Counties with the highest STI rates in Illinois

Emma Rubin // Stacker
- Chlamydia cases: 568.8 per 100K (#9 nationally, 71,564 cases)
- Gonorrhea cases: 210.2 per 100K (#16 nationally, 26,442 cases)
- Primary and secondary syphilis cases: 11.6 per 100K (#35 nationally, 1,457 cases)
State-level statistics
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- Chlamydia cases: 271.8 per 100K people (46 cases)
- Gonorrhea cases: 35.5 per 100K people (6 cases)
- Syphilis cases (non-congenital): 11.8 per 100K people (2 cases)
--- Primary and secondary syphilis: 5.9 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 5.9 per 100K people (1 case)
#50. Union County
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- Chlamydia cases: 277.7 per 100K people (78 cases)
- Gonorrhea cases: 138.9 per 100K people (39 cases)
- Syphilis cases (non-congenital): 3.6 per 100K people (1 case)
--- Primary and secondary syphilis: 3.6 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#49. Montgomery County
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- Chlamydia cases: 280.3 per 100K people (155 cases)
- Gonorrhea cases: 77.8 per 100K people (43 cases)
- Syphilis cases (non-congenital): 1.8 per 100K people (1 case)
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 1.8 per 100K people (1 case)
#48. Whiteside County
Leigh Trail // Shutterstock
- Chlamydia cases: 280.3 per 100K people (43 cases)
- Gonorrhea cases: 78.2 per 100K people (12 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#47. De Witt County
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- Chlamydia cases: 281.0 per 100K people (43 cases)
- Gonorrhea cases: 130.7 per 100K people (20 cases)
- Syphilis cases (non-congenital): 6.5 per 100K people (1 case)
--- Primary and secondary syphilis: 6.5 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#46. Clark County
Altosvic // Shutterstock
- Chlamydia cases: 283.9 per 100K people (56 cases)
- Gonorrhea cases: 60.8 per 100K people (12 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#45. Douglas County
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- Chlamydia cases: 287.4 per 100K people (50 cases)
- Gonorrhea cases: 97.7 per 100K people (17 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#44. Hancock County
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- Chlamydia cases: 288.2 per 100K people (46 cases)
- Gonorrhea cases: 181.7 per 100K people (29 cases)
- Syphilis cases (non-congenital): 6.3 per 100K people (1 case)
--- Primary and secondary syphilis: 6.3 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#43. Wayne County
Henryk Sadura // Shutterstock
- Chlamydia cases: 295.5 per 100K people (35 cases)
- Gonorrhea cases: 118.2 per 100K people (14 cases)
- Syphilis cases (non-congenital): 16.9 per 100K people (2 cases)
--- Primary and secondary syphilis: 16.9 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#42. Greene County
Kenneth Keifer // Shutterstock
- Chlamydia cases: 299.7 per 100K people (31 case)
- Gonorrhea cases: 67.7 per 100K people (7 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#41. Cumberland County
PICTOR PICTURES // Shutterstock
- Chlamydia cases: 301.0 per 100K people (19 cases)
- Gonorrhea cases: 95.1 per 100K people (6 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#40. Henderson County
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- Chlamydia cases: 302.2 per 100K people (16 cases)
- Gonorrhea cases: 37.8 per 100K people (2 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#39. Stark County
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- Chlamydia cases: 302.5 per 100K people (408 cases)
- Gonorrhea cases: 77.1 per 100K people (104 cases)
- Syphilis cases (non-congenital): 8.2 per 100K people (11 case)
--- Primary and secondary syphilis: 2.2 per 100K people (3 cases)
--- Nonprimary and nonsecondary early syphilis: 5.9 per 100K people (8 cases)
#38. Kendall County
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- Chlamydia cases: 312.8 per 100K people (153 cases)
- Gonorrhea cases: 94.1 per 100K people (46 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#37. Henry County
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- Chlamydia cases: 322.9 per 100K people (51 case)
