Urinary tract infections UTIs DEFINITIONS UTI is an

Urinary tract infections (UTIs)

DEFINITIONS UTI is an inflammatory response of the urothelium to bacterial invasion that is usually associated with bacteriuria and pyuria, Epidemiology 1 usually relate to age and sex 2 it more common in male infant less 1 year (pre circumcision)after that female have higher incidence *The morbidity & mort. great at <1 y. & >65 y.

Bacteriuria is the presence of bacteria in the urine, which is normally free of bacteria & can be symptomatic or asymptomatic Pyuria, the presence of white blood cells (WBCs) in the urine, is generally indicative of infection and an inflammatory response of the urothelium to the bacterium

Bacteriuria without pyuria is generally indicative of bacterial colonization without infection of the urinary tract. Pyuria without bacteriuria warrants evaluation for tuberculosis, stones, or cancer UTIs are a result of interactions between the uropathogen and the host & determined in part by • the virulence factors of the bacteria, • the inoculum size, and • the inadequacy of host defense mechanisms

pathogenesis Routes of Infection 1 -Ascending Route 2 -Hematogenous Route Like TB, staph. Aureus 3 - lymphatic 4 - direct extension Host Defence : 1 compete bladder emptying 2urinary inhibiter of bacterial adhesion 3 lining urothelium physical barrier 4prostatic zinc secration 5normal periurethral flora of lactobacilli

Bacterial pathogenic factors 1)Adhesion lead to infection 2)Bact. with more adherent property lead to more pathogenic inf. 3)Bacterial fimbiae it 2 types • type 1 causing cystitis • Type p pili causing pyelonephratis Important note more than 80% of UTIs used by E. coli other less likly like klebsiella, proteus, pseudomonas and staph

Alterations in Host Defense Mechanisms -Obstruction -Vesicoureteral Reflux -Underlying Disease include diabetes mellitus (renal papillary necrosis), sickle cell disorders, analgesic abuse, sulfonamide nephropathy, gout, heavy-metal poisoning, and aging -Pregnancy -Spinal Cord Injury with High-Pressure Bladders

GUE

Urine Collection 1 - voided specimens a midstream specimen (representative of the bladder) 2 - Catheterized Specimens 3 -Suprapubic Aspiration Macroscopic examination 1 -colour &appearance: drugs &food *red urine does not always signify hematuria. *cloudy urine, -amorphous phosphate (the most common cause) -or pyuria 2 -specific gravity. 1003 -1030, dehydration increase it

3 -chemical tests Ph Normaly 4. 5 to 8 ~ph –uric acid stone in ph less than 6. 5 (uric acid soluble in alkaline media) -RTA failure of kidney to acidify urine below ph of 6. 0 -UTI by urea splitting organism (proteus) ph more than 7. 0 ~Protein proteinuria more than 150 mg/24 hr Glucose glucose in urine if bl. Glucose more than 180 (D. M) or low renal threshold of glucose excretion.

Microscopic examination Interpretation: A-bacteria. B-leukocytes just as the presence of bact. is not an absolute indication of infection neither is the finding of pyuria. Pyuria : is the presence of more than 3 leukocytes/hpf ~symptom of uti+pyuria+bacteruria=diagnoses of infection& initiating emperic therapy

One can verify the diagnoses by bacterial culture -estimate the number of bact. , -identify the exact organism, & -predict the drug will be effective in treating infection. *renal TB. Should be considered in any pt. with sterile pyuria *urolithiases & malignancy can also cause sterile pyuria.

C- Erythrocytes. the presence of more than 3 RBCs/ml in urine (hematuria) is abn. &require further investigation. dysmorphic RBCs indicate active glomerular disease result from extreme changes in osmolality affecting RBC during their passage through renal tubules D-epithelial cells Sequamous cells-indicate contamination Transitional cells-of no significance unless abnormal histologically.

