12 - UTI Flashcards
What is cystitis?
Infection of bladder and/or ureters (lower urinary tract)
What are the most common pathogens in acute cystitis?
- E. coli
- Staph saprophyticus (CoNS), Klebsiella spp, proteus mirabilis
Defences of the urinary tract
- pH, osmolality, urea, organic acids
- Epithelial glycosaminoglycan
- IGs
- Bacterial adherence and virulence factors
Risk factors for acute cystitis
- Female, particularly previous UTI, sexually active, pregnant, or post-menopausal
- Obstruction (BPH), urinary reflux, incontinence, urinary catheter
- Diabetes, immunocompromised
What is the clinical presentation of acute cystitis?
- 90% probability w/ 2 of dysuria, urinary frequency or urgency
- May have suprapubic pain, mild hematuria, or cloudy urine
- Atypical presentation on elderly (confusion, agitation, GI sx)
Describe differential diagnosis of acute cystitis
- Pyelonephritis (fever, chills, N/V, flank pain)
- Vaginitis (discharge, odour, pruritus)
- Acute urethritis/STI (dysuria, no frequency or urgency)
- PID/STI (discharge, dysuria, pelvic pain, fever)
- Drug induced cystitis (allopurinol, cyclophosphamide, danazol)
Describe diagnostic testing involved in urinalysis
- Microscopic > 10^5 cfu/mL
- Chemistry (dipstick test) for nitrite, leukocyte esterase; positive nitrite and leukocyte esterase test specific for bacteriuria
- Microscopic pyuria > 10 cells/uL
When are urine cultures done?
- Tx failure
- Relapse
- Complicated infection (children, pregnancy, males)
What factors indicate potentially complicated acute cystitis?
- Male, pregnancy, children < 16 y/o
- Relapse
- Urinary lesion, catheter, obstruction, neurogenic bladder
- Immunocompromised (HIV, lymphoma, leukemia, uncontrolled diabetes, immunosuppressants)
What is the problem w/ dipstick tests?
Often produce false-negatives when gram pos or P. aeruginosa are present b/c they don’t reduce nitrate to nitrite
What is pyuria?
- WBC greater than 10^6 per L
- Signifies inflammation and not necessarily infection
What is the significance of complicated acute cystitis?
- Higher risk of multiple and/or antimicrobial-resistant pathogens
- Antimicrobial therapy x 1-2 weeks (per urine culture/ susceptibilities and pt characteristics)
Antimicrobial options for acute uncomplicated cystitis
- Nitrofurantoin 100 mg q12h x 5 days
- TMP-SMX 160/800 (DS) q12h x 3 days
- [Amox-clav 875/125 q12h x 7 days]
- [Cephalexin 500 q6h / cefprozil x 7 days]
- [Fosfomycin 3 g x 1 dose]
Indication of nitrofurantoin
- Mild-moderate cystitis
- Not for treating systemic infections b/c concentrates in urine and doesn’t have good plasma concentrations
When should nitrofurantoin not be used?
- Clcr < 30 mL/min
- Pregnancy at term > 36 weeks
- Neonates < 1 month (displaces bilirubin, which would cause or worsen jaundice in newborn/ neonate)
- Glucose-6-phosphate dehydrogenase deficiency
Indication of TMP-SMX
Mild-moderate cystitis (E. coli, klebsiella spp, proteus spp, S. aureus)
When should TMP-SMX not be used?
- E. coli resistance > 20%
- Clcr < 10-15 mL/min
- Pregnancy
- G6PD deficiency
Can fluoroquinolones be used for acute uncomplicated cystitis?
- Use is reserved for moderate-severe or complicated infection
- Not recommended for children or pregnancy
Typical response for tx of acute uncomplicated cystitis
- Urinary sx improved w/in 1 day
- Resolution w/in 3 days
Indication of fosfomycin
Mild-moderate cystitis associated w/ E. coli or E. faecalis
What is the difference between relapse and recurrence?
- Relapse = re-infection w/ same organism w/in 2 weeks
- Recurrence = 2 infections w/in 6 months or 3 or more infections w/in 12 months
What should be done for relapse of cystitis?
- Urine culture to identify potentially resistant pathogen and for possible pyelonephritis
- Re-treat as described for acute cystitis, consider longer duration
What should be done for recurrent cystitis?
