UTI Flashcards
When is screening and treatment of ASB indicated and why?
- pregnant women
- prevent pyelonephritis, preterm labour, infant low birth weight - patients undergoing urologic procedure where mucosal trauma/bleeding is expected (surgical antimicrobial prophylaxis)
- prevent bacteremia and urosepsis
- does not include placement/removal of catheter
What is the definition of ASB?
Asymptomatic bacteriuria (ASB): isolation of significant colony counts of bacteria in the urine of patient without symptoms of UTI
What is the definition of UTI?
Urinary Tract Infection (UTI): isolation of significant colony counts of bacteria in the urine of a patient with symptoms of UTI
Name the risk factors for UTI
Females > males, sexual intercourse, use of spermicides/diaphragms as contraceptives, abnormalities of the urinary tract (e.g. prostatic hypertrophy, kidney stones, urethral strictures, vesicoureteral reflux), neurologic dysfunctions (e.g. stroke, DM, spinal cord injuries), catheterization, anti-cholinergic drugs, DM, immunocompromised, pregnancy, genetic association (women with first degree relatives), previous UTI
Name the criteria for uncomplicated UTI?
UTI in healthy, pre-menopausal, non-pregnant women who do not have history suggestive of an abnormal urinary tract.
Name those that can be considered to have complicated UTI?
Complicated UTI (maybe complicated cystitis or complicated pyelonephritis)
Men
Children
Elderly
Pregnant women
Women (pre-menopausal), but with recurrent (relapse within 2 weeks) or frequent UTI
Women (pre-menopausal), but with risk factors, e.g. DM, immunocompromised, functional and structural abnormalities in the urinary tract, genitourinary instrumentation
Nosocomial/healthcare-associated UTI
CA-UTI
Describe the clinical presentation (signs and symptoms) of lower urinary tract infection?
dysuria, increased frequency, increased urgency, nocturia, suprapubic pain/heaviness, gross hematuria
elderly with recurrent UTI may present with non-specific symptoms such as: anorexia/loss of appetite, altered mental status, drowsiness, decreased alertness, mild gastrointestinal symptoms
Describe the clinical presentation (signs and symptoms + labs) of upper urinary tract infection?
fevers, rigors, malaise, headache, tachypnea, tachycardia, nausea, vomiting, abdominal pain, flank pain, positive renal punch (costovertebral pain; indicates a swollen and tender kidney)
labs for general systemic infection/inflammation:
elevated WBC, pro-calcitonin, C-reactive protein
Name the types of urine tests done to diagnose for UTI?
UFEME (microscopic urinalysis)
Urine dipstick test (chemical test)
Urine culture
Describe the findings from UFEME (microscopic analysis; Urine Formed Elements and Microscopic Examination) that indicate positive for UTI?
WBC > 10 cells/mm^3 (pyuria; in a symptomatic patient, absence of pyuria = unlikely UTI), RBC > 5 cells/HPF or gross (hematuria; frequently occurs in UTI, but have other causesu), presence of bacteria/yeast cells identified, presence of WBC casts (presence of WBC casts indicates upper urinary tract infection)
note: presence of squamous epithelial cells indicate contaminated sample
Describe the findings from urine culture (microscopic analysis) that indicate positive for UTI?
Positive urine culture
Describe the findings from urinary dipstick test (chemical urinalysis) that indicate positive for UTI?
Positive for nitrite (indicates presence of gram-negative bacteria that reduces nitrate to nitrite), positive for leukocyte esterase (indicates presence of leukocytes in urine, correlates with pyuria)
Outline the rationale for when to obtain urine cultures for UTI
Complicated UTI (may be complicated cystitis or complicated pyelonephritis, doesn’t matter) > need to take culture
Men
Children
Elderly
Pregnant women
Women (pre-menopausal), but with recurrent (relapse within 2 weeks) or frequent UTI
Women (pre-menopausal), but with risk factors, e.g. DM, immunocompromised, functional and structural abnormalities in the urinary tract, genitourinary instrumentation
Nosocomial/healthcare-associated UTI
CA-UTI
Uncomplicated UTI: healthy, pre-menopausal women with no history suggestive of anatomical/functional/structural deficits in the urinary tract
- uncomplicated cystitis > no need to take culture
- uncomplicated pyelonephritis > need to take culture
What is the likely pathogen causing community-acquired UTI?
