UTI Flashcards
What is Asymptomatic Bacteriuria(ASB)?
isolation of significant colony counts of bacteria in the urine(bacteriuria) from a person WITHOUT symptoms of UTI
Screening and treatment of ASB is only indicated for ______ populations
1) Pregnant women [2-7%]
2) Patients going for urological procedure in which mucosal trauma/bleeding is expected [eg. TURP, cystoscopy with biopsy]
When and Why do pregnant women screen and treat ASB?
To prevent pyelonephritis, preterm labor and infant low birth weight
Screen at one of the first visits(12-16 weeks gestation)
- Do urine culture
- If bacteriuria, treat with active antibiotics(based on AST) for 4-7 days
When and Why do screen and treat ASB?
To prevent postoperative bacteremia and urosepsis
Screen prior to procedure — 2-3 days before
- If bacteriuria, use active antibiotics as surgical antibiotic prophylaxis(SAP)(based on AST)
Does not include placement of a urinary catheter
Epidemiology of UTI
Increasing from young to old
* 0-6 mths: males > females
* 1-adult: females > males
* Elderly(age>65): equal
What are the 2 routes of infection of UTI
- Ascending [most common]
* colonic/fecal flora colonise periurethral area/urethra → ascend to bladder & kidney
* Gram-negative bacilli (E.coli/Klebsiella/Proteus) - Hematogenous(descending)
* Organism at distant primary site(heart/bone) → bloodstream(bacteremia) → urinary tract → UTI
* S.aureus, TB
What are the factors determining the development of UTI?
1) Competency of the natural host defense mechanisms
- bacteria stimulate micturition(increase urge of emptying bladder)
- antibacterial properties of urine and prostate secretions
- anti-adherence mechanism of bladder(prevent bacteria attachment)
- Inflammatory response by leukocytes → phagocytosis
2) Size of the inoculums(load of bacteria that is present at the site of infection)
3) Virulence/pathogenicity of the microorganism
What are the risk factors of UTI?
- Gender(Female > male)
- Sexual intercourse
- Abnormalities of the urinary tract (prostatic hypertrophy, kidney stones, urethral strictures, vesicoureteral reflux)
- Neurological dysfunctions (stroke, DM, spinal cord injuries)
- Anticholinergic drugs (SE: urinary retention)
- Catheterization and other mechanical instrumentation
- Diabetes
- Pregnancy
- Use of diaphragms & spermicides
- Genetic association(positive family history)
- Previous UTI
NPM of UTI
1) Drink lots of fluid to flush bacteria
2) Urinate frequently
3) Urinate shortly after sex
4) Wipe from front to back
5) Wear cotton underwear and loose-fitting clothes so that air can keep the area dry
6) Those on diaphragm/spermicide as birth control: consider modifying your birth control method
* Unlubricated condoms or spermicidal condoms increase irritation(grow bacteria)
What are considered complicated UTI?
- UTI in men, children and pregnant women
- Presence of complicating factors:
1) Functional/structural abnormalities or urinary tract
2) genitourinary instrumentation
3) DM
4) immunocompromised host
Symptoms of cystitis(LUTI)
- Dysuria(pain on urination)
- Urgency
- Frequency
- Nocturia
- Suprapubic heaviness or pain
- Gross hematuria
Symptoms of pyelonephritis(UUTI)
- Fever, malaise
- Rigors
- Headache
- Nausea and vomiting
- Flank pain
- Costovertebral tenderness(renal punch)
- Abdominal pain
Microscopic urinalysis(UFEME: urine formed elements and microscopic examination) tests for?
White blood cells(WBC)
* >10 WBCs/mm3 = pyuria
* Signifies presence of inflammation(may or may not be due to infection. If symptomatic, pyuria correlates with significant bacteriuria
* Absence of pyuria = unlikely UTI
Red blood cells(RBC)
* Presence(microscopic >5/HPF or gross) = hematuria
* Frequently occurs in UTI but non-specific
Microorganisms
* Identify bacteria or yeast using gram-stain
WBC casts
* Masses of cells and proteins that form in renal tubules(kidneys)
* Indicates upper tract infection/disease
if there is presence of squamous epithelial, urine might have been contaminated
What are the 2 Chemical urinalysis(dipstick) tests?
