Urinary Tract Infection Presented to: Dr. Hasan Fahmawi Dr. Enas Abu Saleem By: Amer Al-Salamat.

Introduction Definition: Symptomatic presence of micro organisms within the urinary tract, associated with inflammation. i.e.: kidney, ureters, bladder, urethra,and prostate in males The most common UTI is uncomplicated acute cystitis.

Classification UTI divided into: 1-Upper , include: -Acute, Chronic, and interstitial pyleonephritis. 2- Lower , inlude: -cystitis, prostatitis, urethritis. Both upper and lower UTI are further divided into complicated and uncomplicated.

Epidemiology Common disorder, especially in females. 33% to 50% of all women experience UTI in their lifetime. In males, UTI is uncommon, except in the first year of life and in men over 60 years.

Pathogenesis 4 routes of bacterial entry to urinary tract: 1- Ascending infection. (M.C) 2-Blood brone spread. 3-lymphatogenic spread. 4-Direct extension from other organs.

Pathophysiology Infection most often caused by bacterial colonization of the vaginal area by pathogens from fecal flora leads to ascend via the urethra into the bladder. In women, the ascent of organisms is easier than in men; the urethra is shorter and the absence of bactericidal prostatic secretions may be relevant.

Common organisms: E.coli (most common): (70-80)% of cases. Other organisms- S.saprophyticus, Enterococcus fecialis, proteus, psedomanas, klabsiella. Multiplication of organisms depends on a number of factors, including the size of the inoculum and virulence of the bacteria.

Risk Factors Female gender : short urethra, vaginal colonization. Sex intercourse : honey moon cystitis. Use of diaphragms, spermicides. Pregnancy. Indwelling urinary catheter. Urinary tract stones. Urinary tract stasis. DM, immunosupression, spinal cord injury.

Male risk factors: Personal history of recurrent UTI. Neurogenic bladder. Vesicoureteral reflux. Male risk factors: Uncircumcised males, anal intercourse, and vaginal intercourse with female colonized with uropathogen.

Clinical Features Most typical symptoms of cystitis and urethritis (lower) include: Frequency of micturition. Dysuria. Suprapubic pain and tenderness. Hematuria (mainly visible). Urgency and Strangury. Smelly urine (unpleasant).

Systemic symptoms are usually slight or absent. Infection in the lower urinary tract can spread to cause acute pyelonephritis, thus systemic symptoms appear, such as: -lion pain, fever, tenderness, chills, night sweats, rigors, vomiting, and hypotension. Prostatitis is suggested by: - perineal or suprapubic pain, pain on ejaculation and prostatic tenderness on rectal examination

The differential diagnosis of acute pyelonephritis includes pyelonephrosis, acute appendicitis, diverticulitis, cholecystitis, salpingitis, ruptured ovarian cyst or ectopic pregnancy

Investigation The diagnosis can be made from the combination of typical clinical features and abnormalities on urinalysis. 1-Dipstick urinalysis: -Positive urine leukocyte esterase test (reflect pyuria). -positive nitrate test for presence of bacteria (gram negative) (sensitive and specific for enterobacteriaccea). -combining the above two tests yields a sensitivity of 85% and specificity of 75%.

Most urinary pathogens can reduce nitrate to nitrite, and neutrophils and nitrites can usually be detected in symptomatic infections by urine dipstick tests for leucocyte esterase and nitrite, respectively.

2-Urinalysis (clean-catch mid stream specimen). -adequacy of collection. Presence of epithelial cells indicate valvar or urethral contamination.(perform striaght cath of the bladder) Criteria: Bacteruria>1 organism per oil immersion field Bacteruria without WBC reflect contamination and not reliable Indicator of infection.

Pyuria is the most valuble finding for diagnosis >= 10 leukocyte/micro L is abnormal Other findings: hematuria, mild proteinuria. 3-Urine gram stain >10^5 organism\mL : significant bacteruria. 90% sensitive and 88% specific.

4-Urine culture. High specificity Symptomatic female Symptomatic male Asymptomatic >10^2 coliform organism\ml plus pyuria(>10 leukocyte). >= 10^5 any pathogenic organism\ml. Any growth by suprapubic aspiration. >10^3 pathogenic organism\ml. <10^5 pathogenic organism\ml on two occasions.

5- Blood culture: only indicated if patient ill and urosepsis is suspected. 6-cytoscopy, IVP(intravenous pylogram), excretory urography not recommended only if obstruction suspected.

Management Antibiotics : recommended in all cases of proven UTI (symptomatic). Treatment may be started while awaiting the result of urine culture. Asymptomatic: no treatment required except in special situations. Treatment duration: Single dose therapy. 3 day course(the norm, less likely to induce significant alterations in bowel flora compaired with 7 day course). 7 day course. 10-14 day course.

Trimethoprim or nitrofurantoin is the usual first choice of drug for initial treatment. Between 10% and 40% of organisms causing UTI are resistant to trimethoprim. Quinolone antibiotics such as ciprofloxacin and norfloxacin, and cefalexin are also generally effective.(altrenative) Co-amoxiclav and amoxicillin are no longer recommended as blind therapy, as up to 30% of organisms are resistant.

Penicillins and cephalosporins are safe to use in pregnancy but trimethoprim, sulphonamides, quinolones and tetracyclines should be avoided. Also, drugs of choice for UTI with Renal faliure. In more severe infection, antibiotics should be continued for 7–14 days. Seriously ill patients may require intravenous therapy with gentamicin for a few days later switching to an oral agent.

Recurrent infection: If relapse occurs within 2 weeks of cessation of treatment , continue treatment for 2 more weeks and obtain urine culture. Urinary analgesic: Phenazopyridine (1 to 3 days for dysuria). Non specific therapy: More water intake.(dysuria worse) Maintaining acidity of urine by fluids like canberry juice.

Conclusion Urinary tract infections are the second most common bacterial infection. Women are the most infected subjects in population. Development of resistance to antibiotics by the bacteria result in problems during the treatment and lead to relapse and recurrence.

Reference Kumar and Clark's Clinical Medicine (9th edition). Davidson’s principle and practice of medicine (23rd edition). Step-up to medicine(4th edition).

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