The Clinical Usefulness of a Repeat Urine Culture 48 Hours after Antimicrobial treatment in Anatomically Normal and Abnormal Urinary Tract Infection

Park, Kyung Hee; Yeom, Jung Suk; Park, Ji Suk; Park, Eun Sil; Seo, Ji Hyun; Lim, Jae Young; Park, Chan Hoo; Youn, Hee Shang

Abstract

PURPOSE: We aimed to compare the frequency of positive repeat urine cultures 48 hours after antimicrobial treatment between anatomically normal and abnormal urinary tract Infection (UTI) groups to determine the potential clinical usefulness of the tests.
METHODS
We reviewed medical records of 930 patients under age 14, who had been admitted for UTI at Gyeongsang National University Hospital from January 1, 1998 to August 1, 2008. The eligible patients were divided into two groups the anatomically normal UTI group and the anatomically abnormal UTI group. Statistical analyses were performed with variables consisting of the sex ratio, age distribution and the frequency of positive repeat urine cultures of each group.
RESULTS
The sex ratio of the anatomically normal UTI group was M:F=1.9:1, whereas that of the anatomically abnormal UTI group was M:F=3.5:1 (P=0.019). For age distribution, it was found that the mean age of the anatomically normal UTI group was 0.82+/-1.83 years, whereas that of the anatomically abnormal UTI group was 1.18+/-2.57 years (P=0.113). The frequency of positive repeat urine cultures in the anatomically normal UTI group was 3/279 (1.1%), whereas that of the anatomically abnormal UTI group was 1/90 (1.1%) (P=0.675).
CONCLUSION
We conclude that performing a repeat urine culture is not justified in terms of clinical usefulness, and it is unreasonable to use the results as an index of therapeutic success. A follow-up urine culture is unnecessary in patients with both the anatomically normal and abnormal UTI group.