LOWER URINARY TRACT INFECTIONS Assist Prof Microbiology Dr. Syed Yousaf Kazmi

LEARNING OBJECTIVES 1. Discuss epidemiology of urinary tract infections 2. Define lower urinary tract infections and its various causes 3. Explain the patho- physiological changes 4. Describe the symptoms, signs and various medical conditions associated 5. Discuss the investigations and principles of management

EPIDEMIOLOGY OF UTIs  Half to 1/3 human suffer a UTI during life  In USA 1 % of outpatient visit is due to UTI  10 million doctor visits/ year  Half of women will develop UTI in lifetime  Most of those will be during pregnancy  Almost 95% UTIs –bacteria multiply at the opening of the urethra and travel up to the bladder  Commonest UTIs are Cystitis

EPIDEMIOLOGY OF UTIs  Between the ages of 16 and 35 years  10% of women getting an infection yearly  Urinary tract infections may affect 10% of people during childhood  Most common in uncircumcised males less than three months of age  UTI in men is rare before 5 th decade  E. coli is most common etiological agent

DEFINITION OF LOWER UTI “Infection of urethra/ urinary bladder is called Lower UTI”  Complicated UTI-when infection associated with functional/ structural abnormality  Uncomplicated UTI- infection with normal GUS  Primary UTI  Recurrent UTI

DEFENSE SYSTEMS AGAINST UTIs  Flushing action of urine  Acidic urine inhibits pathogens  The prostate gland in men secretes Zinc-fights bacteria  Surface IgA  Antibacterial substances from uro-epithelium  Low vaginal pH-inhibits UTI causing bacteria

RISK FACTORS UNCOMPLICATED UTIs  Female anatomy  Pregnancy  Sexual intercourse  Less fluid intake  Family history COMPLICATED UTIs  Urinary flow obstruction e.g. BPH, strictures, urethral valves, Ca bladder, stones, uncircumcised,  Fistulas e.g. recto-vesical, recto-vaginal etc.  Urinary catheterization  Renal/ vesicle stones  Systemic diseases e.g. DM, Spinal cord injury

MICROBIOLOGICAL CAUSES IN UNCOMPLICATED CYSTITIS  Escherichia coli (86 %)  Staphylococcus saprophyticus  Klebsiella species  Proteus species  Enterobacter species  Citrobacter species  Enterococcus species  Others (viruses, fungi, parasites)

PATHOPHYSIOLOGY  Bacteria are introduced in urethra  Bacterial factors e.g. pili of E. coli, IgA protease etc. overcome defense mech  Multiply in urethra  Move into Urinary bladder by attaching uro-epithelium  In bladder, multiply more readily  Urine is good culture medium  Usually surface epithelium involved  Deeper layers in chronic cases  Acute inflammation-Neutrophils, RBCs, Protein leaks into bladder-in urine

SIGNS & SYMPTOMS-ADULTS  Dysuria  Urinary urgency and frequency(a frequent, urge to urinate, but only passing small amounts or no urine)  Sensation of bladder fullness  Lower abdominal discomfort  Flank pain and costo-vertebral angle tenderness (referred pain)  Cloudy, dark or strong smelling urine  Haematuria  Fever, body aches, lethargy

SIGNS & SYMPTOMS- CHILDREN  Off feed  Nausea and vomiting  Loose motions  Frequent urination (problem in babies with nappy)

DIFFERENTIAL DIAGNOSIS  Cervicitis (inflammation of the cervix)  Vaginitis  Interstitial cystitis (chronic pain in the bladder)  Prostatitis  Renal tuberculosis  Genitourinary malignancy  Vesicular/ urethral calculi  Any peri-urethral process

DIAGNOSIS URINANALYSIS(Dipstic k)  Cloudy, turbid, clear  Malodorous, normal odor  Reddish, brown or normal colored  pH-acidic, alkaline, neutral  Protein-usually present  Leukocyte esterase usually positive  RBCs-present, or absent

DIAGNOSIS URINANALYSIS (MICROSCOPY)  Numerous pus cells/HPF  RBCs variable  Motile or non motile bacilli are visible on direct examination  Presence of casts indicates??

DIAGNOSIS URINE CULTURE & SENSITIVITY  Proper urine sampling  Clean catch, midstream urine  Must be cultured within 30 min  Problems in children, catheterized patient

DIAGNOSIS  Semi-quantitative (single org >10 5 /ml or urine  Antimicrobial sensitivity  Results informed to physician  Patient put on therapy  hrs procedure  Empiric therapy in serious cases

MANAGEMENT  Improve hydration & encourage plenty of fluids  Pain killers for pain and aches  Antimicrobials if indicated  Empiric antimicrobials according to available data of hospital  Later confirm with Urine C/S results  Uncomplicated cystitis usually 3 days course of Nitrofurantoin, Trimethoprim/sulfamethoxazole, Ciprofloxacin or Co-amoxiclav