First evidence of human infection by the kinetoplastid flagellate Dimastigella trypaniformis in a patient with urinary tract infection.

We present a case of an 88-year-old man with symptoms consistent with a urinary tract infection, whose diagnostic workup uncovered a previously unrecognized motile flagellated protozoan. Molecular identification confirmed the organism as Dimastigella trypaniformis, a free-living kinetoplastid from the Rhynchomonadidae family. Known only from soil samples in Scotland and termite gut contents in Australia and Germany, Dimastigella trypaniformis has not been previously reported to infect vertebrate hosts. To our knowledge, this case represents the first potential documented instance of D. trypaniformis reported from human urine, broadening the spectrum of urinary pathogens to include this rare organism. This report highlights the need to consider emerging parasitic agents in cases of hematuria and complex urinary tract infections, underscoring the value of molecular diagnostics in identifying atypical and emergent pathogens.