The 25-year-old has been suspended for doping.
Chemusto managed a couple more 1,500 meter races at almost the same level as the one in Nairobi before the season ended prematurely.
After the race in Nairobi, a doping test was taken which has turned out positive, according to the International Association of Athletics Federations' integrity unit AIU.
The Ugandan has been caught for nandrolone, the same drug that former tennis star Maria Sharapova was caught for in 2016, one of the world's most high-profile doping cases.
Suspended for four years
The suspension is backdated to July 13 and all results for the season until then will be void. The suspension period is set at four years.
In her defence, Chemusto stated that she had been prescribed medication containing nandrolone in the spring, but was unable to prove this.
The AIU also announces 18-month sentences for runners Ahmed Saber Mohamed Bakry of Egypt, Zerfe Wondemagegn of Ethiopia and Fouad Idbafdil of the refugee team for the use of banned substances.