Kenya cannot assure the world that any of its athletes is unequivocally drug-free, at least according to tests by its national antidoping program. World Anti-Doping Agency officials say the Kenyan antidoping agency exists in name only.
http://www.nytimes.com/2015/11/05/sports/kenya-excels-in-running-but-lags-in-antidoping.html?_r=0
http://www.nytimes.com/2015/11/05/sports/kenya-excels-in-running-but-lags-in-antidoping.html?_r=0