bacteriuria is the presence of bacteria in a urine sample, identified microscopically, by dipstick nitrite/leukocyte esterase screening, or definitively by quantitative urine culture. It is distinguished from a true UTI, which requires bacteriuria plus clinical signs or symptoms (dysuria, frequency, urgency, suprapubic or flank pain, fever); bacteriuria without symptoms is termed asymptomatic bacteriuria (ASB) and, outside of pregnancy or pre-urologic-procedure contexts, generally does not warrant treatment. Significant bacteriuria is typically defined as ≥10⁵ CFU/mL of a single uropathogen on clean-catch specimen (or lower thresholds for catheterized/suprapubic specimens), distinguishing true infection or colonization from contamination. Contamination from poor collection technique (mixed flora, epithelial cells) is a key confounder in interpretation. Bacteriuria is especially common in the presence of an indwelling catheter (catheter-associated bacteriuria), in elderly patients, and in pregnancy, where untreated ASB carries a meaningfully increased risk of progression to pyelonephritis and adverse pregnancy outcomes, making it one of the few settings where ASB is actively screened for and treated.
Noun-forming suffix — “condition of urine” or “condition involving urine”
The term is a 20th-century medical coinage combining the New Latin genus name Bacterium (itself formalized in the early 1800s by Christian Gottfried Ehrenberg from the Greek root) with the productive suffix -uria, which forms the entire family of urine-finding terms: hematuria (blood in urine), pyuria (pus/WBCs in urine), glycosuria (glucose in urine), and proteinuria (protein in urine). Unlike many Greek/Latin-rooted pathology terms describing a disease process, -uria terms simply describe an abnormal finding in urine, which is why bacteriuria itself is not synonymous with infection.
ALIASES / ALTERNATE TERMS
Asymptomatic bacteriuria (ASB) — bacteriuria meeting quantitative culture criteria without accompanying urinary symptoms; the clinically important subtype for coding/treatment decisions.
Significant bacteriuria — quantitative threshold (≥10⁵ CFU/mL clean-catch) used to distinguish true bacteriuria from specimen contamination.
Covert bacteriuria — older/lay synonym for asymptomatic bacteriuria, still occasionally seen in obstetric literature.
Catheter-associated bacteriuria (CAB) — bacteriuria occurring in the setting of an indwelling urinary catheter; becomes CAUTI only if symptomatic.
pyuria — presence of white blood cells (pus) in urine; often coexists with bacteriuria but reflects host inflammatory response rather than the organism itself.
funguria — the fungal (usually Candida) analog of bacteriuria; coded and managed differently.
cystitis — symptomatic bladder infection; a common clinical correlate of significant bacteriuria.
pyelonephritis — ascending kidney infection; the major feared complication of untreated bacteriuria in pregnancy.
urosepsis — systemic sepsis originating from a urinary source; represents bacteriuria that has progressed to a life-threatening systemic response.
Contamination — false bacteriuria from poor collection technique; distinguished from true bacteriuria by quantitative colony counts and specimen quality (squamous epithelial cells).
Susceptibility studies, antimicrobial agent; microdilution or agar dilution, each multi-antimicrobial, per plate
⚠️ Coding Note: The single most important distinction for bacteriuria coding is symptomatic vs. asymptomatic: R82.71 is an abnormal-finding code and should never be assigned when the documentation supports a clinical UTI diagnosis (N39.0 or site-specific code) — R82.71 is reserved for incidental, asymptomatic lab findings only. In pregnancy, trimester specificity is mandatory for the O23 series, and unlike the non-obstetric setting, ASB in pregnancy is actively treated and should generally be coded as an infection (O23.1-/O23.4-) rather than as an incidental finding, since it is managed as a true condition of pregnancy. On inpatient profee claims, watch for documentation of “positive urine culture” or “bacteria in urine” without a stated symptom set — this should trigger a physician query to clarify UTI vs. asymptomatic bacteriuria vs. contamination/colonization, since misclassifying incidental bacteriuria as a UTI is a common audit target (CAUTI surveillance in particular). If the catheter is implicated, confirm whether T83.51XA (CAUTI) applies versus simple catheter-associated asymptomatic bacteriuria, which is not separately coded as an infection.