- Gonorrhea cases: 196.3 per 100K people (31 case)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#36. Richland County
JL Jahn // Shutterstock
- Chlamydia cases: 325.4 per 100K people (173 cases)
- Gonorrhea cases: 37.6 per 100K people (20 cases)
- Syphilis cases (non-congenital): 13.2 per 100K people (7 cases)
--- Primary and secondary syphilis: 11.3 per 100K people (6 cases)
--- Nonprimary and nonsecondary early syphilis: 1.9 per 100K people (1 case)
#35. Boone County
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- Chlamydia cases: 357.1 per 100K people (59 cases)
- Gonorrhea cases: 296.6 per 100K people (49 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#34. Edgar County
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- Chlamydia cases: 358.4 per 100K people (52 cases)
- Gonorrhea cases: 48.2 per 100K people (7 cases)
- Syphilis cases (non-congenital): 6.9 per 100K people (1 case)
--- Primary and secondary syphilis: 6.9 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#33. Moultrie County
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- Chlamydia cases: 379.6 per 100K people (140 cases)
- Gonorrhea cases: 162.7 per 100K people (60 cases)
- Syphilis cases (non-congenital): 5.4 per 100K people (2 cases)
--- Primary and secondary syphilis: 2.7 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 2.7 per 100K people (1 case)
#32. Jefferson County
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- Chlamydia cases: 381.9 per 100K people (2,663 cases)
- Gonorrhea cases: 108.9 per 100K people (759 cases)
- Syphilis cases (non-congenital): 9.5 per 100K people (66 cases)
--- Primary and secondary syphilis: 5.7 per 100K people (40 cases)
--- Nonprimary and nonsecondary early syphilis: 3.7 per 100K people (26 cases)
#31. Will County
marythebarberphotos // Shutterstock
- Chlamydia cases: 384.6 per 100K people (144 cases)
- Gonorrhea cases: 213.7 per 100K people (80 cases)
- Syphilis cases (non-congenital): 8.0 per 100K people (3 cases)
--- Primary and secondary syphilis: 5.3 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 2.7 per 100K people (1 case)
#30. Franklin County
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- Chlamydia cases: 387.9 per 100K people (2,000 cases)
- Gonorrhea cases: 89.2 per 100K people (460 cases)
- Syphilis cases (non-congenital): 10.5 per 100K people (54 cases)
--- Primary and secondary syphilis: 6.4 per 100K people (33 cases)
--- Nonprimary and nonsecondary early syphilis: 4.1 per 100K people (21 case)
#29. Kane County
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- Chlamydia cases: 398.5 per 100K people (149 cases)
- Gonorrhea cases: 224.7 per 100K people (84 cases)
- Syphilis cases (non-congenital): 8.0 per 100K people (3 cases)
--- Primary and secondary syphilis: 5.3 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 2.7 per 100K people (1 case)
#28. Marion County
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- Chlamydia cases: 414.2 per 100K people (277 cases)
- Gonorrhea cases: 276.6 per 100K people (185 cases)
- Syphilis cases (non-congenital): 13.5 per 100K people (9 cases)
--- Primary and secondary syphilis: 6.0 per 100K people (4 cases)
--- Nonprimary and nonsecondary early syphilis: 7.5 per 100K people (5 cases)
#27. Williamson County
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- Chlamydia cases: 448.0 per 100K people (291 case)
- Gonorrhea cases: 167.8 per 100K people (109 cases)
- Syphilis cases (non-congenital): 4.6 per 100K people (3 cases)
--- Primary and secondary syphilis: 4.6 per 100K people (3 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#26. Adams County
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- Chlamydia cases: 448.8 per 100K people (3,192 cases)
- Gonorrhea cases: 92.4 per 100K people (657 cases)
- Syphilis cases (non-congenital): 2.4 per 100K people (17 cases)
--- Primary and secondary syphilis: .7 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 1.7 per 100K people (12 cases)
#25. Lake County
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- Chlamydia cases: 449.2 per 100K people (1,188 cases)
- Gonorrhea cases: 217.8 per 100K people (576 cases)
- Syphilis cases (non-congenital): 7.9 per 100K people (21 case)
