IID 16 and 17: UTI Flashcards
What are the common organisms of community-acquired UTIs? (5)
- Escherichia coli (50%)*
- Klebsiella pneumoniae (4%)*
- Proteus mirabilis (3%)
- Staphylococcus saprophyticus
- Enterococcus faecalis (2.5%)
** = resistant organisms becoming more prevalent
What are the common organisms of hospital-acquired UTIs? (7)
- Escherichia coli*
- Pseudomonas aeruginosa
- Proteus sp.
- Enterobacter sp.
- Serratia sp.
- Enterococcus sp.
- MRSA/MSSA
- = resistant organisms becoming more prevalent
What are the risk factors for drug resistant pathogens?
recent (in last 3-6 months):
- broad-spectrum antibiotic use (ie. 3rd gen or greater cephalosporin, FQ, or TMP/SMX use)
- healthcare exposure (hospital, LTCF)
- travel to parts of the world where prevalence of MDR gram-negatives is high
- prior resistant urinary isolate
What are the predisposing factors for UTIs? (7)
(from highest to lowest)
- age (adult) and gender
- age (children) and gender
- vesico-ureteral reflux
- obstruction
- post-void residual
- men
- comorbidities
What are some of the values of macroscopic urinalysis for UTI diagnosis?
- pH: > 4.5-8.5
- protein: +
- glucose: –
- nitrite: + if gram-negative
- leukocyte: + if pyuria
What are some of the values of microscopic urinalysis for UTI diagnosis?
- WBC: > 5/hpf (or > 10/mm^3)
- casts: + if pyelonephritis
- epithelial cells: < 25 cells/hpf
- bacteria: +
What are the significant counts for UTI diagnosis?
- ≥ 3 mixed organisms – probable contaminant
- symptoms AND ≥ 10^5-10^8 cfu/L
When is a referral for a urine culture considered?
- suspected pyelonephritis
- hospitalized
- pregnant
- male
- child
- failed appropriate empiric therapy
- recurrence within 1 month of previous treatment
- complicated UTI
- uncertainty about diagnosis
When should a patient be referred to their primary care provider for UTI?
- age < 16
- living in long-term care
- pregnant or breastfeeding
- no previous diagnosis of cystitis
- previous UTI within 1 month – may be a relapse
- recurrence (≥ uncomplicated UTIs in 6 months or ≥ uncomplicated UTIs in 12 months) AND taking medication associated with increased risk of UTI OR interested in prophylactic therapy
- atypical signs and symptoms
- at risk of complicated UTI
- taking medication associated with cystitis
- unable to use first, second, or third-line options due to allergies/intolerances
- unable to confirm self-diagnosis
When is asymptomatic bacteriuria treated? (4)
- neonates and preschool children
- pregnant women
- before surgery requiring removal of prosthetic material
- prior to gyneo/urological related surgery
How are male UTIs treated?
as pyelonephritis
What is a relapse?
same organism, occurs within 2 weeks of initial treatment, organisms may be buried in deep tissue (ie. kidney)
What is a reinfection?
different strain or species (90% of cases), organisms reintroduced from fecal reservoir
- 3 UTIs/year
What is one method of prophylaxis/prevention for postmenopausal women with recurrent UTIs not used in premenopausal women?
topical vaginal estrogen therapy
What is the treatment for symptomatic catheter-associated UTI?
- symptoms AND single catheter urine culture with ≥ 10^5 to ≥ 10^8 cfu/L of 1 to 2 organisms
- change catheter and treat as pyelonephritis
What are the risk factors for pediatric UTIs? (6)
- sex – age < 6 months (male > female), age beyond 6 months (female > male)
- uncircumcised
- severe constipation
- neurogenic bladder dysfunction
- anatomic abnormality – vesicoureteral reflux, posterior urethral valves
- spinal cord abnormality
List the methods of pediatric urine collection from least to most contamination.
suprapubic aspiration/needle (< 2%) < transurethral bladder catheter (< 10%) < clean catch (8-24%) < urine bag (up to 63%)
What are some of the values of macroscopic urinalysis for pediatric UTI?
- pH: 5.0
- *nitrite: +
- glucose: –
- urobilinogen: –
- hemoglobin: trace
- *leukocyte esterase: +
- protein: –
- ketones: large
- bilirubin: –
- specific gravity: 1.030
What are some of the values of microscopic urinalysis for pediatric UTI?
- leukocytes: 10-20
- erythrocytes: 3-10
- other elements: mucous
- specimen volume: 3 mL
Why isn’t nitrofurantoin used for pediatric UTIs?
often assume infection in child is pyelonephritis, and nitrofurantoin cannot reliably treat pyelonephritis because it does not achieve high enough therapeutic serum concentrations in kidney
- also risk of hemolytic anemia in neonates
- used for cystitis only
What condition is ciprofloxacin associated with in pediatrics?
arthropathies
- articular cartilage damage
- arthralgias may occur more frequently with fluoroquinolones than other antibiotics
- note: cipro is not contraindicated in children – just not first-line choice
What condition is TMP/SMX associated with in pediatrics?
kernicterus/hyperbilirubinemia
- sulfonamides displace bilirubin from albumin
- higher bilirubin can cause irreversible brain damage
What condition is ceftriaxone associated with in pediatrics?
kernicterus/hyperbilirubinemia
How is a culture and susceptibility report used?
- if resistant organism: change antibiotic
- if susceptible organism: continue same antibiotic or change to narrow-spectrum antibiotic based on report
When is renal and bladder ultrasonography (RBUS) used?
2-24 months with first febrile UTI
When is voiding cystourethrogram (VCUG) used?
if RBUS reveals hydronephrosis, scarring, or other findings
- infants with recurrent UTI
- can diagnose vesicoureteral reflux
Is antibiotic prophylaxis for UTI recommended for children?
- may or may not reduce the risk of symptomatic UTI
- not shown to prevent complications of UTI (ie. renal scarring)
- not routinely recommended