What do they test for?
1. Nitrate
- Positive test detects presence of gram-negative bacteria
- Only gram negative bacteria reduces nitrate to nitrite
- Requires at least 10^5 bacteria/ml
- False-negative results due to presence of gram-positive organisms and P.aeruginosa, low urinary pH, frequent voiding and dilute urine
2. Leukocyte esterase(LE)
- Positive tests detects esterase activity of leukocytes in urine
- Correlates with significant pyuria(>10 WBCs/mm3)
When is urine culture(pre-treatment culture) required?
- Pregnant women
- Recurrent UTI(relapse within 2 weeks or frequent)
- Pyelonephritis
- Catheter-associated UTI
- All men with UTI
Not need for urine culture in uncomplicated cystitis
What are the likely pathogens for uncomplicated/community-acquired UTI?
- Escherichia coli(>85%)
- Staphylococcus saprophyticus(5-15%)
- Enterococcus faecalis
- Klebsiella pneumoniae
- Proteus spp
What are the likely pathogens for complicated/healthcare-associated UTI?
- Escherichia coli(~50%)
- Enterococci
- Proteus spp
- Klebsiella spp
- Enterobacter spp
- P.aeruginosa
HA risk factors: recent/frequent exposure to healthcare settings
(last 90 days, current>/=2days, nursing home)
____ commonly causes UTI from bacteremia
____ causes UTI by acting as a possible contaminant
S.aureus
Yeast/Candida
When do you treat UTI positive culture with antibiotics?
NO if ____
YES if ____
- NO if patient does not have symptoms of UTI but positive culture(ASB) except for Pregnant women & patients going for urologic procedure in which mucosal trauma/bleeding is expected
- YES if patients is symptomatic(urinary symptoms) or any of the 2 exceptions above
What are the first line empiric abx for cystitis in women?
- PO Co-trimoxazole 800/160 mg bid x 3d (2 tablets)
- PO Nitrofurantoin 50mg qid x 5d
- PO Fosfomycin 3g single dose
Alternatives:
- PO beta-lactams x 5-7 days
- PO cefuroxime 250 mg bid
- PO amoxicillin-clavulanate 635 mg bid
- PO cephalexin 250-500mg qid(rising resistance)
- PO fluroquinolones x 3 days
- PO ciprofloxacin 250 mg bid
- PO levofloxacin 250 ng daily
Collateral damage is high, ONLY oral for pseudo
What are the first line empiric abx for Complicated Cystitis in women?
- Same as uncomplicated cytitis in women BUT
- Treat for longer duration (7-14 days)
- Fosfomycin PO 3g EOD x 3 doses
What are the first line empiric abx for Community-acquired pyelonephritis(kidney) in women?
- PO fluoroquinolones
- PO ciprofloxacin 500mg twice daily x 7 days
- PO levofloxacin 750mg daily x 5 days
What are the 2nd and 3rd line empiric abx for Community-acquired pyelonephritis(kidney) in women?
2nd line: PO co-trimoxazole 160/800mg twice daily x 10-14 days
3rd line: PO beta-lactam x 10-14 days
- PO cefuroxime 250-500 mg bid
- PO amoxicillin-clavulanate 625mg tds
- PO cephalexin 500mg qid
What are the empiric abxs for Community-acquired pyelonephritis(kidney) in women?
that are severely ill;require hospitalization[AG not good if bacteremia]
OR
unable to take oral drugs
- Initial intravenous(IV) therapy
- IV ciprofloxacin 400mg bid
- IV cefazolin 1g q8h
- IV amoxi-clav 1.2g q8h
**AND/OR ** - IV/IM gentamicin 5mg/kg
- To cover low % of ESBL ecoli/klebsiella in the community
Switch to oral when patient improved or able to take orally
- Initial empiric therapy should be modified when result of urine culture and susceptibility becomes available(->definitive/culture-directed therapy)
What are the first line empiric abx for Community-acquired UTI in men?
