The definition of candiduria is enigmatic. Although most
studies rely on culture, both microscopic visualization in urine
and culture of urine could be employed. Of concern is that
neither the diagnostic criterion (CFU cutoff) nor the collection
technique (suprapubic aspiration versus bag collection) for
neonatal urinary candidiasis is standardized. Even in adults,
CFU criteria to diagnose candiduria range from 103
to 105
CFU/ml urine. In some studies candiduria is even differentially
defined for women and men (57). Treatment trials funded by
the National Institutes of Health generally use the lower CFU
cutoff (10
3
) as their definition (241). In addition, in most retrospective studies standard urine cultures were screened for
candiduria, which means that urine was cultured on MacConkey and blood agar only. Some laboratories culture urines
on Uriselect agar, which is a chromogenic agar that allows
the preliminary identification of predominantly bacterial uropathogens (195). Although these culture methods are certainly
sufficient to identify bacteria, they may be significantly less
sensitive to recover C. albicansand non-C. albicansspecies.
Consistent with this concern, prospective studies in which
urine was cultured on Sabouraud dextrose (SD) agar, a standard fungal medium, have reported higher numbers of non-C.
albicansspecies (129, 186). It is noteworthy that the fungal
burden could be relevant, because a statistically significant
correlation between heavy candiduria (10
4
CFU/ml urine)
and a high PittetCandidacolonization index (0.5) has been
established (46). In summary, variable cutoff definitions and
unreliable culture techniques may skew analysis of the incidence and outcome of candiduria. These discrepancies have
not been adequately addressed in most studies.