Can you find the mid-2015 report mentioned in that article? The link is dead.

Note that it was first referenced here: https://www.atlanticcouncil.org/blogs/ukrainealert/ukraine-should-do-more-to-combat-human-trafficking/

Note also that most of those problems developed before 2014, when Russias politicians controlled UKraine. It was among the many reasons Ukrainians protested against the Russian mafia in Ukraine, resulting in the expulsion of many of them. Since then, Ukraine politicians have been in the process of getting the the corrupt Russian influence out of Ukraine.