Urinary tract infection in oliguric patients with chronic renal failure

We studied 182 patients with chronic renal failure by urinalysis and urine cultures. Of the patients 27 per cent had significant bacteriuria (more than 10(5) per ml.), 38 per cent had significant pyuria (more than 10 white blood cells per high power field), 19 per cent had urinary tract infection and 7 per cent had symptomatic urinary tract infection. All 12 patients with symptomatic urinary tract infection had significant bacteriuria and 11 had significant pyuria, while 1 had 5 to 10 white blood cells per high power field. Incidences of urinary tract infection differed depending on the primary renal disease (12, 13, 41 and 67 per cent for chronic glomerulonephritis, diabetic nephropathy, polycystic kidney and chronic pyelonephritis, respectively). Among the patients with chronic glomerulonephritis no significant differences were seen in frequencies of bacteriuria and urinary tract infection between male and female patients or between those who did and did not undergo hemodialysis. Also, no significant correlation was seen between bacteriuria and daily urine output but pyuria was significantly more frequent in oliguric patients or those on hemodialysis.     

Utilization of extended donor criteria liver allograft: Is the elevated risk of failure independent of the model for end-stage liver disease score of the recipient?

BACKGROUND: The role of asymptomatic bacteriuria in kidney transplant recipients is unknown. There is no clear evidence of its effect on transplanted kidney. METHODS: We studied urine cytokines profile among kidney transplant recipients with bacteriuria found in screening examination. Urine cultures were collected in 269 patients with stable graft function and serum creatinine level <2 mg/dl, during their routine visits. Interleukin (IL)-6 and IL-8 levels were measured in urine samples from patients with asymptomatic bacteriuria, symptomatic urinary tract infection and patients without bacteriuria (control group). Changes in serum creatinine level in patients with asymptomatic bacteriuria and in the control group were observed during 12 months follow up. RESULTS: Urinary tract infection (UTI) was diagnosed in five patients and asymptomatic bacteriuria in 22 patients. Urine IL-6 level was significantly higher in symptomatic UTI group (median 15.71 pg/mg) but there were no differences between group of patients with asymptomatic bacteriuria (3.92 pg/mg) and control group (2.54 pg/mg). Urine IL-8 level was higher in symptomatic UTI group (median 146.8 pg/mg) and was also significantly higher in asymptomatic bacteriuria group (33.49 pg/mg) in comparison to control group (2.97 pg/mg; P=0.0002). During 1-year follow up, incidence of UTI was higher in the asymptomatic bacteriuria group than in the control group but graft function was not different in both groups. CONCLUSIONS: Elevated urine IL-8 level in kidney transplant patients with asymptomatic bacteriuria may reflect impaired immune response to bacterial infection and occult inflammatory process in urinary tract.     

Value of Routine Voiding Cystourethrography After Renal Transplantation

The impact of vesicoureteral reflux (VUR) on renal allograft outcomes is debatable, with small cohort studies reporting controversial results. The objective of this retrospective study was to evaluate long‐term clinical effects of early VUR in a large cohort of kidney transplant patients. Posttransplantation voiding cystourethrography was used to evaluate 646 consecutive kidney transplant recipients before discharge. The study endpoints included VUR grade, death‐censored graft or patient survival, renal function, proteinuria and occurrence of urinary tract infections (UTIs). Of the 646 recipients, 263 (40.7%) were diagnosed with VUR. VUR grade II was most common (19.8%), followed by grades III (10.2%), I (7.9%) and IV (2.8%). VUR was less common in transplantations performed by experienced compared to inexperienced surgeons (36% vs. 48%; p = 0.004). VUR did not affect death‐censored graft or patient survival and was not associated with proteinuria or occurrence of UTIs. Patients with VUR had a lower eGFR at 1 year after transplantation than did patients without VUR (60 vs. 52 mL/min/1.73 m²; p = 0.02), although this difference was not observed at 3 and 5 years after transplantation. We conclude that early VUR, a common finding among renal transplant patients, may not have a meaningful impact on long‐term transplant outcomes.     