E.coli (>85%)
Staphylococcus saprophyticus,
Enterococcus fecalis
Klebsiella spp.
Proteus spp.
What is the likely pathogen causing healthcare associated UTI (including catheter-associated UTI)? (healthcare-associated UTI will be considered complicated UTI)
E. coli (~50%) (incl. ESBL producing)
Enterococcus fecalis
Klebisiella spp. (incl. ESBL producing)
Proteus spp. (incl. ESBL producing)
Enterobacter spp. (incl. Amp-C producing)
Pseudomonas aeruginosa
What does the presence of S. aureus in urine culture suggest?
hematogenous infection (commonly due to bacteremia), to screen for other primary infection sites
What does the presence of yeast/candida in urine culture suggest?
possible contaminant
What are the categories for empiric treatment for different types of UTI? (including pregnant women)
community-acquired cystitis in women
community-acquired cystitis in men
community-acquired pyelonephritis in women
community-acquired pyelonephritis in men
nosocomial/healthcare-associated UTI
catheter-associated UTI (CA-UTI)
ASB in pregnant women
community-acquired cystitis in pregnant women
community-acquired pyelonephritis in pregnant women
nosocomial/healthcare related UTI in pregnant women
Describe the adjunctive therapy for UTI
For pain and fever, treat using paracetamol/NSAIDs
For vomiting, provide rehydration
For urinary symptoms, treat using:
Phenazopyridine (Urogesic) PO 100-200mg TDS (provides topical analgesic effect on mucosa; not to be taken in G6PD patients, S/E includes N/V, orange-red discolouration of urine and stool)
and/or
urinary alkalization (relives mild discomfort, but unproven benefit)
For microbiological clearance, when is repeat urine culture needed for patients with UTI?
In pregnant women to document clearance of infection, and in those who did not respond clinically to abx regimen
Describe the general lifestyle modifications for prevention of UTI?
Drink lots of fluid to flush out bacteria in the urinary tract (6-8 glasses a day)
urinate frequently whenever you feel the urge
urinate shortly after sex
for women, always wipe from front to back after using the toilet, esp. after a bowel movement
keep the urethral area dry by wearing cotton underwear and loose-fitting clothes that are more airy; avoid tight jeans and nylon underwear which can trap moister
for women, avoid diaphragm or spermicides as contraception
Describe the methods for prevention of CA-UTI?
avoid unecessary catheter use (always review the need for cattheter)
minimize duration of catheter use
long-term indwelling catheters should be changed before blockage is likely to occur
use of closed system
ensure aseptic insertion technique
List the possible supplementary agents that may have benefits in preventing UTI? (remains controversial, need more reliable evidence)
cranberry juice, intravaginal estrogen cream, lactobacillus probiotics
Define nosocomial/healthcare associated UTI?