- Treat as described for acute uncomplicated cystitis
- For frequent recurrences, urine culture and work-up for underlying medical conditions
- Prophylaxis not generally recommended
Antimicrobial therapy for treating acute cystitis in pregnancy
- Nitrofurantoin, amox-clav (amox if susceptible), or cephalexin (cefixime, cefprozil if susceptible) x 7 days
- Urine culture and confirm tx success w/ follow-up culture
Approach to tx of acute cystitis in children
- Urine culture and confirm tx success w/ follow-up culture
- Work-up for pyelonephritis, underlying medical condition, or anatomical anomaly
- Amox-clav, cephalexin (cefixime if susceptible), nitro, or TMP-SMX
Tx for pyelonephritis in children
Gent +/- ampicillin or ceftriaxone IV
What is asymptomatic bacteriuria?
Bacteria counts of 10^5 cfu/mL or greater in urine w/o signs of infection
Tx for asymptomatic bacteriuria
- Antimicrobial therapy x 3-7 days in pregnant women and prior to traumatic urologic procedures
- Antimicrobial therapy may be indicated for immunocompromised (not diabetes, advanced age, nursing home, spinal cord injury, or catheter)
Why are pregnant women treated for asymptomatic bacteriuria?
- Can lead to pyelonephritis
- Can transfer to infant during delivery (like group B strep in birth canal)
What is the relevance of catheter-associated UTI?
- Bacteruria rate of 3-10% per day of catheterization
- Often polymicrobial involving atypical and MDR organisms
- Signs of infection
What is the tx for catheter-associated UTI?
- Remove or replace catheter
- Antimicrobial therapy for at least 7 days as per culture/ susceptibilities
Most common pathogens of pyelonephritis
- E. coli
- Klebsiella spp, P. mirabilis, S. saprophyticus, S. aureus, enterococcus spp
Risk factors for acute pyelonephritis?
- Acute cystitis, previous pyelonephritis
- Elderly, pregnancy, diabetes, immunocompromised
- Anatomical abnormalities, neurological/ muscular disease
- Lesions or obstructions
What factors constitute complicated pyelonephritis?
- Male, pregnancy, children < 16 y/o
- Relapse
- Urinary lesion, catheter, obstruction, neurogenic bladder
- Immunocompromised (HIV, lymphoma, leukemia, uncontrolled diabetes, immunosuppressants)
- Urosepsis (bacteremia) w/ significant signs of infection
Clinical presentation of acute pyelonephritis?
- Fever, chills, N/V, flank pain
- Leukocytosis, hypotension, tachycardia
Antimicrobial options for mild-moderate pyelonephritis? PO or IV?
- PO
- Cipro 500-750 mg q12h or 1 g x 7 days
- Levo 500 mg q24h x 7 days or 750 mg q24h x 5 days
- [TMP-SMX x 7-14 days]
- [Amox-clav x 7-14 days]
Antimicrobial options for moderate-severe pyelonephritis? PO or IV?
- PO or initial IV w/ PO step-down
- Cipro 400 mg q12h (IV)
- Levo 500-750 mg q24h x 7-14 days
- TMP-SMX 160/800 q12h x 7-14 days
Antimicrobial options for severe or hospital-acquired pyelonephritis? PO or IV?
- IV
- Gent +/- ampicillin (for enterococcus coverage)
- Ceftriaxone
- Pip-tazo (has enterococcus coverage)
- Mero/ertapenem
Response to tx for acute pyelonephritis
- Clinical improvement w/in 1-2 days
- Resolution w/in 3-4 days
Signs and sx of acute prostatitis
Sudden onset fever, tenderness, and urinary sx
Most common pathogens of acute prostatitis
Gram-neg enteric organisms
Tx for acute prostatitis
- Good tx response
- Cipro/ levo or TMP-SMX (per susceptibilities) x 4 weeks
- Severe infection may require initial IV therapy
Signs and sx of chronic prostatitis
- Complication of recurrent infections
- Urinary sx including lower back pain or pressure
Most common pathogen in chronic prostatitis
E. coli
Tx for chronic prostatitis
- Poor tx response b/c low antimicrobial penetration into prostatic fluid
- Cipro/ levo or TMP-SMX for at least 4-6 weeks (per susceptibilities)
- May also require chronic suppressive therapy or surgery
