Affiliations: Department of Neonatology, The Children's Hospital
Medical Center, Faculty of Medicine, Tehran University of Medical Sciences,
Tehran, Iran | Department of Pediatric Nephrology, The Children's
Hospital Medical Center, Faculty of Medicine, Tehran University of Medical
Sciences, Tehran, Iran | Department of Infectious Disease, The Children's
Hospital Medical Center, Faculty of Medicine, Tehran University of Medical
Sciences, Tehran, Iran
Note: [] Correspondence: Dr. Neamatollah Ataei, Department of Pediatric
Nephrology, The Children's Hospital Medical Center, Faculty of Medicine, Tehran
University of Medical Sciences, Dr. Gharib St. Azadi Avenue, 14194 Tehran,
Iran. Tel.: +98 21 66929234; Fax: +98 21 66930024; E-mail:
[email protected]
Abstract: Obtaining uncontaminated urine samples are important to diagnosis
urinary tract infection in neonates. The present study was designed to compare
urine contamination rates in two common methods of urine collection: urine bag
versus suprapubic aspiration. In a cross-sectional study, 119 consecutive
infants (aged 3 to 28 days) with fever who were referred to Children's Hospital
Medical Center in Tehran between September 2004 and March 2005 were included.
Urine was collected simultaneously by bag and suprapubic aspiration. The urine
samples were analyzed and bacterial cultures performed using standard
bacteriologic techniques. The rate of culture contamination differed markedly
according to the method of urine culture. Suprapubic aspiration specimens were
sterile in 92.4%. Pathogenic bacteria were isolated in 7.6%. No bacterial
isolates were deemed to be contaminants. Only 8.5% of bag specimens were
sterile. Of non-sterile cultures, 36.9% of bacterial isolates were deemed to be
pathogenic and 54.6% contaminants (P < 0.001 vs. suprapubic aspiration).
Pyuria (P = 0.002) and bacteriuria (P < 0.001) were more frequent in
specimens obtained by bag than urine from suprapubic aspiration. The existence
of a urinary tract anomaly was the main predictor for a positive culture in
urine obtained by suprapubic aspiration. Contamination rates and rates of
pyuria and bacteriuria are remarkably higher for urine obtained by bag
specimens than for urine obtained by suprapubic aspiration.
