Genitourinary Infections: Chapter 26- Genitourinary Infectionso very commono UTI (urinary tract infection): most common nosocomial infections and the chief source of fatal nosocomial bacterial bloodstream infectionso STD (sexually-transmitted diseases): United States leads industrialized nations in reported incidence of sexually transmitted diseases- Urinary System Infectionso Urinary tract infections  may include any or all of the organs of the urinary system any situation interfering with urine flow increases risk of infection- Bacterial Cystitsi (Infection of the Bladder)o urinary bladder inflammationo Symptoms burning pain on urination frequent urination (polyuria/nocturia) cloudy urine foul or strong odor urine can be pale red due to presence of blood can be asymptomatic- especially among children and elderlyo Complications pyelonephritis = pathogen travels up urethra to kidney- sudden fever- chills- vomiting- back pain repeated pyelonephritis can scar and shrink the kidney – impt cause of later kidney failureo Epidemiology ~ 30% of women develop cystitis during lifetime- usually by coliforms transferred from bowel to urethra into bladder factors:- short (a few cm to bladder) urethra => easy colonization through fecal contamination- sexual intercourse In men, cystitis is unusual- generally after age 50- associated with enlarged prostate => slows urine flow Catheterization increases risk- Colonization of bacteria on catheter make killing organisms nearly impossibleo 500,000 hospitalized patients develop bladder infections from catheterization Causative Agent- in women, infection usually originates from normal intestinal flora - 80-90% E. coli in healthy women during reproductive years- long-term catheterization => very common- Gram-negatives Pseudomonas aeruginosa, Serratia marcescens, Gram-positive Enterococcus faecalis Pathogenesis- pathogen travels up urethra to bladder- urine = good growth medium- bacteria attach to receptors on bladder lining, epithelium sloughs off, bacteria enter exposed cells by endocytosis- pyelonephritis when bacteria ascend ureters and damage kidney- Candidiasis (Vaginal yeast infection)o Staphylococcal Toxic Shock Syndrome otherwise healthy individual high fever, rash, low blood pressure, confusion => stupor, coma, organ failure superantigen toxin TSST-1 => nonspecific binding of MHC II with T cell receptors => massive immune response frequently requires ICU admission most recover but can be fatal within hourso Symptoms most common itching burning, redness, swelling vaginal dischargeo Causative Agentfungus (eukaryote) Candida albicans part of normal flora in ~;35% of womeno Pathogenesis C. albicans normally causes no symptoms due to balance between organism and normal vaginal flora When balance upset fungi multiply causing inflammatory response and symptomso Epidemiology not contagious antibacterial medications increase risk of diseaseo Treatment minimize use of antibiotics intravaginal antifungal medications are most effective e.g. Nystatin usually effective oral Fluconazole (Diflucan)Sexually Transmitted Diseases (STD)- Gonorrhea…o second most common notifiable STD in the USo Symptoms incubation period 2 to 5 days post exposure long-lasting, asymptomatic infection can occur on both sexes In men- urethritis with painful urination- thick pus-containing discharge from penis In women- ~half are asymptomatic- others have mild vaginal discharge - => may be overlookedo Causative Agent  Neisseria gonorrhoeae- Gram-negative diplococcus- attaches to epithelial cells with their pili- attaches to sperm- genetic “defense” strategies well-studiedo phase variation of pili pilin genes off/on cells attach/detacho antigenic variation of pili pilin gene rearrangementso Complications untreated men can develop:- urinary tract infections- orchitis (inflammation of testicle)- prostate abscesses- sterility if scar tissue blocks route of sperm untreated women:- N. gonorrhoeae grows well in cervix and fallopian tubes- 20-30% women develop pelvic inflammatory disease (PID) = infection of fallopian tubes- scar tissue there leads to increased risk of ectopic pregnancy, sterility Systemic dissemination- N. gonorrhoeae grows in skin pustules, in joints, heart, meninges In infants: opthalmia neonatorum- “gonococcal conjunctivitis of the newborn”- acquired in ~30% of infants from infected birth canal in symptomatic/asymptomatic mother- destructive infection: attacks cornea- prophylactic treatment of eyes with erythromycin at birth is legally mandated - Chlamydia (most common bacterial STD) o a high % of those infected with gonorrhea are also infected with Chlamydiao Symptoms  generally appear in 7 -14 days easily mistaken for gonorrhea since symptoms are similar more common than gonorrhea notifiable (reportable) disease only since 1995 often asymptomatic in men and women numbers of cases rising In men- thin grayish-white discharge from penis- some have painful testes In women- vaginal discharge- painful urination - abnormal abdominal bleeding- abdominal paino Causative AgentChlamydia trachomatis- spherical- obligate intracellular bacterium- attaches to sperm- several antigenic types responsible for STD- (some other types responsible for trachoma blindness)o Pathogenesis C. trachomatis infectious form = “elementary body” taken up into epithelial cells of the mucosa by endocytosis multiply inside infected cells which release cytokines => cell-mediated immune response => tissue damage women- commonly involves cervix, uterus and fallopian tubes- => PID - chronic pain- scarring causes ectopic pregnancy or sterility men- infection spreads from urethra to tubules which collect sperm from testicles- => acute pain and swellingo Newborns during passage through birth canal chlamydial opthalmia conjunctivitis much like with gonorrhea  also C. trachmatis pneumonia o Prevention and Treatment  azithromycin effective single dose treatment doxycycline/tetracycline, erythromycin less expensive