--- Primary and secondary syphilis: 6.4 per 100K people (17 cases)
--- Nonprimary and nonsecondary early syphilis: 1.5 per 100K people (4 cases)
#24. Madison County
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- Chlamydia cases: 450.3 per 100K people (105 cases)
- Gonorrhea cases: 244.4 per 100K people (57 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#23. Saline County
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- Chlamydia cases: 468.9 per 100K people (231 case)
- Gonorrhea cases: 188.8 per 100K people (93 cases)
- Syphilis cases (non-congenital): 12.2 per 100K people (6 cases)
--- Primary and secondary syphilis: 10.1 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 2.0 per 100K people (1 case)
#22. Knox County
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- Chlamydia cases: 503.7 per 100K people (141 case)
- Gonorrhea cases: 300.1 per 100K people (84 cases)
- Syphilis cases (non-congenital): 7.1 per 100K people (2 cases)
--- Primary and secondary syphilis: 7.1 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#21. Logan County
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- Chlamydia cases: 529.3 per 100K people (233 cases)
- Gonorrhea cases: 168.1 per 100K people (74 cases)
- Syphilis cases (non-congenital): 6.8 per 100K people (3 cases)
--- Primary and secondary syphilis: 4.5 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 2.3 per 100K people (1 case)
#20. Stephenson County
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- Chlamydia cases: 535.8 per 100K people (538 cases)
- Gonorrhea cases: 167.3 per 100K people (168 cases)
- Syphilis cases (non-congenital): 8.0 per 100K people (8 cases)
--- Primary and secondary syphilis: 5.0 per 100K people (5 cases)
--- Nonprimary and nonsecondary early syphilis: 3.0 per 100K people (3 cases)
#19. Dekalb County
Kent Raney // Shutterstock
- Chlamydia cases: 545.8 per 100K people (780 cases)
- Gonorrhea cases: 263.1 per 100K people (376 cases)
- Syphilis cases (non-congenital): 11.9 per 100K people (17 cases)
--- Primary and secondary syphilis: 7.7 per 100K people (11 case)
--- Nonprimary and nonsecondary early syphilis: 4.2 per 100K people (6 cases)
#18. Rock Island County
Samantha J. Darr // Shutterstock
- Chlamydia cases: 561.2 per 100K people (183 cases)
- Gonorrhea cases: 282.2 per 100K people (92 cases)
- Syphilis cases (non-congenital): 6.1 per 100K people (2 cases)
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 6.1 per 100K people (2 cases)
#17. Morgan County
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- Chlamydia cases: 563.7 per 100K people (72 cases)
- Gonorrhea cases: 195.7 per 100K people (25 cases)
- Syphilis cases (non-congenital): 15.7 per 100K people (2 cases)
--- Primary and secondary syphilis: 7.8 per 100K people (1 case)
--- Nonprimary and nonsecondary early syphilis: 7.8 per 100K people (1 case)
#16. Cass County
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- Chlamydia cases: 572.3 per 100K people (978 cases)
- Gonorrhea cases: 192.5 per 100K people (329 cases)
- Syphilis cases (non-congenital): 7.6 per 100K people (13 cases)
--- Primary and secondary syphilis: 4.1 per 100K people (7 cases)
--- Nonprimary and nonsecondary early syphilis: 3.5 per 100K people (6 cases)
#15. Mclean County
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- Chlamydia cases: 595.7 per 100K people (635 cases)
- Gonorrhea cases: 307.7 per 100K people (328 cases)
- Syphilis cases (non-congenital): 2.8 per 100K people (3 cases)
--- Primary and secondary syphilis: 1.9 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: .9 per 100K people (1 case)
#14. Kankakee County
Hank Shiffman // Shutterstock
- Chlamydia cases: 612.0 per 100K people (31 case)
- Gonorrhea cases: 355.4 per 100K people (18 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#13. Pulaski County
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- Chlamydia cases: 675.3 per 100K people (1,315 cases)
- Gonorrhea cases: 422.6 per 100K people (823 cases)
- Syphilis cases (non-congenital): 22.1 per 100K people (43 cases)
--- Primary and secondary syphilis: 16.4 per 100K people (32 cases)
--- Nonprimary and nonsecondary early syphilis: 5.6 per 100K people (11 case)
