UrinaryTractInfection尿路感染全英文課件

1、UrinaryTractInfectionWuYitaiDepartmentofNephrologyTongjiHospital,TongjiUniversityUrinaryTractInfectionContentDefinitionsEpidemiologyEtiologyPathogenesis PathologyClinical presentation DiagnosisTreatmentsComplicationPreventionContentDefinitionsDefinition of UTIUTI is defined as the presence of micro-

2、organisms in the urinary tract. Most patients with UTI have significant bacteriuria, i.e. bacterial colony counts 105 /ml, in a mid-stream “clean catch” urine. Conversely, colony counts 105/ml of midstream urine are occasionally due to specimen contamination.Acute urethral syndrome: dysuria, urgency

3、, and frequency, but without bacteriuria.Definition of UTIUTI is defiAnatomicLower UTI:urethritiscystitis(mucosal infection)Upper UTI:pyelonephritisprostatitisintrarenal and perinephric abscesses (tissue invasion)Classification of UTIs（1）AnatomicClassification of UTIsClassification of UTIs（2）Clinica

4、lUncomplicated UTI:Lack structural or functional abnormalities of the urinary tractNormal flow of urineNO interference with the normal defensesComplicated UTI:Predisposing lesion of the urinary tract, structural or functional abnormalities, e.g. congenital abnormality of the urinary tract, stone, ob

5、struction, catheter.Interference with the normal defenses, e.g. immunosuppression, renal disease, or diabetes.Classification of UTIs（2）CliniClassification of UTIs（3）EpidemiologyCatheter-associated（nosocomial）infections: Symptomatic Asymptomtic Non Catheter-associated（community-acquired）infections:Sy

6、mptomatic AsymptomticClassification of UTIs（3）EpidEpidemiologyAlmost half of all women will have at least one UTI in their lives.UTI is uncommon in men under the age of 50, but very common among women.Asymptomatic bacteriuria is more common among elderly men and women. EpidemiologyAlmost half of all

7、Etiology（1） Community-Acquired UTIgram-negative bacilli is the most common agentE. coliEnterobacterEnterococcusProteusStaphylococcus KlebsiellaE. coliEtiology（1） Community-AcquiredEtiology（2） Causative organisms: Escherichia coli Klebsiella, proteus and pseudomonas 1- Bacteria S. aureus, Staphylococ

8、cus epidermidis and S. saprophyticus Enterococci (Streptococcus faecalis糞鏈球菌) Mycobacterium tuberculosis Chlamydia trachomatis, Neisseria gonorrhoeae 2- Virus Herpes simplex virus , HIV 3- Fungus Candida, Histoplasma capsulatum 4- Protozoon Trichomonas vaginalis, Schistoma haematobium Etiology（2） Ca

9、usative organCASE 1 32 year-old woman;Dysuria and frequency; Pyuria in the urine sediment;Gram negative bacilli. Escherichia coli (E. coli) . CASE 2 65 year-old woman;Dysuria and frequency; Pyuria; Gram positive cocci. Enterococcus faecalisCASE 1 CASE 2 CASE 318 year-old woman Dysuria and frequency;

10、Pyuria; Gram positive cocci;Staphylococcus. CASE 4 42 year-old diabetic woman with a catheter. Gram positive yeasts. Candida grew.CASE 3 CASE 4 Route of InfectionAscending route (the most common)Colonization of urethraRoute of InfectionAscending roPathogenesisPathogenesisPathogenesis（1）The urinary t

11、ract above the urethra is normally sterile.The urethral meatus and surrounding perineum are colonized with a mixture of skin and bowel flora.Vaginal flora or pathogens may contaminate the urethra.Pathogenesis（1）The urinary traPathogenesis （2）Host defense mechanisms:1. Urine: low pH, high osmolality,

12、 high urea & organic acid concentration inhibit and kill microorganisms2. Regular urine flow: dilute and expel pathogens3. Bladder epithelial cells: coated with mucus (glycosaminoglycan) prevent bacteria from adhering to bladder wallPathogenesis （2）Host defense Conditions affecting pathogenesisGende

13、r and sexual activity. Pregnancy.Obstruction. （tumor, stricture, stone, BPH）Neurogenic bladder dysfunction.Vesicoureteral refluxBacterial virulence factorsGenetic factors（details in the following）Conditions affecting pathogeneConditions affecting pathogenesis（1）Gender and sexual activity The female

14、urethra appears to be prone to colonization with colonic gram-negative bacilli because of its proximity to the anus, its short length , and its termination beneath the labia. Voiding after intercourse reduces the risk of cystitis.An important factor predisposing to bacteriuria in men is urethral obs

15、truction due to prostatic hypertrophy. Conditions affecting pathogeneConditions affecting pathogenesis（2）PregnancyUTIs are detected in 2 to 8% of pregnant women.Pregnant women with asymptomatic bacteriuria.Bladder catheterization during or after delivery causes additional infections.Conditions affec

16、ting pathogeneConditions affecting pathogenesis（3）Obstruction TumorStrictureStoneBenign prostatic hypertrophy (BPH)These conditions result in hydronephrosis and increase frequency of UTI.Conditions affecting pathogeneConditions affecting pathogenesis（4）Neurogenic Bladder DysfunctionInterference with

17、 bladder enervation, as in spinal cord injury, multiple sclerosis, diabetes.The infection may be initiated by the use of catheters for bladder drainage.The infection is favored by the prolonged stasis of urine in the bladder.Conditions affecting pathogeneConditions affecting pathogenesis（5）Vesicoure

18、teral RefluxVesicoureteral reflux occurs during voiding or with elevation of pressure in the bladder.Common among children with anatomic abnormalities of the urinary tract.Renal damage correlates with marked reflux, not with infection. Conditions affecting pathogeneConditions affecting pathogenesis（

