tractinfection（尿路感染全英文）图文课件

Urinary Tract Infection Wu Yitai Department of Nephrology Tongji Hospital, Tongji University,Content,Definitions Epidemiology Etiology Pathogenesis Pathology Clinical presentation Diagnosis Treatments Complication Prevention,Definition of UTI,UTI is defined as the presence of micro-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, and frequency, but without bacteriuria.,Anatomic Lower UTI: urethritis cystitis (mucosal infection) Upper UTI: pyelonephritis prostatitis intrarenal and perinephric abscesses (tissue invasion),Classification of UTIs（1）,Classification of UTIs（2）,Clinical Uncomplicated UTI: Lack structural or functional abnormalities of the urinary tract Normal flow of urine NO interference with the normal defenses Complicated UTI: Predisposing lesion of the urinary tract, structural or functional abnormalities, e.g. congenital abnormality of the urinary tract, stone, obstruction, catheter. Interference with the normal defenses, e.g. immunosuppression, renal disease, or diabetes.,Classification of UTIs（3）,Epidemiology Catheter-associated（nosocomial）infections: Symptomatic Asymptomtic Non Catheter-associated（community-acquired）infections: Symptomatic Asymptomtic,Epidemiology,Almost 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.,Etiology（1）,Community-Acquired UTI gram-negative bacilli is the most common agent,E. coli,Enterobacter,Enterococcus,Proteus,Staphylococcus,Klebsiella,E. coli,Etiology（2）,Causative organisms: Escherichia coli Klebsiella, proteus and pseudomonas 1- Bacteria S. aureus, Staphylococcus epidermidis and S. saprophyticus Enterococci (Streptococcus faecalis粪链球菌) Mycobacterium tuberculosis Chlamydia trachomatis, Neisseria gonorrhoeae 2- Virus Herpes simplex virus , HIV 3- Fungus Candida, Histoplasma capsulatum 4- Protozoon Trichomonas vaginalis, Schistoma haematobium,CASE 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 faecalis,CASE 3 18 year-old woman Dysuria and frequency; Pyuria; Gram positive cocci; Staphylococcus.,CASE 4 42 year-old diabetic woman with a catheter. Gram positive yeasts. Candida grew.,Route of Infection,Ascending route (the most common),Colonization of urethra,Pathogenesis,Pathogenesis（1）,The urinary tract 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 （2）,Host defense mechanisms: 1. Urine: low pH, high osmolality, high urea & organic acid concentration inhibit and kill microorganisms 2. Regular urine flow: dilute and expel pathogens 3. Bladder epithelial cells: coated with mucus (glycosaminoglycan) prevent bacteria from adhering to bladder wall,Conditions affecting pathogenesis,Gender and sexual activity. Pregnancy. Obstruction. （tumor, stricture, stone, BPH） Neurogenic bladder dysfunction. Vesicoureteral reflux Bacterial virulence factors Genetic factors （details in the following）,Conditions affecting pathogenesis（1）,Gender and sexual activity The female 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 obstruction due to prostatic hypertrophy.,Conditions affecting pathogenesis（2）,Pregnancy UTIs are detected in 2 to 8% of pregnant women. Pregnant women with asymptomatic bacteriuria. Bladder catheterization during or after delivery causes additional infections.,Conditions affecting pathogenesis（3）,Obstruction Tumor Stricture Stone Benign prostatic hypertrophy (BPH) These conditions result in hydronephrosis and increase frequency of UTI.,Conditions affecting pathogenesis（4）,Neurogenic Bladder Dysfunction Interference with 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 pathogenesis（5）,Vesicoureteral Reflux Vesicoureteral 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 pathogenesis（6）,Bacterial Virulence factors Specific 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 aerobactin.,Conditions affecting pathogenesis（7）,Genetic factors Host genetic factors influence susceptibility to UTI. The number and