MDS Urinary Tract Infection Dr Johny

URINARY TRACT INFECTIONS Urinary Tract Infections [cont] The student should know as background knowledge: - Normal anatomy of the Urinary tract: Kidneys Ureters Bladder Urethra Prostate • Pelvi-ureteric Junction • Vesico-ureteric Junction • Sphincter mechanisms Pelvic diaphragm (females) Prostate, bulbar urethra (males) Urinary Tract Infections [cont] • Innervation of the urinary tract: – Sympathetic and para sympathetic systems – Spinal segments involved: Ureters (L1-L2) Bladder, urethra (Tll-L3) Pelvic diaphragm (S2-S4) • Embryology of kidney and urinary tract: – – – – – – Horse shoe kidney Absence/hypoplastic kidneys Cystic kidneys Posterior urethral valve, urethral atresia Duplex collecting systems Vesico ureteric reflux Case History: Ayesha is a 5 year old Kuwaiti girl who was brought to the hospital with fever upto 30 oC of 24 hours duration. She initially started having abdominal pain, became clearly ill with tiredness and diffuse abdominal and bilateral flank tenderness. She was sweating excessively and vomited twice. Her BP was 70/40. Physical examination was otherwise unremarkable. Ayesha is the 4th child in the family. All the other children are healthy with no medical problems. Past Medical History: Ayesha had episodes of febrile illness 4 to 5 times in the past and was taken to the polyclinics. She received some antibiotics with relief. But was never investigated. On further questioning, the mother said that Ayesha, unlike her other children continues to wet her bed at night even now. She is also slow to grow in height compared to other children. • Urine analysis showed - protein + - blood + Microscopy - WBC > 200 per HPF with leucocyte casts - RBC 5-10 per HPF - Blood - WBC count - 23.0 x 109/L with 85% neutrophils - Serum creatinine - 100 µmol/L (60-120) - Blood and urine cultures were taken The child was admitted to hospital and started on intravenous fluids and antibiotics. She started to feel better with improvement in the height of fever. - 48 hours later her urine culture showed a pure growth of E. Coli - Blood culture also grew the same organism. What are the major symptoms (History) at presentation: • High fever – 24 hours duration (Acute onset) • Abdominal and bilateral flank pain (Renal type) • Excessive sweating and vomiting (Toxic) What are the major physical findings (signs) at presentation: • • • • • High fever Excessive sweating Toxic fever Vomiting Tiredness Hypovolemia Low BP (70/40) What are the major abnormal laboratory findings (Investigations): • Urine: protein + blood + leucocyte casts (Nephronal leukocyturia) Culture: pure growth of E. Coli • Blood: WBC count: 23.0 x 109/L Neutrophils: 80% (neutrophil leucocytosis) Culture: grew E. Coli (Septicemia) • S. creatinine: 100 µmol/L (?? Normal) What is the past medical history: • Previous episodes of fever responding to antibiotic treatment (Infections) Wetting the bed at night (Eneuresis) Delayed growth (? Renal failure) • • What are the important features: • • • • • Acute febrile illness with toxic manifestations Abdominal and bilateral flank pain and tenderness Leucocyturia with casts Positive urine culture Positive blood culture What is the Diagnosis: • Acute urinary tract infection (Pyelonephritis) • Complicating bacteremia (Septicemia) URINARY TRACT INFECTION MICROBIAL INVASION OF GENITOURINARY TRACT Bacterial colony count in urine : > 100,000/ml. > 109/L UPPER URINARY TRACT: Kidney and Ureters LOWER URINARY TRACT: Bladder, prostate, urethra. PYELONEPHRITIS Bacterial invasion of renal interstitium (Upper U Tract) (A) ACUTE: SYMPTOMATIC Fever, Chills, flank pain POSITIVE URINE CULTURE URINARY TRACT INFECTION (contd.) (B) CHRONIC: - Presumptively