Urinalysis Accuracy for Diagnosis of Bacteremic Urinary Tract Infections in 0-3-Month-Old Infants.

AIM: To assess urinalysis (UA) accuracy for the diagnosis of bacteremic urinary tract infections (UTI) in young infants.

METHODS

A multi-center retrospective study collecting 2008-2022 data of infants 0-3-month-old with bacteremic UTI (same pathogen in urine and blood).

RESULTS

Of 110 infants with bacteremic UTI, 64% were male and the median age was 21 days; 85% were ≤ 2 months of age. Fever ≥ 38°C was evident in 80% and 2% had hypothermia. Gram-negative bacteria were cultured in 96%, E. coli in 72%, and Klebsiella in 18%. A total of 19 of the 110 infants (17%) had a normal UA (negative leukocyte esterase and negative nitrites). The sensitivity of abnormal UA for UTI diagnosis was 83% (95% confidence interval 76%-90%); 95% of the normal UA group had Gram-negative pathogens: E. coli in 58% and Klebsiella in 26%. In comparing infants with abnormal and normal UA, no differences in age, sex, rate of febrile infants, and pathogens were noted.

CONCLUSIONS

The accuracy of UA for identification of 0-3-month-old infants with bacteremic UTI is limited. Bacteremic UTI with a normal UA occurred in both genders, various ages, and pathogens. Relying solely on UA for ruling out UTI in 0-3-month-old infants may lead to significant underdiagnosis with a potential increase in morbidity.