Pathophysiology urinary tract infections

etiology, types, pathogenesis, sign and symptoms of urinary tract infection

1. Pathophysiology urinary tract infections Nem Kumar Jain MS (Pharm.) Pharmacology & Toxicology Assistant Professor, School of Pharmacy ITM University Gwalior

2. Introduction Urinary tract infections (UTIs) can be divided into Upper tract infections, which involve the kidneys ( Pyelonephritis ), Lower tract infections, which involve the bladder (Cystitis), urethra ( Urethritis ), and prostate ( Prostatitis ).   Although urethritis and prostatitis are infections that involve the urinary tract, the term UTI usually refers to pyelonephritis and cystitis . Symptomatic presence of microbes and associated inflammation in urinary tract

3. Epidemiology Among adults aged 20 to 50 years, UTIs are about 50-fold more common in women. In women in this age group, most UTIs are cystitis or  pyelonephritis . In men of the same age, most UTIs are  urethritis  or  prostatitis . The incidence of UTI increases in patients > 50 years, but the female:male ratio decreases because of the increasing frequency of prostate enlargement and instrumentation in men. types Uncomplicated UTIs: UTIs that occur in premenopausal adult women with no structural or functional abnormality of the urinary tract and who are not pregnant and have no significant comorbidity that could lead to more serious outcomes . Complicated UTI: A UTI is considered complicated if the patient is a child, is pregnant, or has any of the following: A structural or functional urinary tract abnormality and obstruction of urine flow A comorbidity that increases risk of acquiring infection or resistance to treatment, such as poorly controlled diabetes, chronic kidney disease, or immunocompromise Recent instrumentation or surgery of the urinary tract Recurrent UTIs: >3 symptomatic UTIs within 12 months following clinical therapy

4. Etiology Most cystitis and pyelonephritis are caused by bacteria. The most common nonbacterial pathogens are fungi (usually candidal species), and, less commonly, mycobacteria , viruses, and parasites. Nonbacterial pathogens usually affect patients who are immunocompromised ; have diabetes, obstruction, or structural urinary tract abnormalities; or have had recent urinary tract instrumentation . Bacterial UTIs: Gram negative: Escherichia coli (75-95% of cases), enterobacteria , typically  Klebsiella  or  Proteus mirabilis , and occasionally   Pseudomonas aeruginosa Gram positive: Staphylococcus saprophyticus , Enterococcus faecalis  (group D streptococci) and  Streptococcus agalactiae   In hospitalized patients,  E. coli  accounts for about 50% of cases. The gram-negative species  Klebsiella ,  Proteus ,  Enterobacter ,  Pseudomonas , and  Serratia  account for about 40%, and the gram-positive bacterial cocci   E. faecalis ,  S. saprophyticus , and  Staphylococcus aureus  account for the remainder. Why do women get UTIs more often than men? Shorter urethra, and opening closer to anus

5. Risk Factors Sexual intercourse Diaphragm and spermicide use Antibiotic use New sex partner within the past year History of UTIs in 1st-degree female relatives History of recurrent UTIs First UTI at early age Ageing: urine retention, diabetes, impaired immune system, catheterization PATHOGENESIS Ascending Infection: most common route, microbes colonize in periurethral and perinial areas and ascends bladder to kidney Hematogenoous spread: bacterimea (staphylococcus aureus ) blood borne spread to kidney Lymphatogenous spread Direct extension from other organs: prostatis

6. Pathogenesis

7. Sign and symptoms

8. Prevention is better than cure