Relationship Between Pyuria and Bacteriuria in Suspected Cases of Urinary Tract Infection

Abstract

Background: Urinary tract infection is one of the most common infections encountered worldwide and is a major public health problem. Urinary tract infection is diagnosed based on clinical features, pyuria and bacteriuria. The aim of this study was to determine the relationship between pyuria and bacteriuria in patients with suspected cases of urinary tract infection at Tribhuvan University and Teaching Hospital, Kathmandu.
Methods: A cross-sectional descriptive study was carried out from September to December 2023 in the Department of Microbiology at Tribhuvan University and Teaching Hospital. One thousand urine specimens were collected by the convenience sampling method from patients with suspected urinary tract infection and processed for routine macroscopic and microscopic examination followed by culture. The organisms were identified by standard microbiological methods as described by American society for Microbiology. Chi-square test was used wherever applicable with a p value<0.05 regarded as statistically significant.
Results: Out of 1000 urine specimens examined, pyuria was seen in 331(33.1 %) specimens. Among the 331 urine samples with pyuria, 137 (41.3 %) urine samples showed significant bacterial growth. Out of 669 urine specimens without pyuria, 33 (4.9%) showed significant bacterial growth. Escherichia coli was the most common organism causing urinary tract infection both with pyuria (71/98, 72.4%) and without pyuria (27/98, 27.6%). Culture positivity increased with the rising number of pus cells in the urine. This correlation between pus cell counts and culture positivity is statistically significant (p < 0.001).
Conclusions: Pyuria and significant bacteriuria may not always correlate in suspected cases of urinary tract infection. However, as the number of pus cell increases in microscopic examination of urine per high power field, the likelihood of getting urine culture positive result also increases.
Keywords: Bacteriuria; culture; pyuria; urinary tract infection.