#12. Sangamon County
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- Chlamydia cases: 716.7 per 100K people (2,029 cases)
- Gonorrhea cases: 325.7 per 100K people (922 cases)
- Syphilis cases (non-congenital): 29.3 per 100K people (83 cases)
--- Primary and secondary syphilis: 15.2 per 100K people (43 cases)
--- Nonprimary and nonsecondary early syphilis: 14.1 per 100K people (40 cases)
#11. Winnebago County
Roberto Galan // Shutterstock
- Chlamydia cases: 729.2 per 100K people (341 case)
- Gonorrhea cases: 256.6 per 100K people (120 cases)
- Syphilis cases (non-congenital): 2.1 per 100K people (1 case)
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 2.1 per 100K people (1 case)
#10. Coles County
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- Chlamydia cases: 764.1 per 100K people (205 cases)
- Gonorrhea cases: 234.8 per 100K people (63 cases)
- Syphilis cases (non-congenital): 7.5 per 100K people (2 cases)
--- Primary and secondary syphilis: 7.5 per 100K people (2 cases)
--- Nonprimary and nonsecondary early syphilis: 0 cases
#9. Mcdonough County
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- Chlamydia cases: 764.3 per 100K people (39,536 cases)
- Gonorrhea cases: 343.0 per 100K people (17,744 cases)
- Syphilis cases (non-congenital): 37.2 per 100K people (1,922 cases)
--- Primary and secondary syphilis: 19.8 per 100K people (1,024 cases)
--- Nonprimary and nonsecondary early syphilis: 17.4 per 100K people (898 cases)
#8. Cook County
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- Chlamydia cases: 774.7 per 100K people (1,974 cases)
- Gonorrhea cases: 402.7 per 100K people (1,026 cases)
- Syphilis cases (non-congenital): 33.4 per 100K people (85 cases)
--- Primary and secondary syphilis: 22.8 per 100K people (58 cases)
--- Nonprimary and nonsecondary early syphilis: 10.6 per 100K people (27 cases)
#7. St. Clair County
Roberto Galan // Shutterstock
- Chlamydia cases: 775.3 per 100K people (39 cases)
- Gonorrhea cases: 457.3 per 100K people (23 cases)
- Syphilis cases (non-congenital): 0 cases
--- Primary and secondary syphilis: 0 cases
--- Nonprimary and nonsecondary early syphilis: 0 cases
#6. Alexander County
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- Chlamydia cases: 784.7 per 100K people (1,616 cases)
- Gonorrhea cases: 350.1 per 100K people (721 case)
- Syphilis cases (non-congenital): 14.6 per 100K people (30 cases)
--- Primary and secondary syphilis: 7.3 per 100K people (15 cases)
--- Nonprimary and nonsecondary early syphilis: 7.3 per 100K people (15 cases)
#5. Champaign County
Roberto Galan // Shutterstock
- Chlamydia cases: 786.6 per 100K people (575 cases)
- Gonorrhea cases: 469.3 per 100K people (343 cases)
- Syphilis cases (non-congenital): 20.5 per 100K people (15 cases)
--- Primary and secondary syphilis: 16.4 per 100K people (12 cases)
--- Nonprimary and nonsecondary early syphilis: 4.1 per 100K people (3 cases)
#4. Vermilion County
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- Chlamydia cases: 849.3 per 100K people (1,524 cases)
- Gonorrhea cases: 585.7 per 100K people (1,051 case)
- Syphilis cases (non-congenital): 21.7 per 100K people (39 cases)
--- Primary and secondary syphilis: 16.7 per 100K people (30 cases)
--- Nonprimary and nonsecondary early syphilis: 5.0 per 100K people (9 cases)
#3. Peoria County
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- Chlamydia cases: 857.2 per 100K people (878 cases)
- Gonorrhea cases: 577.0 per 100K people (591 case)
- Syphilis cases (non-congenital): 10.7 per 100K people (11 case)
--- Primary and secondary syphilis: 9.8 per 100K people (10 cases)
--- Nonprimary and nonsecondary early syphilis: 1.0 per 100K people (1 case)
#2. Macon County
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- Chlamydia cases: 981.6 per 100K people (516 cases)
- Gonorrhea cases: 635.4 per 100K people (334 cases)
- Syphilis cases (non-congenital): 45.7 per 100K people (24 cases)
--- Primary and secondary syphilis: 28.5 per 100K people (15 cases)
--- Nonprimary and nonsecondary early syphilis: 17.1 per 100K people (9 cases)

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

#1. Jackson County
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