The diagnosis of a urinary tract infection in infants is difficult because of limitations in specimen collection. Aseptic suprapubic bladder aspiration is the gold standard but is relatively invasive and often restricted to hospital use. More commonly in the office setting, clean-catch urine collection with a sterile urine bag is used. Ramage and associates assessed the diagnostic accuracy of performing cultures on urine obtained by the clean-catch technique compared with that collected by suprapubic aspiration.

Urine was collected by both techniques from 49 infants. Urine cultures were defined as positive in the presence of pure growth of 10,000 colony-forming units per mL in clean-catch specimens and the growth of any organisms in specimens obtained by suprapubic aspiration.

The perception that obtaining a urine specimen by means of the clean-catch technique is time-consuming and requires nursing supervision has limited the application of this technique. By giving parents careful instruction, the collection rate achieved by the parents in this study was more than 70 percent, with the majority of specimens obtained in less than one hour. The demonstrated sensitivity of clean-catch urine collection in this study was 88.9 percent.

The authors conclude that clean-catch urine collection is a reliable technique for obtaining urine specimens in infants, although supra-pubic aspiration remains the technique of choice for urine collection in the sick febrile infant for whom rapid initiation of therapy is appropriate.