High incidence of bacteriuria in early post-kidney transplantation; results from a randomized controlled study

Since the incidence of bacteriuria in kidney transplant recipients varyes according to the study, we examined it among our cases. Our post hoc analysis of data from a single-center, parallel, randomized, controlled, open label study included 90 patients who underwent kidney transplantation at our hospital from April 2010 to January 2011. Patients were randomized to early ureteric stent removal at 8 days versus routine ureteric stent removal at 15 days after kidney transplantation. We identified the incidence of and causative organism for bacteriuria in the early posttransplant period.Seventy-Four patients (58% living donors) participated in this study. The overall incidence of bacteriuria was 56.7% during the first month after kidney transplantation. In patients who had bacteriuria, 48% showed symptomatic urinary tract infection, 40% asymptomatic bacteriuria and 12% urosepsis. The most common organism was Escherichia coli (40%) follow by Klebsiella pneumoniae (19%). The incidence of an ESBL producing organism was 34%. The incidence of bacteriuria was high during the early post-kidney transplant period, requiring increased awareness and surveillance.     

Comparing two ureter reimplantation techniques in kidney transplant recipients

We compared the incidence of urological and anastomotic complications for the ureteroureterostomy and Lich-Gregoir techniques in kidney transplant recipients. Between May 2003 and February 2004, 75 kidney transplant recipients from living donors were divided into two similar groups to receive ureteroureterostomy (n = 41, 28 male, 13 female) and Lich-Gregoir techniques (n = 34, 24 male, 10 female) for ureteral reimplantation. Patients with vesicoureteral reflux (VUR) to the native kidneys were excluded from the study. The urological complications included complicated hematuria, ureteral stenosis, symptomatic VUR, recurrent urinary tract infection (UTI). There was no statistical significance between two groups in terms of gender, age, end-stage renal disease etiology, human leucocyte antigen (HLA) mismatch numbers, type and duration of dialysis, and cold ischemia time. The incidence of urologic and anastomotic complications was 12%. Complications in the Lich-Gregoir group included symptomatic VUR in 8.8% and stent migration in 2.9% of cases. Complications observed in the ureteroureterostomy group were ureteral stricture 7.3% and complicated hematuria in 4.9% of cases. However, symptomatic reflux was not observed in the ureteroureterostomy group. UTI frequency was similar in both groups. Ureteroureterostomy can be safely performed as a primary choice in kidney transplant recipients.     

Urinary Tract Infections in the First Year Post–Kidney Transplantation: Potential Benefits of Treating Asymptomatic Bacteriuria

Background

Urinary tract infections (UTIs) are the commonest infectious complication in kidney transplant recipients (KTRs). No recommendations exist regarding treatment of asymptomatic bacteriuria. We aimed to identify potential risk factors and microbiological profile for UTIs, the role of treatment of asymptomatic bacteriuria, and effects on graft outcomes of bacteriuria within the first year post-transplantation.

Bacteriuria and urinary tract infections in malnourished children

We prospectively examined the incidence of bacteriuria in malnourished patients between 6 months and 5 years of age. For each patient, a normally nourished control matched for age, sex, and presence of fever and diarrhea was included. Of 112 patients (65 boys), 55 had moderate and 57 had severe malnutrition; 43 had diarrhea and 35 had fever. Clean-catch and suprapubic urine specimens were examined microscopically and cultured. Significant bacteriuria was found in 17 (15.2%) malnourished and 2 (1.8%) control subjects ( P<0.01). The incidence of bacteriuria in malnourished and normally nourished subjects with fever was 28.6% and 5.7%, respectively ( P<0.05). The risk of bacteriuria increased significantly with the severity of malnutrition and in patients with diarrhea. Bacteriuria was associated with symptoms (70.6%) and elevated levels of acute-phase reactants (88.2%), indicating the presence of urinary tract infections (UTI) rather than asymptomatic colonization. Our observations show that malnourished children, particularly those with fever, are at risk for UTI. Urinalysis is useful for screening for UTI in these subjects. Urine culture should be performed in patients showing an abnormal urinalysis, and if the likelihood of detecting bacteriuria is high (as in patients with fever or diarrhea). Significant bacteriuria in malnourished subjects should be treated with appropriate antimicrobials.     

