. Yakima County

- Chlamydia cases: 686.6 per 100K people (1,758 cases)
- Gonorrhea cases: 233.2 per 100K people (597 cases)
- Syphilis cases (non-congenital): 48.4 per 100K people (124 cases)
--- Primary and secondary syphilis: 32.4 per 100K people (83 cases)
--- Nonprimary and nonsecondary early syphilis: 16.0 per 100K people (41 case)
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#1. Whitman County

- Chlamydia cases: 741.5 per 100K people (355 cases)
- Gonorrhea cases: 77.3 per 100K people (37 cases)
- Syphilis cases (non-congenital): 6.3 per 100K people (3 cases)
--- Primary and secondary syphilis: 6.3 per 100K people (3 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases

This story features data reporting and writing by Emma Rubin and is part of a series utilizing data automation across 49 states.

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