of Bacterial infection - Acute symptoms are usually absent - Urine culture is often negative - Diagnosis: Radiological - DIAGNOSTIC Histological findings - NON-SPECIFIC CYSTITIS, URETHRITIS, PROSTATITIS Bacterial invasion of Lower Urinary tract SYMPTOMATIC: Dysuria, frequency, urgency URINE CULTURE: Positive URINARY TRACT INFECTION (contd.) URETHRAL SYNDROME (1/3 of women with symptoms) SYMPTOMATIC: URINE CULTURE ROUTINE NEGATIVE for CULTURE 3/4 - Have pyuria - Low Bacterial counts - STD ASSYMPTOMATIC BACTERIURIA - POSITIVE URINE CULTURE - NO ASSOCIATED SYMPTOMS URINARY TRACT INFECTION (contd.) RECURRENT INFECTIONS (a) RELAPSING: - Repeat infection with the SAME organism despite treatment and cure - Occurs after 1-2 weeks of stopping antibiotic therapy - More commonly after Bacterial Pyelonephritis OR Prostatitis (b) RE-INFECTION: - Repeat infection with a NEW organism - More common in cystitis and urethritis INCIDENCE FEMALES: - 15% of all women at some time in life - INFANTS - < 1 percent - CHILD HOOD - 1 - 3 percent - CHILD BEARING AGE - 2 to 5 % - PREGNANCY - 2 - 10 % - OLDER WOMEN - 5 to 15% MALES: - INFANTS - 1 percent - UPTO 45 years - < 1 percent - AFTER 45 years - 5% - Generally infections are rare before 45 years when present in young adults - prostatis is likely CLINICAL PRESENTATION - LOWER URINARY SYMPTOMS: (L.U.T) DYSURIA FREQUENCY URGENCY - UPPER URINARY: (U.U.T) LOIN PAIN FEVER WITH CHILLS - ASSYMPTOMATIC - WITH L.U.T. SYMPTOMS AND BACTERIURIA - 1/2 HAVE PYELONEPHRITIS - 1/2 HAVE CYSTITIS - WITH ACUTE LOWER URINARY SYMPTOMS - 60-70% HAVE BACTERIURIA - MAJORITY OF REST ALSO HAVE UNDERLYING INFECTION - SEXUALLY TRANSMITTED - LOW COLONY COUNT - BACTERIAL DIAGNOSIS OF URINARY TRACT INFECTION - EXAMINATION OF URINE: - Leukocytes, casts - Bacteria …………… - Epithelial cells 1 or more/HPF (75%) unspun 1 or more per HPF (90%) sample - URINE CULTURE - MID STREAM URINE (MSU) - CATHETER SAMPLE - SUPRAPUBIC ASPIRATION - BIOCHEMICAL TESTS - UTILIZATION OF GLUOSE - REDUCTION OF NITRATE TO NITRITE Bacterial properties DIAGNOSIS OF URINARY TRACT INFECTION(contd) DIPSTICK TECHNIQUE - GLUCOSE STRIP TEST - 90-95% - NITRITE STRIP TEST - 85% - FALSE POSITIVE - 5% Positive Positive LOCALIZATION OF INFECTION: - ANTIBODY COATED BACTERIA IN URINE RADIOGRAPHY AND OTHER UROLOGICAL PROCEDURES: - IVP - CYSTOSCOPY LOCALIZATION OF INFECTION - WHITE CELL CASTS - CONCENTRATING ABILITY DEFECT - RAISED SERUM ANTIBODIES - URETERAL CATHETER URINE SAMPLE - BLADDER WASHOUT TECHNIQUE - ANTI-BODY COATED BACTERIA false negative - 15 to 20% false positive - Prostatitis - Hgic cystitis - Yeast, psuedomonas cause autofluorescence - RAISED - C-REACTIVE PROTEIN (C.R.P.) - non specific PREDISPOSING FACTORS TO UTI 1: SEX: FEMALES : Short urethra, proximity to anus MALES : Prostatis, prostatic obstruction 2: PREGNANCY: Urine is more nutrient Stasis, obstruction, ureteral dilatation 3: OBSTRUCTIVE UROPATHY: Infection accelarates renal damage stasis predisposes to infection 4: NEUROGENIC BLADDER: Residual bladder urine Frequent catheterization PREDISPOSING FACTORS TO UTI (contd) 5: VESCICO URETERIC REFLUX: 6: RENAL DISEASES: Gout, nephrocalcinosis Sickle cell disease Hypokalemia, hypercalcemia 7: DIABETES: 8: IMMUNODEPRESSION: Post renal transplant 9: INSTRUMENTATION OF URINARY TRACT Catheter, cystoscopy etc: CATHETER ASSOCIATED INFECTIONS - SINGLE (STAB) CATHETERIZATION: < 2% - INDWELLING CATHETER : 5% per DAY - ORGANISMS DIFFER: Proteus, Pseudomonas, Klebsiella, Serratia ROUTE OF INFECTION: - INTRA LUMINAL - PERI URETHRAL SIGNIFICANCE - MOST ARE ASSYMPTOMATIC & BENIGN - 1 to 2% DEVELOP BACTEREMIA IS THE COMMONEST SOURCE OF BACTEREMIA IN HOSPITAL PATIENTS TREATMENT OF U.T.I. - OBTAIN Quantitative