Urinary tract infection after urodynamic studies in women: incidence and natural history

OBJECTIVE: To study the incidence, natural history and symptomatic effects of bacteriuria after urodynamic studies in women. PATIENTS AND METHODS: In a prospective study in the urogynaecology clinic of a large District General Hospital, 214 women (mean age 52.3 years, range 23-81) underwent urodynamic studies. Bacteriuria was detected by semiquantitative culture at 2 and 7 days after the test. Women completed a 7-day diary of symptoms and events. RESULTS: The incidence of bacteriuria after urodynamic studies was 7.9%. Bacteriuria was transient in four of 17 women but persisted in nine and developed late in four; only one of 17 infections gave rise to symptoms. Irritative bladder symptoms after the test occurred in 34% of women, but only three went to their doctors because of concern about a possible urinary tract infection. Advancing age was the only variable associated with bacteriuria after urodynamic studies (P= 0.05). Menopausal status, past history of urinary tract infection, number of urethral instrumentations required, order number in a session, peak urinary flow rate and urodynamic diagnosis were not associated variables. CONCLUSIONS: In a large series of women presenting to a urogynaecology clinic, urodynamic investigations were associated with a high incidence of transient irritative symptoms but a low incidence of bacteriuria (8%). Infection was asymptomatic in most patients, but its natural history was unpredictable. Transient, persistent and late cases of bacteriuria all occurred. In this population, urodynamic studies are associated with a low level of morbidity.     

Strong inflammatory cytokine response in male and strong anti-inflammatory response in female kidney transplant recipients with urinary tract infection

Urinary tract infection (UTI) is the most common post-transplant infection in renal transplant recipients. The relationship of plasma and urine cytokines with UTI after kidney transplantation has not yet been delineated and literature reports on cytokine and UTI are rare. In a retrospective study, we compared post-transplant plasma and urine cytokine levels of 132 outpatient renal transplant recipients with or without UTI. Soluble interleukin-1 receptor antagonist (sIL-1RA), IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-8, IL-10, transforming growth factor-beta2 (TGF-beta2), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) levels were determined using commercially available enzyme-linked immunosorbent assay (ELISA) kits. We found gender-related urine cytokine patterns. Anti-inflammatory sIL-1RA was significantly higher in females than in males and this gender-related difference was more pronounced in bacteriuric (P < 0.0001) than in nonbacteriuric (P = 0.001) patients. Urine proinflammatory cytokines IL-6 (P = 0.001) and IL-8 (P = 0.007) were significantly higher in male patients with bacteriuria than in males without bacteriuria and sIL-2R (P = 0.001) and sIL-6R (P = 0.03) were significantly higher in males with leukocyturia than in males without leukocyturia. Bacteriuria in males was associated with higher doses of immunosuppressive drugs (P = 0.02). Male renal transplant recipients with UTI have a strong inflammatory cytokine response with activation of IL-6, IL-8, sIL-2R and sIL-6R producing cells, whereas female patients with UTI block the inflammatory response to UTI by production of sIL-1RA.     