19、6）Bacterial Virulence factorsSpecific O, K, and H serogroups.Adherence of bacteria to uroepithelial cells is a critical first step in the initiation of infection. Fimbriae mediate the attachment of bacteria to specific receptors on epithelial cells.E. coli strains usually produce hemolysin and aerob

20、actin.Conditions affecting pathogeneConditions affecting pathogenesis（7）Genetic factorsHost genetic factors influence susceptibility to UTI.The number and type of receptors on uroepithelial cells are in part genetically determined. Conditions affecting pathogeneConditions affecting pathogenesisGende

21、r and sexual activity. Pregnancy.Obstruction. （tumor, stricture, stone, BPH）Neurogenic Bladder Dysfunction.Vesicoureteral RefluxBacterial Virulence factorsGenetic factorsConditions affecting pathogenePathologyCystitisMucosal hyperemiaEdemaLeukocyte infiltrationEasy bleedingGranular surfaceSuperficia

22、l ulcerPurulent exudatePathologyCystitisMucosal hypePathologyAcute PyelonephritisAcute inflammationHyperemia and edemaVolume increase Red colour Yellowish abscess Purulent exudatePathologyAcute PyelonephritisPathologyChronic PyelonephritisChronic inflammationPelvis deformed Cortex scarsVolume shrink

23、 Asymmetric Parenchyma atrophyPathologyChronic PyelonephriPathologyInterstitial edema Neutrophil infiltration White blood cell castIn microscopyPathologyInterstitial edema Clinical PresentationClinical PresentationClinical presentation（1）CystitisBurning painFrequency, urgencySuprapubic painDysuriaCl

24、inical presentation（1）CystitClinical presentation（2）Urethritis Burning painFrequency, urgencyDysuriaInfected with sexually transmitted pathogens Clinical presentation（2）UrethrClinical presentation（3）Acute PyelonephritisAll cystitis symptoms（+）or（-）Fever, shaking chillsNausea, vomiting, diarrheaTachy

25、cardia, hypotentionMuscle tendernessCostovertebral angle（CVA） painGram-negative sepsis , LeukocytosisLeukocyte casts in the urineClinical presentation（3）Acute Clinical presentation（4）Catheter-Associated UTIs Bacteriuria develops in at least 10 to 15% of hospitalized patients with indwelling urethral

26、 catheters.The risk of infection is 3 to 5% per day of catheterization. Many infecting bacteria display markedly great antimicrobial resistance.Clinical presentation（4）CathetHow is it diagnosed?DiagnosisPatient history Complete physical examination Urine culture Urine analysis Other examinations How

27、 is it diagnosed?DiagnosisPMicroscopic ExaminationPyuria WBC 5 / HPBacterial colony counts 105 / mlDiagnosisMicroscopic ExaminationPyuria DiagnosisDipstick MethodsLeukocyte esterase +Nitrite + Urine routine: pH, sg, protein, glucose, blood, ket, etc.DiagnosisLeukocyte esterase Clean urine culture: b

28、acterial counts 105 /mlSuprapubic puncture, catheter collected urine 102/mlSignificant bacteriuria Microscopic bacteriuriaUrine Culture Test (very important)DiagnosisClean urine culture: bacterLocalization of UTI（No definite standard method） Ultrasonography Intravenous pyelography（IVP） Abdominal CT

29、/ MRILocalization of UTI（No definiTreatments for different types of UTIsTreatments for different typAcute uncomplicated cystitisPathogensStaphylococcus saprophyticus (5-15%)Enterobacteriaceae E. coli (86%)Klebsiella pneumoniaeProteus Enterococcus Acute uncomplicated cystitisPSingle-dose therapy is l

30、ess effectiveEspecially with -lactams3-day course recommendedTMP-SMX, fluoroquinolone, nitrofurantoinNOT appropriate for male patients and complicated UTIs7-day course: Diabetes , age 65 years, MalesIf untreated: may lead to acute uncomplicated pyelonephritis treatmentAcute uncomplicated cystitisTre

31、atment - Antibiotic TherapySingle-dose therapy is lessAcute uncomplicated pyelonephritisPathogensEnterobacteriaceaeE. coli Klebsiella pneumoniaeProteus Staphylococcus saprophyticus Acute uncomplicated pyelonephrMild or moderate symptoms:Outpatient treatment ( 714 days) Oral treatment: Fluoroquinolon

32、e, TMP/SMX, third generation cephalosporinSevere ill patient: Hospitalization requiredParenteral therapy (14 days) Broad-spectrum cephalosporins or FluoroquinolonesAcute uncomplicated pyelonephritisTreatment ( 714 days) Mild or moderate symptoms:AcutComplicated UTIsPathogensEnterobacteriaceaeE. Coli

33、 Klebsiella pneumoniaeProteusEnterococciPseudomonasStaphylococciComplicated UTIsPathogensEnMinimal or mild symptoms (10-14d).Oral therapy: fluoroquinolone (ciprofloxacin or ofloxacin)Severe ill patient, parenteral therapy (10-21d).Hospitalization required, Imipenem alone Penicillin or cephalosporin

34、plus aminoglycoside Third generation cephalosporin: Ceftriaxone or ceftazidimeComplicated UTIsTreatmentMinimal or mild symptoms (1Low urinary tract infection (acute cystitis) : 7 days course antibiotics Amoxicillin, cephalosporine, nitrofurantoinPyelonephritis: 2-4 weeks course antibiotics Cephalosporins, extended spectrum penicillins Parenteral treatment Follow-up urine culture tests, monthly Low-dose prophylaxis to recurrent infectionsAsymptimatic bacteriuria Antibiotics treatments are needed.UTI in Pregnant womenTre