URINARY TRACT INFECTION Dr.Mohammed Sharique Ahmed Quadri Assistant professor Almaarefa College

LEARNING OBJECTIVES Cite organisms most responsible for urinary tract infections (UTIs) and state why urinary catheters, obstruction, and reflux predispose to infections.  List three physiologic mechanisms that protect against UTIs.  Compare the signs and symptoms of upper and lower UTIs.   Describe factors that predispose to UTIs in children, sexually active women, pregnant women and older adults. Compare the manifestations of UTIs in different age groups, including infants, toddlers, adults, and older adults. Cite measures used in the diagnosis and treatment of UTIs.

ANATOMY

Urinary Tract Infections UTI Includes Asymptomatic bacteriuria Symptomatic lower UTI e.g. Acute cystitis Upper UTI e.g. Acute pyelonephritis

Epidemiology of UTI UTI is more common in females. (1-2% of young non-pregnant women) 40% of females will have a symptomatic UTI in their life time. In men: prevalence is 0.04%. Incidence of UTI increases in old age. (10% of men & 20% of women)

Routs of infection Ascending infection from the urethra is the most common route. Pyelonephritis most commonly results from ascent of infection up the ureter. Hematogenous spread to the urinary tract is uncommon, the exceptions being tuberculosis and cortical renal abscesses. Lymphogenous spread is rare. Direct extension from other organs may occur, especially from intraperitoneal abscesses in inflammatory bowel disease or pelvic inflammatory disease.

Risk factors for UTI In Females: In Males: sexual activity ,use of spermicidal, diaphragm Pregnancy. Estrogen deficiency (Post menopausal ) In Males: lack of circumcision, prostatic hypertrophy,

Risk factors for UTI In both sexes : Obstruction, Vesicoureteric reflux, Instrumentation, & catheterization Neurogenic disorders that impairs bladder, emptying Diabetes (increase risk of complications and fungal infections)

Risk factors for UTI Obstruction : any microorganism that enter the bladder is washed out during voiding. When outflow is obstructed Urine remains in bladder – medium for microbial growth Increase pressure in bladder- compresses vessels in bladder wall- decrease in the mucosal defense

Risk factors for UTI Obstruction : Anatomic Obstruction Stones Prostatic hyperplasia Pregnancy Malformation of ureterovesical junction Functional obstruction Neurogenic bladder Infrequent voiding Constipation Detrusor muscle instability

Risk factors for UTI Urethrovesical reflux : urine from urethra moves into bladder In women during coughing or squatting Voiding abruptly interrupted Vesicouretral reflux: occurs at the level of bladder and ureter Due to abnormality at the junction of ureter & bladder Associated with pyelonephritis and infection of upper urinary tract

Risk factors for UTI CATHETER INDUCED INFECTION: Provide A means for entry of microorganisms into the urinary tract Bacteria adhere to surface of catheter & initiate the growth of biofilm that covers the surface of catheter. Biofilm protects the bacteria from antibiotics

Etiological Factors Uncomplicated Lower UTI Complicated UTI Escherichia Coli Staphylococcus saprophyticus Complicated UTI Proteus mirabilis Klebsiella species Enterobacter species Pseudomonas aeruginosa Staphylococcus aureus (gram- positive cocci) Gram negative rods

Pathogenesis of UTI PATHOGEN VIRULANCE HOST DEFENSES Pathogenesis of UTI involves interaction of host with agent .leading to letdown of host defenses against virulence of infectious agents

Pathogenesis of UTI Host Defenses: Urinary bladder is usually resistant to bacterial colonization. Host defences of bladder have many components. Washout Phenomenon: Bacteria removed during voiding Protective mucin layer: Protects against bacterial invasion Immune mechanisms: secretory immunoglobulin(IgA), PMN cells Normal flora in periurethral area in women and prostatic secretion in males

Pathogen Virulance Only those strains of E-coli with increased ability to adhere to epithelial cells , produce UTI Most E.coli causing UTI belong to O,K and H serotypes. Uropathogenic E.coli virulence factors: - Have fimbria /Pilli (for adherence). - Secrete hemolysin & aerobactin. - Resist serum bactericidal action.