E- Casts formed in the distal tubules & collecting ducts, commonly signify intrinsic renal disease -leukocyte casts suggest p. n. -erythrocyte casts =underlying vasculitis or glomerulitis. -epithelial casts of little significance be differentiated from leukocyte casts. -hyaline casts of no significance. -granular casts disintegrated WBC and epithelial cells =intrinsic renal disease -Crystals of varying importance (cystine, leucine, tyrosine )

IMAGING TECHNIQUES Radiologic studies are unnecessary for evaluation of most women with genitourinary infections. Indication including 1 -high-risk patients, febrial UTI and most men, 2 -acute infectious processes that require further intervention or may find the cause of complicated infections with possible UT obstruction

3 -bacteriuria fails to resolve after appropriate antimicrobial therapy or who have rapid recurrence of infection, abnormalities that cause bacterial persistence should be sought -prophylactic to keep the urine sterile -Suppressive, to prevent already present bact. infecting ut. .

PRINCIPLES OF ANTIMICROBIAL THERAPY Factors important in aiding selection of empirical therapy include whether -the infection is complicated or uncomplicated; -the spectrum of activity of the drug against the probable pathogen; -a history of hypersensitivity; -potential side effects, including renal and hepatic toxicity; and -cost

Trimethoprim/Sulfamethoxazole -mostly used in non complicated UTI -Antagonism of bacterial folate metabolism C. I, folic acid def, G 6 PD def, pregnancy Nitrofurantoin -It have high urinary level but does not obtain therapeutic levels in most body tissues Cephalosporins -Inhibition of bacterial cell wall synthesis -They are also useful during pregnancy Aminopenicillins -Inhibition of bacterial cell wall synthesis -the emergence of resistance in 40% to 60%

Aminoglycosides -Inhibition of ribosomal protein synthesis -Their nephrotoxicity and ototoxicity -When combined with TMP-SMX or ampicillin, aminoglycosides are the first drugs of choice for febrile UTIs Fluoroquinolones -Inhibition of bacterial DNA gyrase -have a broad spectrum of activity that makes them ideal for the empirical treatment of UTIs - C. I-children, pregnant & lactating F.

BLADDER INFECTIONS Usually affected female UTIs in most men should be considered complicated until proven otherwise Clinical Presentation dysuria, frequency or urgency, supra pubic pain Hematuria or foul-smelling urine may develop E. Coli is the causative organism in 75% to 90% S. saprophyticus a commensal organism of the skin, is the second most common cause

Laboratory Diagnosis 1Urinalysis : WBC, pus, RBCs 2urine culture : confirm dx, and pathogen 3Radiology : only in complicated Treatment uncomplicated (normally functional and anatomacal) short corse 3 -5 days of singal antibiotic Complicated used multiple antibiotic for longer time Bact. persistance : persistance same oragnism and same species despite of treat. due to ston, fistula Reinfection reinfaction by anew ather oragansim which is the most common cause of recurrent UTI.

Acute Pyelonephritis 1inflammation of the kidney and renal pelvis, the diagnosis is clinical. C. F: § common in female §High grad fever with riger §Renal angle tenderness §Lower tract symp. like dysuria, frequency §Sepsis §Children have diffuse abdom. Pain, failure to thrive or asymptomatic

Investigation • Urinalysis : WBC, RBC • Leukocytosis. increase ESR • Urine culture : 80% E. coli • Blood culture : +ve in 2/3 of cases • Radiological images A- u/s B-CT with contrast C-radioistop scan

Management 10 -30%of pt need admission 1 - Empiric Rx Ampiciline IV +Aminoglycoside or 3 rd genereation. cephalosprine or fluroquinolones 2 -shift to antibiotics based on culture If -ve bacteraemia then continue paranteral Ab for 35 day and change to total 10 -14 days If +ve bacteraemia continue paranteral Ab for 7 -10 day then oral to 10 -14 days • less toxic could treated as out patient with oral flouroquinolone or TMP-SMX for 10 -14 days • If fever for>3 day on Rx then suspect renal abscess

Some pat need follow up by Urine culture Radiological exam like Voiding cysto urethrography Differential Diagnosis Acute appendicitis, diverticulitis, and pancreatitis can cause a similar degree of pain, but the location of the pain often is different