Short-Term Outcome of Untreated Versus Treated Asymptomatic Bacteriuria in Renal Transplant Patients

Background. Infection of the urinary tract (UTI) is the most common form of bacterial infection in renal transplant patients, but its management is still controversial. We compared symptomatic and asymptomatic bacteriuria, treated or untreated, during two different months (summer or winter). Methods. This longitudinal, prospective study involved routine urine cultures collected during September 2014 or March 2015. Demographic, clinical, and microbiological characteristics from the patients with positive urine cultures were described. The main outcomes were the need of hospitalization, the bacterial clearance, and the selection of the resistant pathogen. Results. From the 538 urine cultures collected, only 61 were positive urine cultures. Twenty were untreated asymptomatic bacteriuria (AB), 28 were treated AB, and 13 were treated symptomatic bacteriuria. The more prevalent micro-organisms were E coli (27%), K pneumoniae (11%), and E faecalis (7%). There were no differences in the demographic, clinical, and microbiological characteristics depending on the month when the urine cultures were collected. Only 10 patients required hospitalization during follow-up, and all of them belonged to the treated group. Bacterial clearance after the treatment occurred in 20 patients of the 41 treated (48.9%) and spontaneously in 14 of the 20 patients untreated (70%). Of the treated patients, 47.6% developed a new resistance to another antibiotic. Conclusions. Only 7.6% of the routine urine cultures on renal transplant were positive. Untreated AB did not require hospitalization, and 70% had spontaneous bacterial clearance.