Acute renal damage in infants after first urinary tract infection

Urinary tract infection (UTI) is one of the most common causes of unexplained fever in neonates. The aim of this study was to determine the incidence of urinary tract anomalies and acute renal damage in neonates who presented with first urinary tract infection in the first 8 weeks of life. We reviewed the records of 95 infants, who were hospitalised with UTI during a 6-year period (1994-1999). Patients with antenatally diagnosed hydronephrosis and incomplete radiological investigations were excluded from the study. Of the remaining 57 patients, 42 were boys and 15 girls. The mean age at diagnosis was 32 days (range 5-60 days). All patients underwent renal ultrasonography (US), voiding cystourethrogram (VCUG) and (99m)Tc-dimercaptosuccinic acid (DMSA) scan. Urinary tract abnormalities were detected in 20 (35%) patients. Vesicoureteral reflux (VUR) was found in 19 (33%) neonates, 7 girls and 12 boys. Acute cortical defects on DMSA scan were present in 19 kidneys of patients with VUR and in 25 of those without reflux. Only one-third of neonates after first symptomatic UTI had VUR. We recommend that US, VCUG, and DMSA scan should be routinely performed after the first UTI in infants younger than 8 weeks.     

Urinary tract infection and patient satisfaction after flexible cystoscopy and urodynamic evaluation

OBJECTIVES: To investigate the incidence of symptomatic and asymptomatic bacteriuria and to assess patient satisfaction after flexible cystoscopy (FC) and urodynamic (UD) evaluation in a prospective survey. The incidence of urinary tract infection after FC and UD studies and the use of prophylactic antibiotics are issues of debate. The tolerability and acceptance of FC and UD studies by patients have not been thoroughly documented. It would be helpful to be able to give such information to patients before performing these procedures. METHODS: A total of 215 nonconsecutive patients seen as outpatients for FC and UD studies to evaluate various indications were studied. A midstream urine sample was taken before and 48 hours after the procedures. Patients were given a questionnaire that inquired about the presence of lower urinary tract symptoms before and 48 hours after the procedures. The self-administered questionnaire included questions to assess patients' tolerance of the procedures and how it compared with their expectations. RESULTS: Of the 201 patients analyzed (FC 103, UD studies 98), 9 patients (4. 5%) developed significant bacteriuria within 48 hours of FC and UD studies. Only 2 patients with significant bacteriuria reported newly developed symptoms within 48 hours. In a subgroup of 25 patients who were given prophylactic antibiotics for various reasons, 6 (24%) reported new symptoms, although none developed significant bacteriuria. The association between patients who had preprocedure pyuria (n = 7) and the development of significant growth after the procedure (n = 6) was significant (P <0.01). In response to the patient-satisfaction questionnaire, 166 (82.5%) reported that the procedure was not as bad as they expected, and 200 (99.5%) said that they would undergo the test again if necessary. CONCLUSIONS: FC and UD studies are safe, well-tolerated procedures. The addition of prophylactic antibiotics in these procedures is unnecessary, unless specific indications are present.     

Pyuria: index of infection in patients with spinal cord injuries.

Little is known about the significance of pyuria in patients with spinal cord injuries. The progress in hospital of 55 such patients was studied. They were divided into 2 groups according to the method of bladder drainage on admission. Group A comprised 43 patients with indwelling catheters. Group B comprised 12 patients who were able to void with tapping, with/without compression and on intermittent catheterisation. The results showed that group A had a mean pyuria level of 185 WBC/HPF on admission. The incidence of urinary tract infection was 4 per patient during hospitalisation and the mean duration of bladder training was 82 days. Group B had a mean pyuria level of 32 WBC/HPF on admission. The incidence of urinary tract infection was 1 per patient during hospitalisation and the mean duration of bladder training was 40 days. The difference between groups A and B for all 3 parameters was statistically significant. These results suggest that patients with spinal cord injuries and indwelling catheters have a higher pyuria level and an increased risk of significant morbidity secondary to urinary tract infection, especially at the pyuria level of 100 WBC/HPF. A low pyuria level of less than or equal to 30 WBC/HPF was associated with a nil or low incidence of bacteriuria and urinary tract infection in our patients.     

