URINARY TRACT INFECTION

Syakib Bakri, Hasyim Kasim, Haerani Rasyid

*Division of Nephrology, Department of Internal Medicine Faculty of Medicine, Hasanuddin University

Urinary Tract Infections (UTI)Frequent clinical problem

Any site in the urinary tract may be involved : the urethra, prostate, bladder, ureter, kidney and perinephric space.

Bacterial infection is most common, but fungi, chlamydia, viruses and parasites may be responsible in some patients

Women >>> Men

Terminology of Urinary Tract Infections (1)Bacteriuria : Presence of bacteria in the urine. Asymptomatic bacteriuria : 105 CFU/ml urine with or without pyuria, in a patient without symptoms of UTI.Cystitis : inflammation of the bladder Bacterial cystitis Abacterial cystitis (urethral syndrome)Acute pyelonephritis: acute bacterial infection of the kidney characterized by chills and fever (often high) and flank pain (usually unilateral), as well as tenderness.Ribeiro RM, et al. Int Urogynecol 2002;13:198-199.Chronic pyelonephritis : Radiological diagnosis where there is evidence of focal scarring of the kidneys with associated calyceal abnormality indicating renal damage due to a combination of reccurent infection with obstruction of the pelviocalyceal system (chronic obstructive nephropathy) or vesicoureteral reflux (reflux nephropathy).

Reinfection : An infection with a different strain of microorganism or a different serological type after (end of therapy) eradication of previous infection.Most likely represent infections of the bladder, occur weeks to months after treatment of the previous infection, response well to therapy, usually associated with a normal urinary tractRelapse : A consecutive urinary infection caused by the same strain or serotype of bacteria, usually represent infection of the kidney or prostat, often recur within 1 6 weeks after antimicrobials have been discontinued, some cases represent persistent infection, anatomic abnormalities or renal insuficiency are more common with relapsing or persistent infection, a long course of antimicrobials or surgery may be required if the urine is to be permanently sterilized Ribeiro RM, et al. Int Urogynecol J 2002;13:198-199.Terminology of Urinary Tract Infections (2)

Recurrent UTI: patients with at least two infections within 6 months or three or more during a single year, in which the initial episode is resolved and is followed by another infection.Ribeiro RM, et al. Int Urogynecol J 2002;13:198-199.Terminology of Urinary Tract Infections (3)Persistence : the continued presence of the microorganisms isolated at the beginning of the treatment, owing to resistance to antimicrobial therapy, inadequate drug dosage, or a urological abnormality. These unresolved infections may be also in consequence of the patients non-compliance in taking medication, mixed infections with two different bacterial strains with mutually exclusive susceptibilities, or renal insufficiency (leading to an inadequate drug concentration in the urine).

Diagnosis Urinary Tract InfectionSymptoms :Lower UTI : Frequency, dysuria, suprapubic painUpper UTI : Fever, flank pain, and chills as well as symptoms similar to bladder infectionUrinalysisCulture The presence of 10 WBC / mm3 fresh un-spun midstream urine The presence of 10 WBC / high-power field sediment midstream urine Radiological evaluation Ultrosound Plain abdominal radiography Intravenous urography CT scanning

Criteria for diagnosis of significant bacteriuriaSymptomatic women : 102 coliform organisms/ml urine plus pyuria, or 105 of any pathogenic organism/ml urine, or Any growth of a pathogenic organism from urine obtained by suprapubic aspiration

Symptomatic men : 103 pathogenic organism/ml urine Asymptomatic patients : 105 pathogenic organism/ml urine in two consecutive samples

Classification of Urinary Tract Infection (1)II. Upper urinary tract infection ( Pyelonephritis )I. Lower urinary tract infection ( Cystitis )Fever, flank pain, and chills as well as symptoms similar to bladder infectionFrequency, dysuria, suprapubic pain

I. Uncomplicated urinary tract infection Occurs in individuals with structurally and functionally normal genitourinary tracts Most common bacterial infection that occurs in women, but is uncommon in men May involve the bladder or the kidneys and may be symptomatic or asymptomaticII. Complicated urinary tract infection As acute or chronic parenchymal infection associated with a functional or structural urinary tract abnormality e.g. : Neurogenic bladder, urinary tract obstruction, immunocompromized patients, diabetes mellitus, polycystic kidney disease, renal transplant recipient. Classification of Urinary Tract Infection (2)

Bacterial etiology of urinary tract infection E. coli : 70-95% (uncomplicated UTI), 21-54% (complicated) S. Saprophyticus : 5-20% (uncomplicated), 1-4% (complicated) Enterococci : 1-2% (uncomplicated), 1-23% (complicated) Proteus mirabilis : 1-2% (uncomplicated ), 1-10% (complicated) Klebsiella spp : 1-2% (uncomplicated), 2-17% (complicated) Pseudomonas aeruginosa :