Nosocomial UTI: onset of UTI >= 48h of admission
Healthcare-associated UTI: patients who have UTI who have recent hospitalization in the past 6 months, recent antibiotic use in the past 6 months, recent invasive urologic procedure in the past 6 months, who has an indwelling catheter
Define catheter-associated UTI (CA-UTI)
CA-UTI: the presence of signs and symptoms compatible with UTI with no other identified sources of infection, along with siginificant isolates (>10 cfu/mm^3) of >=1 bacterial species, in a single catheter urine specimen, in patients who have an indwelling urethral, indwelling suprapubic, intermittent catheter OR in a midstream voided urine specimen from a patient whose catheter was removed in the last 48h
For catheter-associated UTI, short term catheterisation (<7 days) is associated with single organism infection while long term catheterisation is associated with polymicrobial infection
Name the specific risk factors for the development of CA-UTI
duration of catheterization, colonization of the drainage bag/periurethral area/catheter, poor quality of catheter care incl. insertion, female, DM, impaired renal function
Describe the empiric therapy for community-acquired cystitis in women (uncomplicated, complicated) and men
uncomplicated cystitis in women:
first line:
co-trimoxazole PO 800/160mg BD x 3 days
nitrofurantoin PO 50mg QDS x 5 days
fosfomycin PO 3g as a single dose
other alternatives:
cephalexin 250-500mg QDS x 5-7 days
amoxicillin-clavulanate 625mg BD x 5-7 days
ciprofloxacin 250mg BD x 3 days
levofloxacin 250mg OD x 3 days
complicated cystitis in women:
as above, but treat for 7-14 days; fosfomycin 3g EOD x 3 doses
cystitis in men:
as above, but treat for 7-14 days; fosfomycin is not used
Describe the empiric therapy for community-acquired pyelonephritis in women and men
pyelonephritis in women:
first line:
co-trimoxazole PO 800/160mg BD x 10-14 days
other alternatives:
cephalexin PO 500mg QDS x 10-14 days
amoxicillin-clavulanate PO 625mg TDS x 10-14 days
ciprofloxacin PO 500mg BD x 7 days
levofloxacin PO 750mg OD x 5 days
if patient is severe and need IV:
cefazolin IV 1g q8h
amoxicillin-clavulanate IV 1.2g q8h
ciprofloxacin IV 400mg q12h
and/or gentamicin IV/IM 15mg/kg/day or as a single dose
pyelonephritis in men:
as above, prefer to use co-trimoxazole and ciprofloxacin for PO; treat for 6 weeks if prostatitis is present
Describe the empiric therapy for nosocomial/healthcare acquired UTI
for less sick patients:
Ciprofloxacin PO 500mg BD x 7-14 days
Levofloxacin PO 750mg OD x 7-14 days
for more sick patients:
Cefepime IV 2g q12h x 7-14 days +/- amikacin IV 15mg/kg/day or as a single dose x 7-14 days
Meropenem IV 1g q8h x 7-14 days
Imipenem-cilastin IV 500mg q6h x 7-14 days
Describe the empiric therapy for CA-UTI
for less sick patients:
Levofloxacin PO 750mg OD x 7-14 days
for more sick patients:
Cefepime IV 2g q12h x 7-14 days +/- amikacin IV 15mg/kg/day or as a single dose x 7-14 days
Meropenem IV 1g q8h x 7-14 days
Imipenem-cilastin IV 500mg q6h x 7-14 days
*for women =< 65 years old and have CA-UTI cystitis (no signs and symptoms of pyelonephritis) after an indwelling catheter has been removed in the past 48h, to treat as an uncomplicated community-acquired cystitis, hence give co-trimoxazole PO 800/160mg BD x 3 days
Describe the options for culture-directed treatment of community-acquired ASB/cystitis/pyelonephritis and nosocomial/healthcare associated UTI in pregnant women
First line: beta-lactams
ASB/cystitis:
Cephalexin PO 250-500mg QDS
Amoxicillin-clavulanate PO 625mg BD
Treat for 4 days if ASB and 7 days if cystitis
pyelonephritis:
Cephalexin PO 500mg QDS x 14 days
Amoxicillin-clavulanate PO 625mg TDS x 14 days
Cefazolin IV 1g q8h x 14 days
Amoxicillin-clavulanate IV 1.2g q8h x 14 days
nosocomial/healthcare associated UTI:
Cefepime IV 2g q12h x 7-14 days
Meropenem IV 1g q8h x 7-14 days
Imipenem-cilastin IV 500mg q6h x 7-14 days
