Genitourinary Infections Chapter 26 Genitourinary Infections o very common o UTI urinary tract infection most common nosocomial infections and the chief source of fatal nosocomial bacterial bloodstream infections o STD sexually transmitted diseases United States leads industrialized nations in reported incidence of sexually transmitted diseases Urinary System Infections o Urinary tract infections Bacterial Cystitsi Infection of the Bladder o urinary bladder inflammation o Symptoms may include any or all of the organs of the urinary system any situation interfering with urine flow increases risk of infection 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 elderly o Complications pyelonephritis pathogen travels up urethra to kidney sudden fever chills vomiting back pain o Epidemiology factors repeated pyelonephritis can scar and shrink the kidney impt cause of later kidney failure 30 of women develop cystitis during lifetime usually by coliforms transferred from bowel to urethra into bladder 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 impossible o 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 hours C albicans normally causes no symptoms due to balance between organism and normal vaginal When balance upset fungi multiply causing inflammatory response and symptoms o Symptoms most common itching burning redness swelling vaginal discharge o Causative Agent fungus eukaryote Candida albicans part of normal flora in 35 of women o Pathogenesis flora o Epidemiology o Treatment not contagious antibacterial medications increase risk of disease 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 US o 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 overlooked o Causative Agent Neisseria gonorrhoeae Gram negative diplococcus attaches to epithelial cells with their pili attaches to sperm genetic defense strategies well studied o phase variation of pili pilin genes off on cells attach detach of pili o antigenic variation pilin gene rearrangements o 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 Chlamydia o 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 pain o 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 taken up into epithelial cells of the mucosa by endocytosis C trachomatis infectious form elementary body 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 o Newborns acute pain and swelling 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 alternatives