Treated asymptomatic bacteriuria during first year after renal transplantation

Background Urinary tract infections (UTIs) are widespread in renal transplant (RTx) recipients with asymptomatic bacteriuria (AB) as the predominant form. It is necessary to determine if AB is a risk factor for symptomatic UTIs. Methods We analyzed clinical data and urine cultures performed within the first 12months after RTx in 209 consecutive patients undergoing RTx at Gdask Transplantation Center between January 2007 and December 2009. Results We observed 170 AB episodes in 83 patients. This accounted for 53% of all diagnosed UTIs in 111 patients, with more than half of AB episodes occurring during the first month post transplant. The most prevalent uropathogen was Enterococcus faecium (36.8%, n=32) and, from the second month after RTx, Escherichia coli (54.2%, n=45). Female gender, use of induction with anti-thymocyte globulin, comorbidity measured by Charlson Comorbidity Index, history of acute rejection, and cytomegalovirus infection were risk factors for developing AB, and no differences in risk factors were seen for developing a symptomatic UTI vs. an AB after RTx. All patients with AB received antibiotic therapy. AB was an independent risk factor for symptomatic UTIs, but only 21 of 152 episodes of symptomatic UTIs were preceded by AB with the same causative agent. Conclusions AB is a common finding in the RTx population and AB episodes may be considered a risk factor for symptomatic infections. It remains to be determined if the treatment of AB in RTx patients is in fact helpful or harmful in preventing symptomatic infections.