9. Delaware
Chlamydia Rate: 567.2 per 100,000 people
Gonorrhea Rate: 179.9 per 100, 000 people
Syphilis Rate: 6.1 per 100, 000 people
On the 9th place of the states with the highest STD rates in the US in 2018 is Delaware. Even though the syphilis rate is not among the highest ones, its chlamydia rate is very high on the scale.

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