Urinary tract infection (UTI) Dr. András Tislér April 2016
Complicated UTI Uncomplicated UTI Categories of urinary tract infections in adults 1. Acute uncomplicated cystitis in young women 2. Recurrent acute uncomplicated cystitis in young women 3. Acute uncomplicated pyelonephritis in young women 4. Acute uncomplicated cystitis in adults with possible occult renal or prostatic involvement Male, elderly, pregnancy, diabetes, recent urinary tract instrumentation 5. Complicated UTI 6. Asymptomatic bacteriuria Comprehensive clinical nephrology 2016
Complicated UTI Urinary tract abnormalities Structural: stone, stricture, obstruction, cysts, prostate hypertrophy Functional: neurogenic bladder, vesicoureteral reflux Foreign bodies Indwelling catheter, stent, nephrosomy Other conditions Immunocompromised patient Steroids, chemotherapy, transplanted Hospital aquired Risk for resistant strains Hospital aquired ABx within 30 days Symptoms more than 7 days
Uncomplicated v.s. complicated UTI Uncomplicated Lower risk of serious complications Usually no need to obtain urine culture Treatment usually empiric and shorter
UTI epidemiology UTI most frequent bacterial infections Incidence 0.7/py in college women, may recur in 20-30%, clustering occurs 0.07/ py in postmenopausal women In young males much less frequent, but above 50years incidence equals to that of woman by the age 32 50% of females had at least 1episode Needs special attention in children, males, diabetics, pregnant woman, elderly, those with indwelling catheter
Risk factors for UTI UTI usually occurs after urethral colonisation by enteral bacteria followed by ascending infection Hematogenous spread <2% (S. aureus, salmonella, some fungi) Bacterial virulence and host defence mechanisms play a major role Uncomplicated UTI (usually young female) Genetic factors, sexual intercourse, spermicide use, previous UTI, family Hx of UTI Complicated UTI
Comprehensive Clinical Nephrology 5th Ed 2016
Diagnosing UTI Patient history frequently sufficient to make the diagnosis of cystitis Urinalysis Urine dipstick Microscopy Urine culture Blood count and serum tests Radiology tests
Urine dipstick Diagnosing UTI: urinalysis Leukocyte esterase positivity Nitrite positivity (only enterobacteriaceae) If both tests are negative UTI is unlikely Not sufficient to rule out bacteriuria in pregnancy Blood, protein may be positive Urine microscopy Leukocyturia Leukocyte casts in pyelonephritis Red blood cells
Diagnosing UTI: urine culture Indications Not needed in uncomplicated cystitis in young woman Indicated in complicated UTI (+/- pyelonephritis in young woman) Atypical symptoms Failure to respond initial therapy Sampling First morning sample best Local desinfection (nonfoaming antiseptic), drying Spreading the labia - pulling back foreskin Midstearm sample In patients with catheter use new catheter Immediate culturing or store on +4 degrees
Diagnosing UTI: definition of positive culture Classically significant bacteriuria 10 5 CFU/ml If typical symptoms then lower counts are diagnostic (as low as 10 3 CFU/ml) Consider already treated patients with lower counts Urine culture typically grows monoflora unless Contamination during sampling and storage Fecal contamination of the bladder
Diagnosing UTI: blood tests in severe infection Blood culture may be positive Severe pyelonephritis, urosepsis Hematogenous spread CRP increased sedimentation increased (up to 100m/h in pyelonephritis) Leucosytosis with left shift
Comprehensive Clinical Nephrology 5th Ed 2016
Acute cystitis in adults In otherwise healthy adult woman: non complicated Signs/symptoms Dysuria, frequency, hematuria, no fever Suprapubic tenderness Diagnosis Dipstick leukocyte, nitrite positive Culture not necessary if typical clinical picture, but needed in recurrent infection, complicated UTI Dfferential diagnosis Urethritis, vaginal discharge, pelvic inflammation Complication Hemorrhgic cystitis Ascending infection-pyelonephritis
Short course treatment (3-5 days) Comprehensive Clinical Nephrology 5th Ed 2016
Recurrent uncomplicated cystitis in young women In young college students 27% experienced at least one recurrence, 2,7% a second recurrence Clustering occurs Usually same strain If recurrence within 1-2 weeks, urine culture may be needed Prophylaxis (behavioral) Avoid spermicides, postcoital voiding - fluid intake, cranberry products (not proven efficacy), wipe front-to back after defecation Postmenopausal: estrogen cream Antibiotic Continous: daily bedtime, or fosfomycine q10d Self-treatment: postcoital, TMP/SMX, nitrofurantoin
Complicated cystitis in adults Potential for serious complications Urine culture needed before commencement of empiric therapy, adjust treatment thereafter according to culture result Post treatment repeat culture is not needed except in pregnancy Early recurrence of cystitis in males suggests prostatitis (long term treatment is needed (4-6 weeks)
Acute pyelonephritis Only in young females may be considered uncomplicated Pathology: acute tubulointerstitial nephritis, tissue invasion Microbiology E. coli, Proteus, Klebsiella, Enterococcus, Enterobacter Usually no S. saprophyticus Signs symptoms Dysuria, hematuria, fever, lumbal pain, loin pain, nausea, vomiting Bacteriemia: 30% May lead to decreased kidney function
Acute pyelonephritis
Acute pyelonephritis Needs culture/sensitivity (unless uncomplicated) Needs hospitalisation if: Inability to take in enough fluid Non-compliance Progressive clinical picture Uncertain diagnosis Complications renal abscess Perirenal abscess Sepsis Papilla necrosis Chr pyelonephritis
Harrisons Internal Medicine 19th ed.2015 Comprehensive Clinical Nephrology 5th Ed 2016 Acute pyelonephritis
Pyelonephritis: empiric treatment (followed by targeted according to culture result) - INCREASE FLUID INTAKE (p.o., i.v.) (>2000cc/day urine) - Fluorokinolones first lin therapy in uncomplicated pyelonephritis (p.o. or i.v.) - 3. generation cephalosporin (e.g. ceftriaxone) - Oral beta lactams less effective - In case of more complicated cases: - imipenem-cilastatin, piperacillin tazobactam - Gentamycin - Duration - Uncomplicated: 7days - Complicated 10-14days
UTI in pregnant women Nitrofurantion, ampicillin, cephalosporins are safe Avoid fluorokinolones, sulfonamides Needs urine culture after treatment
Catheter associated UTI 15-25% of general hospital patients have urethral catheter at some point Incidence of bacteriuria is 3-10%/day! May lead to symptomatic UTI, bacteremia, urosepsis Asymptomatic bacteriuria is not to be screened for or treated in patient with catheter Risk of multidrug resistant strains
Asymptomatic bacteriuria Positive culture in a asyptomatic person (>10 5 CFU/ml) To be screened for and to be treated in: Pregnancy Vesico-ureteral reflux (VUR) before urological procedures struvite (staghorn) stone disease Renal transplant Treatment is not indicated in: Diabetes non pregnant women elderly spinal cord injury
UTI: fungal infections Susceptible Diabetic, immunocompromized, catheter, nephrostoma Primary Blastomyces, Coccidioides Secondary S&S Rx Oppurtunistic: Candida, Aspergillus, cryptococcus Less acute than with bacterial infections Fluconazole, itroconazole, amphotericin B
Harrisons Internal Medicine 19th ed.2015
Harrisons Internal Medicine 19th ed.2015
Harrisons Internal Medicine 19th ed.2015