urinary track infection etiology ,cystitis,acute chronic pyelonephritis

#urinary track infections ,acute, chronic pyelonephritis ,cystitis, etiology,

1. URINARY TRACK INFECTIONS

2. CONTENTS Introduction Historical aspects of inflammation Causes of inflammation Types of inflammation Acute & chronic inflammation Pathophysiology of acute inflammation Chemical mediators of inflammation Methods Conclusions References 2

3. introduction UTI is the infection in any part of the urinary system. More common in women. Infection of upper urinary tract – kidney infection ( pyelonephritis ). Infection of lower urinary tract – bladder infection ( cystitis ). 3

4. Acute pyelonephritis It is an acute suppurative inflammation caused by pyogenic bacteria. ETIOPATHOGENESIS It is the infection of lower urinary tract. The most common pathogenic organism in urinary tract infection (UTI) is Escherichia coli (in 90% of cases), followed by Enterobacter , Klebsiella , Pseudomonas and Proteus . The bacteria gain entry into the urinary tract, and then into the kidney by one of the two routes: Ascending infection Haematogenous infection 4 4

5. 1. Ascending infection: Most common route of infection. Pathogenic organisms are inhabitants of the colon and may cause faecal contamination of the urethral orifice, especially in females in reproductive age group. Females (shorter urethra) are liable to faecal contamination , hormonal influences facilitating bacterial adherence to the mucosa , absence of prostatic secretions which have antibacterial properties, and urethral trauma during sexual intercourse (honeymoon pyelitis ). Susceptibility is increased in patients with diabetes mellitus, pregnancy, urinary tract obstruction. 5

6. Bacteria multiply in the urinary bladder and produce asymptomatic bacteriuria found in many of these cases. After having caused urethritis and cystitis, the bacteria in susceptible cases ascend further up into the ureters against the flow of urine, extend into the renal pelvis and then the renal cortex. The role of vesico -ureteral reflux is not a significant factor in the pathogenesis of acute pyelonephritis as it is in chronic pyelonephritis. 6 Pathogenesis of reflux nephropathy

7. 1. Haematogenous infection: It is less often. Acute pyelonephritis may result from blood-borne spread of infection. This occurs more often in patients with obstructive lesions in the urinary tract , and in debilitated or immunosuppressed patients . CLINICAL FEATURES Acute onset with chills, fever, loin pain, lumbar tenderness, dysuria and frequency of micturition . Urine will show abundance of bacteria, pus cells and pus cell casts in the urinary sediment. Institution of specific antibiotics, after identification of bacteria by culture followed by sensitivity test, eradicates the infection in majority of patients. 7

8. Chronic pyelonephritis It is a chronic tubulointerstitial disease resulting from repeated attacks of inflammation and scarring. ETIOPATHOGENESIS Depending upon the etiology and pathogenesis, two types of chronic pyelonephritis are described- Reflux nephropathy Obstructive pyelonephritis 8 8

9. 1. Reflux nephropathy : Reflux of urine from the bladder into one or both the ureters during micturition is the major cause of chronic pyelonephritis. Reflux results in increase in pressure in the renal pelvis so that the urine is forced into renal tubules which is eventually followed by damage to the kidney and scar formation . Vesicoureteric reflux is more common in patients with urinary tract infection, whether symptomatic or asymptomatic, but reflux of sterile urine can also cause renal damage. 9

10. 2. Obstructive pyelonephritis: Obstruction to the outflow of urine at different levels predisposes the kidney to infection Recurrent episodes of such obstruction and infection result in renal damage and scarring. Rarely, recurrent attacks of acute pyelonephritis may cause renal damage and scarring. CLINICAL FEATURES Chronic pyelonephritis often has an insidious onset. The patients present with clinical picture of chronic renal failure or with symptoms of hypertension. Sometimes, the patients may present with features of acute recurrent pyelonephritis with fever, loin pain, lumbar tenderness, dysuria, pyouria , bacteriuria and frequency of micturition. Diagnosis is made by intravenous pyelography ( IVP ). Culture of the urine may give positive results. 10

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12. cystitis Inflammation of the urinary bladder is called cystitis. Primary cystitis is rare since the normal bladder epithelium is quite resistant to infection. Cystitis may occur by spread of infection from upper urinary tract as seen following renal tuberculosis, or may spread from the urethra such as in instrumentation . 12 12

13. Etiology The most common pathogenic organism in UTI is E. coli , followed in decreasing frequency by Enterobacter , Klebsiella , Pseudomonas and Proteus. Infection with Candida albicans may occur in the bladder in immunosuppressed patients. Parasitic infestations such as with Schistosoma haematobium is common in the Middle-East countries, particularly in Egypt. Chlamydia and Mycoplasma may occasionally cause cystitis. Radiation, direct exposure to chemical irritant, foreign bodies and local trauma may all initiate cystitis. It is more common in females than in males because of the shortness of urethra which is liable to faecal contamination and due to mechanical trauma during sexual intercourse. In males, prostatic obstruction is a frequent cause of cystitis. 13 13

14. CLINICAL FEATURES Frequency (repeated urination), Dysuria (painful or burning micturition) and Low abdominal pain. Systemic manifestations of bacteraemia such as fever, chills and malaise 14

15. TYPES OF CYSTITIS: 15 S. No. Acute cystitis Chronic cystitis 1. The bladder mucosa is red, swollen and haemorrhagic with suppurative exudate or ulcers on the bladder mucosa. Repeated attacks of acute cystitis lead to chronic cystitis. The mucosal epithelium is thickened, red and granular with formation of polypoid masses. Long-standing cases result in thickened bladder wall and shrunken cavity.