type of receptors on uroepithelial cells are in part genetically determined.,Conditions affecting pathogenesis,Gender and sexual activity. Pregnancy. Obstruction. （tumor, stricture, stone, BPH） Neurogenic Bladder Dysfunction. Vesicoureteral Reflux Bacterial Virulence factors Genetic factors,Pathology,Cystitis,Mucosal hyperemia Edema Leukocyte infiltration Easy bleeding Granular surface Superficial ulcer Purulent exudate,Pathology,Acute Pyelonephritis,Acute inflammation Hyperemia and edema Volume increase Red colour Yellowish abscess Purulent exudate,Pathology,Chronic Pyelonephritis,Chronic inflammation Pelvis deformed Cortex scars Volume shrink Asymmetric Parenchyma atrophy,Pathology,Interstitial edema Neutrophil infiltration White blood cell cast,In microscopy,Clinical Presentation,Clinical presentation（1）,Cystitis Burning pain Frequency, urgency Suprapubic pain Dysuria,Clinical presentation（2）,Urethritis Burning pain Frequency, urgency Dysuria Infected with sexually transmitted pathogens,Clinical presentation（3）,Acute Pyelonephritis All cystitis symptoms（+）or（-） Fever, shaking chills Nausea, vomiting, diarrhea Tachycardia, hypotention Muscle tenderness Costovertebral angle（CVA） pain Gram-negative sepsis , Leukocytosis Leukocyte casts in the urine,Clinical presentation（4）,Catheter-Associated UTIs Bacteriuria develops in at least 10 to 15% of hospitalized patients with indwelling urethral catheters. The risk of infection is 3 to 5% per day of catheterization. Many infecting bacteria display markedly great antimicrobial resistance.,How is it diagnosed?,Diagnosis,Patient history Complete physical examination Urine culture Urine analysis Other examinations,Microscopic Examination,Pyuria WBC 5 / HP,Bacterial colony counts 105 / ml,Diagnosis,Diagnosis Dipstick Methods,Leukocyte esterase + Nitrite +,Urine routine: pH, sg, protein, glucose, blood, ket, etc.,Clean urine culture: bacterial counts 105 /ml Suprapubic puncture, catheter collected urine 102/ml Significant bacteriuria Microscopic bacteriuria,Urine Culture Test (very important),Diagnosis,Localization of UTI,（No definite standard method）,Ultrasonography Intravenous pyelography（IVP） Abdominal CT / MRI,Treatments for different types of UTIs,Acute uncomplicated cystitis Pathogens,Staphylococcus saprophyticus (5-15%) Enterobacteriaceae E. coli (86%) Klebsiella pneumoniae Proteus Enterococcus,Single-dose therapy is less effective Especially with -lactams 3-day course recommended TMP-SMX, fluoroquinolone, nitrofurantoin NOT appropriate for male patients and complicated UTIs 7-day course: Diabetes , age 65 years, Males If untreated: may lead to acute uncomplicated pyelonephritis treatment,Acute uncomplicated cystitis Treatment - Antibiotic Therapy,Acute uncomplicated pyelonephritis Pathogens,Enterobacteriaceae E. coli Klebsiella pneumoniae Proteus Staphylococcus saprophyticus,Mild or moderate symptoms: Outpatient treatment ( 714 days) Oral treatment: Fluoroquinolone, TMP/SMX, third generation cephalosporin Severe ill patient: Hospitalization required Parenteral therapy (14 days) Broad-spectrum cephalosporins or Fluoroquinolones,Acute uncomplicated pyelonephritis Treatment ( 714 days),Complicated UTIs Pathogens,Enterobacteriaceae E. Coli Klebsiella pneumoniae Proteus Enterococci Pseudomonas Staphylococci,Minimal 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 plus aminoglycoside Third generation cephalosporin: Ceftriaxone or ceftazidime,Complicated UTIs Treatment,Low urinary tract infection (acute cystitis) : 7 days course antibiotics Amoxicillin, cephalosporine, nitrofurantoin Pyelonephritis: 2-4 weeks course antibiotics Cephalosporins, extended spectrum penicillins Parenteral treatment Follow-up urine culture tests, monthly Low-dose prophylaxis to recurrent infections Asymptimatic bacteriuria Antibiotics treatments are needed.,UTI in Pregnant women Treatment,UTI in ca