More specifically:
1. For cystitis, NO concern for prostatitis
2. For cystitis + concern for prostatitis/pyelonephritis
- Same as women
- Treat for longer duration (7-14 days)
- Fosfomycin PO 3g EOD x 3 doses
- PO ciprofloxacin 500mg twice daily
- PO co-trimoxazole 160-800mg twice daily
- Treat for 10-14 days, will need longer duration if prostatitis is confirmed(6 weeks)
- PO ciprofloxacin 500mg twice daily
What defines Nosocomial/Healthcare-associated
- Nosocomial - onset of UTI >48hr post admission
- **Healthcare associated **- patients who have been hospitalized or underwent invasive urological procedures in the last 6 months, has an indwelling urine catheter
What are the empiric abx for Nosocomial/Healthcare-associated pyelonephritis?
Possibility of Pseudomonas aeruginosa
and other resistant bacteria:
- Broad spectrum B-lactam may be used
- IV cefepime 2 g q12h +/- IV amikacin/gentamicin 15mg/kg/d
- IV imipenem 500mg q6h
- IV meropenem 1g q8h
duration of treatment: 7-14 days
Less sick patients(oral therapy)
- PO levofloxacin 750mg
- PO ciprofloxacin 500mg bid
duration of treatment: 7-14 days
What is Catheter-associated UTI
- most common cause of nosocomial UTI
- Presence of symptoms or signs compatible with UTI with no other identified source of infection along with 10^3 cfu/mL of >/= 1 bacterial species in a single catheter urine specimen in patients with indwelling urethral, indwelling suprapubic, or intermittent catheterization or in a midstream voided urine specimen from a patient whose catheter has been removed within the previous 48 hours
What are the risk factors for Catheter-associated UTI
- Duration of catheterization
- Colonization of drainage bag, catheter and periurethral segment
- DM
- Female
- Renal function impairment
- Poor quality of catheter care, including insertion
How do you manage Catheter-associated UTI?
- Consider removal of catheter
- Abx only for symptomatic infection
- If stable and fever is low grade, observation rather than immediate Abx therapy
- Urine(+/- blood) culture must be taken before antibiotics is given
Abx treatment for Catheter-associated UTI
Abx:
- IV imipenem 500mg q6h
- IV meropenem 1g q8h
- IV cefepime 2g q12h +/- IV amikacin 15mg/kg(1 dose)
- PO/IV levofloxacin 750mg x 5d (for mild CA-UTI)
- PO co-trimoxazole 960mg bid x 3d
- for women = 65 years with CA-UTI without upper urinary tract symptoms after an indwelling catheter has been removed
Duration:
- Prompt resolution of symptoms: 7 days
- Delayed responses: 10-14 days
- Chronic suppressive therapy is not recommended
- Do not give prophylaxis long term, only give if patient has deadly infection
Prevention of Catheter-associated UTI
- Avoid unnecessary catheter use
- Use for minimal duration
- Long-term indwelling catheters changed before blockage is likely to occur
- Use of closed system
- Ensure aseptic insertion technique
- Topical antiseptic or antibiotics not recommended
- Prophylactic antibiotics and antiseptic not recommended
- Chronic suppressive antibiotics is not recommended
What Abx to avoid for UTI tx in pregnant women?
- Avoid ciprofloxacin
- Avoid co-trimoxazole in 1st and 3rd trimester
- Nitrofurantoin avoided at term(38-42 weeks)
- Aminoglycosides are used with caution
Treatment of UTI in pregnant women
- Beta-lactams are safe options in pregnancy(1st line in pregnant UTI)
- Treat for 4-7 days for ASB/cystitis
- Treat for 14 days for pyelonephritis
Adjunctive therapy for UTI
- Pain and fever - Paracetamol, NSAIDs
- Vomiting - Rehydration
- Urinary symptoms - Phenazopyridine(Urogesic®), Urine alkalization
100-200mg tds, Do not use if G6PD
N/V,orange-red discoloration of urine
What to monitor for UTI?
- Resolution of signs & symptoms
- Improvement or resolution by 24 to 72 hrs after initiation of effective antibiotics
- If pt fails to respond clinically within 2-3 days or has persistently positive blood/urine cultures, further investigation is needed to exclude bacterial resistance, possible obstruction, renal abscess, or some other disease process - Bacteriological clearance
- Repeat culture is not required for patients who responded - Absence of adverse drug reactions and allergies