Pathogenesis of UTI Periutheral area & urethra are colonised by bacteria. Bacteria enter bladder in susceptible host. Adherence properties enable pathogens to colonise bladder. Pathogens attach to uroepithelial mucosa  secretion of cytokines  recruitment of PMNs  inflammation. Pathogens may ascend through ureter to kidney  pyelonephritis.

Clinical presentation of UTI Asymptomatic bacteriuria: Common in females & elderly. 25% develop symptomatic UTI . 25% clear spontaneously. Spontaneous cure & reinfection are common. Cystitis: Frequency, dysuria , urgency. Suprapubic discomfort +/- tenderness. Fever is often absent. Ocasionally urine is cloudy and foul smelling

Clinical presentation of UTI Acute pyelonephritis: Fever, abdominal pain, vomiting. Dysuria ,frequency, flank or loin pain. Flank or loin tenderness. In elderly: symptoms are often atypical. Bacteremia is common.

UTI in Special Populations

UTI in Pregnant women Changes occurring in urinary tract during pregnancy predispose to UTI Dilation of calyces, pelvis and ureters. Reduction in peristaltic activity of ureters (thought to be muscle relaxing effect of progesterone and mechanical obstruction from enlarge uterus)

UTI in Pregnant women Complications: Persistent bacteriurea UTI during pregnancy may be the result of preexisting asymptomatic bactriurea Urine culture is recommended at first prenatal visit Acute or chronic pyelonephritis premature delivery. low birth weight infant. Increased newborn mortality

UTI in Children

Frequency of UTI UTI is more frequent in females than males at all ages with the exception of the neonatal period. Uncircumcised males have a higher incidence than circumcised males. Uncircumcised male infants have a higher incidence of UTI than female infants.

Frequency of UTI Excluding neonates, females younger than 11 years have a 3-5% risk; boys of the same age have a 1% risk. UTI is the source of infection in up to 6-8% of febrile infants in the first 3 months of life.

Clinical Features vary with the age of the patient. Symptoms in Neonates: Hypothermia or fever Failure to thrive Poor feeding Vomiting Symptoms in Infants: Fever Vomiting, diarrhea Strong-smelling urine

Clinical Features Preschoolers School-aged children Vomiting, diarrhea, abdominal pain Fever Strong-smelling urine, enuresis, dysuria, urgency, frequency School-aged children Vomiting, abdominal pain Strong-smelling urine, frequency, urgency, dysuria, flank pain, or new enuresis Adolescents are more likely to have some of the classic adult symptoms.

Complications Even in the absence of urinary tract abnormalities, cystitis may lead to vesicoureteral reflux, and it may worsen a pre-existing reflux. Untreated reflux causes pyelonephritis. Chronic or recurrent pyelonephritis results in renal damage and scarring that may progress to chronic renal failure. Prevalence varies based on age and sex

UTI IN ELDERLY

UTI IN ELDERLY Second most common cause of infection after respiratory tract infection. Predisposing factors: Immobility leading to poor bladder emptying Obstruction (BEP, stones) Bladder ischemia caused by urinary retention Constipation Senile vaginitis Other problems necessitating catheterisisation.

UTI IN ELDERLY Varying symptoms. Difficult to interpretate because elderly people without UTI also commonly experiences, urgency, frequency and incontinence. May have vague symptoms like Anorexia Fatigue Weakness

DIAGNOSIS

Diagnosis of UTI Urine microscopy: -WBCs, RBCs Urine dipstick: - more markers of infection

Diagnosis of UTI Urine culture & sensitivity to antibiotics Significant bacteriuria= 100000 cfu/ml symptoms: 1 +ve cuture = infection Symptoms: 10000 cfu/ml = propable infection Asymptomatic: 2 +ve cultures = infection False negative : antibiotics, antiseptics, diuresis.

Diagnosis of UTI Others CBC, BLOOD CULTURE KIDNEY FUNCTION TEST X-ray Ultrasonography CT scan Renal scans Used to identify Contributing factors like obstruction