Does pre-transplantation antireflux surgery eliminate post-renal transplantation pyelonephritis in children?

PURPOSE: Antireflux surgery for VUR before renal transplantation decreases the risk of post-kidney transplant UTI in pediatric patients with primary vesicoureteral reflux. We studied the risk of post-kidney transplant UTI in patients with or without surgical correction of VUR before transplantation compared to patients without VUR. MATERIALS AND METHODS: We compared 12 patients who had VUR corrected before transplantation (group 1) to 17 patients with VUR who did not undergo antireflux surgery before transplantation (group 2) and 36 patients undergoing renal transplantation without VUR (group 3). A total of 10 patients in group 1 (83.3%) and 10 in group 2 (58.8%) had high grade VUR. RESULTS: Eight patients in group 1 (66.7%), 6 in group 2 (35.3%) and 33 in group 3 (91.7%) remained free of febrile UTI during followup (p = 0.00). Among patients with high grade VUR 6 in group 1 and 1 in group 2 remained UTI-free (p = 0.02). A total of 33 patients in the control group (91.7%) remained free of febrile UTI, an incidence that was significantly lower compared to group 1 (p = 0.03) and group 2 (p = 0.00). Of the patients with high grade VUR 3 in group 1 (30%) and 4 in group 2 (40%) experienced recurrent febrile UTIs (p = 0.64). CONCLUSIONS: Even after surgical correction of VUR before transplantation the frequency of febrile UTI remained higher than that in kidney transplant recipients without VUR. In cases of high grade VUR reimplantation before renal transplantation decreased the rate of febrile UTI but it was still higher than the level of risk in the control group.     

Significance of immediate preoperative bacteriuria with pyuria in renal transplant recipients

The presence of bacteriuria and pyuria on urinalysis immediately before renal transplantation has resulted in cancellation of surgery because of concern about post-transplant wound infection. Of 113 renal transplant recipients reviewed 41 (36 per cent) had 5 or more white blood cells per high power field with bacteria in either a voided urine or bladder washout specimen obtained just before grafting. Of those 41 patients 2 suffered postoperative wound infections. Of 72 patients (64 per cent) with less than 5 white blood cells or no bacteria on a preoperative specimen 1 suffered a wound infection (p not significant by Fisher's exact test). Preoperative urine cultures and operative bladder cultures of all 3 patients failed to yield the organisms found later in the wound infections. The factors of sex, insulin-dependent diabetes, delayed graft function, living related versus cadaver donor and pre-transplant splenectomy had no significant relationship to wound infection rates. Renal transplantation can be performed safely in patients who have pyuria and bacteriuria but no signs or symptoms of infection.     

Endoscopic Treatment for Post-Transplant Vesicoureteral Reflux

IntroductionVesicoureteral reflux (VUR) is one of the most common ureteric complications after kidney transplantation that might cause symptomatic infections which deteriorate graft function. Surgical reimplantation has been the standard treatment; recently, endoscopic injection has been an alternative approach. We report our endoscopic treatment results and analyze the long-term outcome, even in patients with less optimal graft function.Materials and methodsA total of 16 patients and 19 symptomatic VUR were diagnosed at mean time of 88.3 months after their transplantation. The distribution of VUR grade was 1, 2, 8, 6, and 2 for grade I to V, respectively, with a mean VUR grade of 3.26 according to their voiding cystourethrogram images. Endoscopic Deflux injections were performed by a single urologist via rigid cystoscope with a beveled needle system. They were followed monthly thereafter.ResultThe average number of admissions due to symptomatic urinary tract infection was 2.68/person, and the mean creatinine level before endoscopic treatment was 1.63 mg/dL. The amount of Deflux injection was 0.7 to 1.2 mL per affected ureter; the mean creatinine level after endoscopic treatment was 1.41 mg/dL. The eGFR remained stationary in both eGFR > 60 and eGFR < 60 mL/min groups with a clinical success rate of 75% in both groups.ConclusionEndoscopic dextranomer-hyaluronic acid injection is a safe and feasible treatment option for VUR after kidney transplantation. Our data showed its efficacy in recipients whose eGFR is less than 60 mL/min.     

