Kidney and Urinary Tract Disease - Urinary Tract Infections (33) Flashcards
Where is sterile flora in urinary tract?
Kidneys, ureters, bladder (except in UTI)
What flora is in urethra?
Perineal flora - skin/lower GI tract
Skin flora
Coagulase-negative staphylococci
Lower GI tract flora
(Anaerobic bacteria), Aerobic bacteria (Enterobacteriaceae - gram -ve bacilli/coliforms), gram positive cocci (eneterococcus)
Clinical classification of UTI
- Cystitis
- Pyelonephritis
- Urethral syndrome
Microbiological classification of UTI
- Significant bacteriuria
- Asymptomatic bacteruria
- Sterile pyuria
Where does cystitis effect?
Lower urinary tract - bladder
Cystitis symptoms
Dysuria, urinary frequency, urgency, supra-pubic pain/tenderness, polyuria, nocturia, haematuria
Where does pyelonephritis effect?
Upper urinary tract - kidneys/renal pelvis
Pyelonephritis symptoms
Lower UTI, loin/abdominal pain/tenderness, fever, systemic infection (rigors, nausea, vomiting, diarrheoa, elevated CRP, WBC)
What is urethral syndrome?
Symptoms of lower UTI without infection
Who does urethral syndrome common effect?
Women 30-50 years
Urethral syndrome can also be called
Abacterial cystitis or frequency-dysuria syndrome
Significant bacteriuria
Kass criteria, 10^5 cfu/mL
Limitations of significant bateriuria criteria
- Count is on a normal curve
- Symptomatic females bacterial counts
Asymptomatic bacteriuria
Significant bacteriuria (single organism), no symptoms
Sterile pyuria
Pus cells in urine, no organisms grown (antibiotics inhibit bacterial growth)
Causes of sterile pyuria
Inflammation (kidney stones, trauma, polycystic kidney disease, ‘fastidious’ organisms
Causative organisms of sterile pyuria
M. TB, haemophilus, N.gonorrhoea, anaerobes
Predisposing factors
- Female 10:1
- Pregnancy, prostatic hypertrophy, stones, strictures, neoplasia, residual urine
- Instrumentation
- Sex
- Fisutale (recto-vesical/vesico-vaginal)
- Congenital abnormalities (Vesico-ureteric reflux)
Sources of infection
- Perineum
- Fistulae
- Haematogenous
Organisms that cause UTI
- E. coli (80%)
- Staph saprophyticus (honeymoon cystitis)
- Proteus mirabilis
- Enterococcus
- Klebsiella
- Coliforms
- Pseudomonas aeruginosa
Investigations
- Dipstick testing
- Blood tests
- Microbiology
- Imaging
Dipstick
Test for blood, protein, nitrite, WBC (leucocyte esterase)
Microbiology - urine
Mid-stream, catheter, ‘clean catch’, supra-pubic aspirate (M, C&S)
Bloods
Suspected pyelonephritis
Imaging
Renal tract USS, isotope scan (DMSA, DTPA, MAG3), micturating cystourethrogram
Early morning urine
(EMU) X 3, whole contents of bladder, if suspected TB
Examples of UTI antibiotics
Nitrofurantoin, Pivmecillinam, Trimethoprim, Fosfomycin
Cystitis treatment
Females - 3 days, Males - 7 days
Pyelonephritis treatment
IV antibiotics - Cefuroxime, ciprofloxacin, Piperacillin-tazobactam (>65 years)
7-14 days
When should you treat asymptomatic bacteriuria?
Pregnant - associated with upper UTI, pre-term delivery, low birth weight
Infant - prevent pyelonephritis and renal damage
Prior to urological procedures - prevent UTI
When should you not treat asymptomatic bacteriuria?
Elderly or catherterised