Bacterial Count and Sensitivity - IDENTIFY Predisposing factors, if any - FOLLOW UP CULTURES are needed after treatment period - CLASSIFY Infections - UPPER URINARY - Cysto urethritis - Prostatitis - Re-current - Relapse - Re infection - REMEMBER Clinical cure does not always mean bacteriological cure - SHORT TERM COURSE FOR CYSTO URETHRITIS (L.U.T) - LONGER PERIOD FOR TISSUE INVASION: Eg. Pyelonephritis Prostatitis TREATMENT (contd) - CYSTO URETHRITIS (L.U.T) - Single day therapy - 3gm ampicillin - 500mg Kanamycin I.M. - 4 to 6 tablets of CO-TRIMOXAZOLE - SHORT COURSE OF 7 DAYS - In children - In pregnant women - In men - Symptoms > 10 days - ACUTE PYELONEPHRITIS - 10 to 14 days course - IN RELAPSE 2 to 6 weeks course TREATMENT (contd) - PROSTATITIS - 3 Weeks Course - ANTIBIOTIC CHOICE - COMPLICATING SEPTICEMIA: Hospitalization, - cephalosporins, - Aminoglycosides - PROPHYLAXIS: > 2 Infections in six months. TREATMENT OF ASSYMPTOMATIC BACTERIURIA - SHOULD HAVE COLONY COUNTS > 100,000/c.m.m PREFERABLY ON MORE THAN 2 OCCASSIONS - FIRST REMOVE CUASES SUCH AS CATHETERS, STONES OR OBSTRUCTION - IN MEN AND NON-PREGNANT WOMEN IN THE ABSENCE OF UNDERLYING DISEASES NO TREATMENT IS WARRANTED - TREATMENT IS WARRANTED IN - PREGNANT WOMEN - YOUNG GIRLS - WHEN INSTRUMENTATION OF G.U.T IS PLANNED CHRONIC PYELONEPHRITIS Chronic Interstitial Nephritis thought to result from BACTERIAL INFECTION - ACUTE SYMPTOMS OF URINARY INFECTION ARE USUALLY ABSENT - PRESENT OR PAST HISTORY OF BACTERIURIA IS AVAILABLE IN LESS THAN 25% OF PATIENTS - PREDISPOSING FACTORS: – Vescico Uretcric reflus – Neurogenic bladder – Obstructive uropathy • ADULTS WITH UNCOMPLICATED BACTERIURIA RARELY, IF FEVER, DEVELOP CHRONIC PYNEPHRITIS CHRONIC PYELONEPHRITIS RADIOLOGICAL: IRREGULAR RENAL PELVIS, CALICTASIS SCARRING OF ADJACENT RENAL CORTEX CONTRACTED, BUT IRREGULAR BIOCHEMICAL: IMPAIRED RENAL FUNCTIONS: - Concentrating ability - Decreased Creatinine clearance PATHOLOGICAL: CHRONIC INTERSTITIAL NEPHRITIS URINE: PYURIA, PUS CELL CASTS CHRONIC PYELONEPHRITIS (contd) BACTERIURIA: - IN MANY PATIENTS BACTERIURIA IS ABSENT - ADULTS WITH UNCOMPLICATED BACTERIURAIA RARELY, IF EVER, DEVELOP CHRONIC PYELO. PREDISPOSING FACTORS: - VESICO URETERIC REFULX - OBSTRUCTIVE UROPATHY - NEUROGENIC BLADDER CLINICAL FEATURES: - POLYURIA, NOCTURIA - EARLY HYPERTENSION, RENAL FAILURE. CHRONIC INTERSTITIAL NEPHRITIS DIAGNOSIS IS LARGERLY BASED ON HISTOLOGY - Disproportionately greater involvement of tublointerstitium than glomeruli LABORATORY: - Mild to moderate degree of proteinuria only - Loss of concentrating ability - Fall in creatinine clearance - Bilaterally contracted kidneys CHRONIC INTERSTITIAL NEPHRITIS (contd.) CAUSES: - BACTERIAL PYELONEPHRITIS - TOXINS - Analgesic nephropahty - drugs - Gouty nephropathy, hypokalemia - hypercalcemia. - VASCULAR - Sickle cell nephropathy - Arteriolar nephrosclerosis - IMMUNOLOGICAL - Transplant rejection - sjogrens - OTHERS: - Heriditary nephritis - Radiation nephritis - Multiple myeloma - Balkan nephropathy Student Outcome: • Understand the clinical features and distinction between upper and lower urinary tract infections (UTI) • Understand the definition (terminology) of terms used to describe UTI • Describe the diagnosis of urinary tract infections - Organisms commonly associated with UTI - Mechanisms of microbial uropathogenecity • Describe the predisposing and underlying factors associated with UTI • Select the appropriate imaging techniques for the urinary tract when structural abnormalities are suspected • Understand the principles of treatment of upper and lower urinary tract infections • Understand the diagnosis, etiology, pathology and management of chronic pyelonephritis