Bacteriuria, pyuria and bacteremia frequency following outpatient cystoscopy

AIM: The assumed necessity of antimicrobial prophylaxis prior to cystoscopy is controversial. In this study, the rate of bacteriuria, pyuria and bacteremia in outpatients who underwent cystoscopy without antimicrobial prophylaxis is investigated prospectively. METHODS: The study included 75 patients who underwent cystoscopy for various indications and had sterile urine prior to intervention. A clean midstream urine sample was obtained 24 h before and 48 h after the procedure. Blood cultures were taken 1 h after cystoscopy. Patients were questioned for newly developed symptoms 48 h after cystoscopy. Blood cultures were taken again from patients who presented with fever. RESULTS: Six patients (8%) developed significant bacteriuria, and six patients (8%) developed pyuria without significant bacteriuria. Bacteremia was not determined in any of the patients. The association between presence of pyuria prior to the procedure and development of bacteriuria after the procedure was significant (P < 0.05). Four patients out of six who had bacteriuria were asymptomatic. In our study we found significant bacteriuria after cystoscopy in 8% of patients, and no bacteremia. CONCLUSIONS: Thus we conclude that cystoscopy is a safe and well-tolerated procedure. Antimicrobial prophylaxis should not be administrated unless specific indications are present.     

Antimicrobial prophylaxis for transrectal prostatic biopsy: a prospective study of ciprofloxacin vs piperacillin/tazobactam

OBJECTIVE: To compare the efficacy of short-term parenteral prophylaxis with piperacillin/tazobactam (P/T) with long-term oral prophylaxis with ciprofloxacin in preventing infective complications after transrectal prostatic biopsy (TPB). PATIENTS AND METHODS: Patients scheduled for TPB were randomized to receive P/T (2250 mg intramuscular) twice daily for 2 days (Group 1), or ciprofloxacin (500 mg orally) twice daily for 7 days (Group 2), beginning on the evening before the procedure in both groups. All patients received a 100-mL phosphate enema 3 h before TPB. Evaluation included self-recording of body temperature in the 3 days after TPB, and culture of mid-stream urine (MSU) samples taken before and 3 and 15 days after TPB. Patients with indwelling urethral catheters or taking antibiotics or immunosuppressive drugs were excluded, as were patients with positive MSU cultures before TPB. RESULTS: Of the 138 evaluable patients, 72 received parenteral P/T and 66 oral ciprofloxacin. Bacteriuria (> 105 c.f.u./mL) after TPB occurred in two of 72 (2.8%) patients in Group 1 and in three of 66 (4.5%) patients in Group 2; this difference was not statistically significant (P > 0.1). However, of the five patients with bacteriuria, two were symptomatic and both were in Group 2. Pyrexia occurred in only one patient in Group 2 with symptomatic urinary tract infection, and required hospitalization. No other patient reported a body temperature openface> 37.5 degrees C or drug-related side-effects. CONCLUSIONS: This prospective study showed that short-term prophylaxis with P/T was associated with a low rate of asymptomatic bacteriuria, requiring no further treatment, whereas although the rate was similar on long-term prophylaxis with ciprofloxacin patients required further treatment, with one needing hospitalization. We recommend short-term prophylaxis with P/T despite its disadvantages of cost and parenteral administration.     

