Rifampicin susceptibility discordance between Xpert MTB/RIF G4 and Xpert Ultra before MDRT-TB treatment initiation: A case report from Uganda

Tuberculosis (TB) resistance to rifampicin, the most powerful drug leads to increase in mortality. Globally, half a million new patients develop such resistant TB each year, coupled with both inappropriate diagnosis and treatment initiation. We report a case of rifampicin resistant Mycobacterium tuberculosis whose rifampicin resistance was missed by Xpert MTB/RIF Assay G4 but detected by the Xpert MTB/RIF Ultra assay at different time points leading to increased delays for MDR-TB treatment initiation at Mulago Hospital, Kampala, Uganda. Our case report compels greater urgency in accelerating the transition to the newer assay, Ultra, to benefit from higher sensitivity of rifampicin resistance detection.