尿路感染英文教學課件

1、Urinary Tract InfectionDefinition: A urinary tract infection, or UTI,is an inflammation of the urinary tract caused by a bacterial infection. at least 100,000 colony-forming units (cfu) organisms per milliliter from a pure culture of voided clean-catch urineThe female and male urinary tracts are bas

2、ically the same except for the length of the urethra.The female and male urinary tracts are basically the same except for the length of the urethra.ClassificationAscending urinary infectionsPyelonephritis Kidney symptomsCystitis - Bladder symptomsUrethritis - Urethral symptoms Upper UTI: Pyelonephri

3、tis ( bacteremia): acute or chronicLower UTI: Urethritis, Cystitis (approx. 30% occult pyelonephritis)Complicated UTI is a urinary tract infection in a patient with a functionally, metabolically, or anatomically abnormal urinary tract, including: Foreign body (catheter, stent) Obstruction (calculi,

4、congenital anomaly, prostatic disease, stricture, tumor)Uncomplicated UTI: Healthy,Nonpregnant,Nonobstructed, young femalesEpidemiology After infancy, urinary tract infections occur more often in females because the :- 1. urethra is shorter and 2. closer to the anus. 3.lack of prostatic secretions.

5、In women the urethra opens at the perineum- a site rich in potentially pathogenic flora eg. Enterobacteriaceae.Epidemiology of UTIUTI is very common, especially among women and the elderly.The majority of the cases seen are in women (8:1, female:male ratio). 40% of all women have at least one episod

6、e of a UTI at some time in their lives; 20% of young women with acute cystitis develop recurrent UTIs. Males experience a rapid increase in the incidence of UTIs sometime in their 50s due to prostate gland hypertrophy. Etiology Many different microorgnism can infect UT, the most commom agents are th

7、e gram-negative bacilli gram-positive cocci play a lesser role in UTIsEscherichia coligram (-) etiologic agent in 80%85% of all UTIsStaphylococcus saprophytism is the cause in 510%.Research indicates primary source of microbial invasion is retrograde colonization by intestinalCausative PathogensComm

8、on causes of UTIStaphylococcussaprophyticusEscherichia coliKlebsiellaProteusAcute uncomplicated cystitisNatural Host Defense Mechanisms-Urinary hemodynamics: large urinary flow flush and dilutes bacteria and eliminates them from system -Acidity: pH 10 leukocytes /hp (pyuria) Nitrite (Enterobacteriac

9、eae converts urinary nitrate to nitrite. ) WBC casts diagnostic for pyelonephritisHematuria is common with UTIThe presence of excess neutrophils greater than 10 per mm3 (pyuria) by microscopic analysis is evidence of infection WHEN accompanied with bacteriuria.Probable UTI - Bacteria and white blood

10、 cellspresent.DiagnosisUrine Culture important to confirm and tailor antibiotic.Considered positive 100,000 CFU/mL 100 -10,000 CFU (acute symptoms +pyuria) Negative culture or consider contaminated 3 organisms Not always necessary in typical uncomplicated UTI expensiveSemiquantitative cultureUrine culture - 105 colony forming units per ml of a SINGLE organism differentiates infection (significant bacteriuria) fro