Prognostic value of semi-quantitative bacteruria counts in the diagnosis of group B streptococcus urinary tract infection: a 4-year retrospective study in adult patients

<p>Abstract</p> <p>Background</p> <p>Semi-quantitative bacteruria counts (s-QBC) are important in the diagnosis of urinary tract infection (UTI) due to most uropathogens. The prognostic value of s-QBC for diagnosis of UTI due to group B streptococcus (GBS) is unknown. I...

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Bibliographic Details
Main Authors: Tan Chee K, Ulett Kimberly B, Steele Michael, Benjamin William H, Ulett Glen C
Format: Article
Language:English
Published: BMC 2012-10-01
Series:BMC Infectious Diseases
Subjects:
Online Access:http://www.biomedcentral.com/1471-2334/12/273
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Summary:<p>Abstract</p> <p>Background</p> <p>Semi-quantitative bacteruria counts (s-QBC) are important in the diagnosis of urinary tract infection (UTI) due to most uropathogens. The prognostic value of s-QBC for diagnosis of UTI due to group B streptococcus (GBS) is unknown. In this study, we assessed the value of s-QBC for differentiating acute GBS UTI from asymptomatic bacteruria (ABU), independent of other potential prognostic indicators.</p> <p>Methods</p> <p>Medical record review and urinalysis (UA) values for 1593 patients who had urinary GBS isolated (10<sup>3</sup> to ≥10<sup>5</sup> CFU/ml) during a four-year period were analyzed using binary logistic regression to determine the predictive values of s-QBC, age, and gender for infection category (acute UTI, ABU) based on the clinical diagnosis.</p> <p>Results</p> <p>s-QBC alone had a strong predictive value for infection category but only for ABU. Multivariate logistic regression showed similar predictive power of s-QBC for infection category using age as a co-predictor, which was also independently associated with infection category. Typical s-QBC cut-off values that are commonly used in diagnostic settings had no significant power in predicting infection category. Among other UA measures, proteinuria and hematuria were significantly associated with acute infection.</p> <p>Conclusions</p> <p>Together, these data show that s-QBC is not useful in the differential diagnosis of GBS UTI. Among the patients in this study, age was an equally effective prognostic indicator compared to s-QBC for identifying high- and low-risk patients for acute GBS UTI. Collectively, these findings indicate that age-based associations may be equally as useful as s-QBC for predicting infection category in the setting of adult patients with GBS-positive urine cultures.</p>
ISSN:1471-2334