Clinicopathological study of vesicoureteral reflux (VUR)-associated pyelonephritis in renal transplantation

Abstract:  We retrospectively studied the occurrence of vesicoureteral reflux (VUR)-associated pyelonephritis using renal biopsies obtained from the transplanted kidneys, and correlated the histological changes with clinical parameters. Out of a total of 131 renal biopsies performed between 1990 and 2001 on renal transplant patients at the department of Urology of Nagasaki University Graduate School of Biomedical Sciences, 12 patients showed pyuria more than twice in a single year. Seven of these 12 patients were available for determining VUR by voiding cystourethrography (VCUG). Cystoureterography demonstrated VUR in three of seven studied patients with pyuria. A histopathological examination revealed dilatation of both proximal and distal tubules in renal biopsies of transplant patients with VUR, compared to renal biopsies of transplant patients without VUR, or non-transplanted patients with thin membrane disease. One of the patients with VUR showed advanced features of chronic pyelonephritis in four consecutive biopsies at different time points, suggesting a late stage of reflux nephropathy in the transplanted kidney. We conclude from our study that the occurrence of VUR-related pyelonephritis may be one of the important long-term complications in the survival of renal allografts.     

Urinary tract infection associated with urinary calculi. 1. The significance of urinary tract infection in urinary calculi

We investigated 158 cases of urinary stones (infection stones 56, metabolic stones 102) with special reference to pyuria, bacteriuria, stone culture and urease activities of isolated bacteria. Abacterial pyuria was noted in 9 out of 49 (18%) infection stones and in 53 of 77 (69%) metabolic stones. Bacteriuria was noted in 79% of the infection stones and 26% of the metabolic stones. Sixty-seven percent of the infection stones were infected with mainly urea splitting bacteria such as Proteus mirabilis and Staphylococcus. Twenty-three percent of metabolic stones were also infected. Though E. coli, a non-urea splitting bacteria, was isolated most frequently from metabolic stones, urease positive Staphylococcus and Pseudomonas were also isolated. Bacteria within stones could be predicted on the basis of urine culture results of only 20 of 41 infection stones and 8 of 24 metabolic stones. These facts are useful for selection of some antibiotics in the treatment of urinary tract infections associated with urinary calculi. Urinary infections of urea splitting bacteria in infection stones are thought to be initial factors of stone formation and those of non-urea splitting bacteria are to be superimposed. However, urea splitting bacteria in metabolic stones may convert them into infection stones in future.     

High incidence of bacteriuria following renal transplantation in children

Background. Bacteriuria is common post-transplant. However, most studies are in adults with a short follow-up. We have assessed the incidence of bacteriuria, predisposing causes and its effect on short and long-term graft function in children. Methods. The notes of 142 children (67% male) who received 168 kidney transplants (138 cadaveric) between 1987 and 1994 were studied. The mean age at transplantation was 9.0±4.5 years, and 32 children were transplanted pre-emptively. Diagnoses reflected those found in any children's renal failure programme. Results. Two hundred and thirty one episodes of bacteriuria were detected in 66 patients (46%): a rate of one episode per 23 patient months of follow-up. Fifty two per cent were during the first year, and 29% of these during the first 4 weeks post-transplant. Forty two children (28%) had recurrences. The incidence was not affected by sex, vesico-ureteric reflux into native kidneys, donor source, circumcision in boys, dialysis pre-transplant or acute rejection. Bacteriuria was significantly more common in patients with a history of bacteriuria before transplant (P<0.005) and with bladder pathology (P<0.001). Organisms were predominantly coliforms (41%); 70% were Gram-negative. Sixty percent were resistant to the prescribed antibiotic prophylaxis. There was an associated transient rise in plasma creatinine concentration: mean pre-episode 111±86 &mgr;mol/l vs mean post-episode 134±108 &mgr;mol/l (P<0.0001). Seventy two percent of episodes were asymptomatic, but even in this group 81% had an associated rise in plasma creatinine (P<0.001). Despite this, there was no significant decrease in glomerular filtration rate in patients with bacteriuria compared with patients without at the end of follow-up: 50 vs 56 ml/min/1.73 m² respectively. Conclusion. Bacteriuria is common post-transplant, occurring most often in those with bladder pathology or with a history of bacteriuria pre-transplant.