Clinical Classification of Urinary Tract InfectionAcute uncomplicated cystitis in womenAcute uncomplicated pyelonephritis in womenComplicated UTI in both sexesRecurrent infections in womenAsymptomatic bacteriuriaMcBryde C, Redington. Primary Care Case Rev 2001 ; 4 : 2

Single dose or 3-day course of treatment(trimethoprim sulfamethoxasole, quinolone, amoxycillin)Acute uncomplicated cystitis in womenFollow-up urine culture 7-14 days laterCured(sterile urine)Failure or relapse(identical pathogens)Reinfection(new pathogen)No investigationUltrasonography urinary tractKUB radiographCatel WR. Clin Drug Invest 1995 ; 9 (suppl 1) : 8-13.Treatment for 2 weeks

Clinical Classification of Urinary Tract InfectionAcute uncomplicated cystitis in womenAcute uncomplicated pyelonephritis in womenComplicated UTI in both sexesRecurrent infections in womenAsymptomatic bacteriuriaMcBryde C, Redington. Primary Care Case Rev 2001 ; 4 : 2

Moderate severitySevere illnessOutpatients and oral therapy possible(trimethoprim sulfamethoxasole, quinolone, amoxycillin)Treatment 14 daysHospitalization with initial parenteral therapy (trimethoprim-sulfametaxazol, ceftriaxone, quinolone, gentamicin with/without ampicilinOral treatment 14 days or longer as requiredAcute uncomplicated pyelonephritis in womenNo resolution in 5 daysNo resolution in 5 daysUrologic evaluationRadiologic evaluationResolution in 5 days

Clinical Classification of Urinary Tract InfectionAcute uncomplicated cystitis in womenAcute uncomplicated pyelonephritis in womenComplicated UTI in both sexesRecurrent infections in womenAsymptomatic bacteriuriaMcBryde C, Redington. Primary Care Case Rev 2001 ; 4 : 2

Hospitalize, urine culture, blood cultureEmpiric therapy with parenteral regimenSignificant clinical improvement YesNoSwitch to or continue oral regimen For total 2 weeks Review antimicrobial susceptibility patternRadiologic & urologic evaluationCorrect reversible risk factorsReview treatment plan as appropriate, treat for total 2 weeks or longers if necessaryFollow-up urine culture after treatment Complicated UTI in both sexes5 Days

Clinical Classification of Urinary Tract InfectionAcute uncomplicated cystitis in womenAcute uncomplicated pyelonephritis in womenComplicated UTI in both sexesRecurrent infections in womenAsymptomatic bacteriuriaMcBryde C, Redington. Primary Care Case Rev 2001 ; 4 : 2

Recurrent infections in womenReccurent UTI in womenDiagnosisRelapseReinfectionConventional antibiotic therapy 2-6 weeks 3 year 2 yearSexually activePostmenopausalConventional antibiotic therapy 3-7 daysEstrogen substitution (oral & topical)Antibiotic therapy : On demand orLongterm prophylaxisAntibiotic therapy :On demand orPostcoital orLongterm prophylaxis Madersbacher S, et al. Curr Opin Urol 2000 ; 10 : 32.

Drug regimens for long-term, low-dose prophylaxis of recurrent urinary tract infection* Treatment is effective if taken each night, alternate nights, three times a week, or just after intercourse

DrugDose*Nitrofurantoin50 mgTrimethoprim100 mgCo-trimoxazole0.24 gNorfloxacin200 mgCiprofloxacin125 mgCephalexin125 mg ( useful if renal insufficiency)Hexamine hippurate1 g

Clinical Classification of Urinary Tract InfectionAcute uncomplicated cystitis in womenAcute uncomplicated pyelonephritis in womenComplicated UTI in both sexesRecurrent infections in womenAsymptomatic bacteriuriaMcBryde C, Redington. Primary Care Case Rev 2001 ; 4 : 2

Indication for the treatment of patients with asymptomatic bacteriuriaRaz R. Nephrol Dial Transplant 2001 ; 16 (suppl 6) : 135.

DefinitivePossibleNot indicatedPregnancyDiabetes mellitusElderlyBefore an invasive genitourinary procedureShort-term indwelling catheterization

Intermittent catheterizationSchool girls and premanopausal women

Children with refluxRenal transplantLong-term indwelling catheterPatients with abnormal urinary tract

Indication for imaging studies in patients with Urinary Tract InfectionsInfections in a newbornReccurent infection occuring in childhoodTwo or more infections in adult femalesOne infection in adult malesElevated creatinine levelHistory of urinary calculiNeurologic bladder dysfunctionPersistent hematuriaPrevious genitourinary surgeryProlonged fever after initiation of antibiotic therapyRelapsing infectionUrea-splitting organismsUnusual causative organism

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