Epidemiology of Nephrostomy Tube-Related Urinary Tract Infections among US Veterans

Objective The aim of this study was to review the incidence of asymptomatic bacteriuria (AB) and pyelonephritis after placement of percutaneous nephrostomy tube (NT) in our patients. Methods We retrospectively reviewed patients who underwent NT placement from January 1, 2005, to December 31, 2015, at Northport Veterans Affairs Medical Center. We identified patients with NT-associated AB and NT-related pyelonephritis within 60 days following NT placement. We analyzed demographic data, medical history, and microbiological data. Results Seventy-one patients underwent NT placement. Indications for NT placement included intrinsic obstruction (34%) and extrinsic obstruction (66%). Prostate and urinary bladder cancers were the most common causes of extrinsic obstruction. Twenty percent (14/71) had pyelonephritis, and 24% (17/71) had AB. All patients were men, and median age was 73 years. In the pyelonephritis group, Pseudomonas aeruginosa (36%) and Enterococcus faecalis (35%) were most commonly isolated. Three cases of extended-spectrum β-lactamase-producing Enterobacteriaceae and 2 multiple drug-resistant gram-negative organisms were identified. In the AB group, P. aeruginosa (23%), Enterococcus species (23%), and coagulase-negative staphylococci (23%) were most common. Only 1 case of extended-spectrum β-lactamase organism was identified. Comparing the 2 groups, there was no difference in age (P = 0358), diabetes mellitus (P = 0.441), chronic kidney disease (P = 0.6705), and prior urinary tract infection (P = 1.000). Presence of ureteral stent was seen more in AB (P = 0.057). Conclusions Nephrostomy tube placement was associated with pyelonephritis and AB in 44% of cases overall. Pseudomonas and Enterococcus species were the most common pathogens. Isolation of resistant organisms was mostly observed in the pyelonephritis group.