Maybe. No reason to think that track is different than cycling. Large number of people are doping. And whenever anyone runs fast, we have reason to be suspicious.
In the 2000s, people thought the East Africans were 100% clean, but thought that many of the good North Africans, Europeans, and Americans (Regina Jacobs) were dirty (look at the old Letsrun.com polls on this). Now it has become clear that many of the good East Africans are dirty. Oddly, people somehow think this means that the non-Africans are clean. I doubt it. We just learned that the East Africans are dirty, just like everyone else.
It is just human nature. People cheat.