According to this more than 34% of Americans have VD.
Subtracting the many Americans who are children, elderly and other non-sexually active beings, it would seem every other adult you interact with has got themselves a hot dose floating around inside of them.
Since these are bacterial, you are clean again after taken a single dose of antibiotics. So once diagnosed, I’d think very few people actually remain having the std.
Note that the combination of antibiotics is when you have both of the stds that were mentioned. A pretty ridiculous article all together.
Why remove elderly people from the pool? If they contracted an STD in the past and it wasn’t treated (or was untreatable) then they still have it.
And let’s keep in mind, STD’s are not exclusively transmitted by sex. You can contract them by other means. So plenty of people who have never had sex may have a sexually-transmitted disease. The linked article points out, for example, that hundreds of babies are born every year with syphilis infections.