Brown: Clinical Aspects of Urinary Tract Infections Flashcards

1
Q

Significant Bacteriuria definition:

What concentration in symptomatic patients?

A

> 105 cfu/mL of urine (only needs to be 102 cfu/mL in symptomatic patients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Asymptomatic Bacteriuria:

A

Significant bacteriuria in the absence of any symptoms suggestive of UTI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cystitis (Lower UTI):

A

Infection confined to superficial bladder mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pyelonephritis:

A

Infection that involves the renal parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Uncomplicated UTI:

A

Cystits or pyelonephritis that occurs in an otherwise healthy, non-pregnant woman with no underlying structure or functional abnormality of the urinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Complicated UTI:

Full list, don’t memorize

A

Associated with any of the following

o Obstruction: of any site of the urinary tract (enlarged prostate, uterine/bladder prolapsed, stones, tumor)
o Foreign body: catheter or stent
o Incomplete voiding: detrusor muscle dysfunction (neurologic disease, medications)
o Vesicoureteral reflex: urine travels up the ureters instead of out the urethra (usually only in kids)
o Recent history of instrumentation/invasive urologic procedure
o Renal transplant recipient: always classified as complicated
o Male: always classify as potentially complicated
o Pregancy: always classified as complicated
o Diabetes
o Immunocompromise
o Health-care associated infection
o Multi-drug resistant infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Recurrence:

A

Relapse or reinfection (most often)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Relapse:

A

Recurrence due to the same microorganism (not completely eradicated; within 2 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Reinfection:

A

Recurrence due to a different microorganism (usually after 2 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How common?

A

Extremely common:

  • Second most common CA infection
  • Most common health care associated infection (CMS no longer reimburses hospitals for costs due to UTIs because they are seen as preventable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Most common source of what type of bacteremia?

What can childhood UTIs cause?

A

Can cause bacteremia: most common source of Gram negative bacteremia

Can cause chronic renal failure: early childhood UTIs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Vesicoureteral reflex and in what population is it found?

A

Vesicoureteral reflex: urine travels up the ureters instead of out the urethra (usually only in kids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Prevalence by Age Group

Infant:
1-15 years:

A

Infant: more common in males than females, although rare in general

1-15 years: more common in females (4-5%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Prevalence by Age Group

16-35 years:
36-65 years:

A

16-35 years: more common in females (increases to 20%- sexual activity)

36-65 years: more common in females, but males also increase (due to benign prostatic hypertrophy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Prevalence by Age Group

65+ years:

A

65+ years: still more common in females, but very high rates in both genders (again, mainly due to BPH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Natural History of UTI

In Pregnancies:
Resolve without treatment?

A

Asymptomatic bacteriuria occurs in some pregnancies and many of those will develop pyelonephritis during pregnancy if untreated

Symptomatic and asymptomatic UTIs will resolve without treatment, but antimicrobial therapy increases probability of cure and speeds symptom resolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Bacteria originating in intestine normally colonize:

A

Bacteria originating in intestine normally colonize vaginal introitus, periurethra and distal urethral meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are uropathogenic E.coli members of?

Where do they typically reside?

How does UPEC compare to commensal E.coli?

A

exPEC group

Reside in the gut without consequences. Can disseminate to/colonize extra-intestinal sites

Compared to commensal E.coli UPEC are more likely to harbor genes linked to virulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Infection occurs by ascending route

Effect on men vs women:
What facilitates entry of organisms into the bladder?

A

This is why it is more common in women (shorter urethra); in addition, prostatic antibacterial secretions may also contribute to decreased incidence in men

Sexual intercourse facilitates entry of organisms into the bladder (dose-response relationship between frequency of intercourse and risk of UTI in young women)

20
Q

Host Defenses

What are defensive urine characteristics?
Inhibitors of bacterial adherence:
Role of humoral immunity:

A
Urine characteristics (high osmolality, low pH, presence of organic acids)
- Flushing out of bladder urine during voiding 

Inhibitors of bacterial adherence to uroepithelial cells (Tamm-Horsfall protein, bladder MPS, sIgA)

Role of humoral immunity poorly understood

21
Q

What are Tamm-Horsfall protein, bladder MPS, sIgA?

A

Inhibitors of bacterial adherence to uroepithelial cells

22
Q

What can happen once the bacteria is established in the bladder?

A

Once established in bladder, can ascend to kidney: kidney can also be infected via hematogenous route (rare)

23
Q

Cystitis
Clinical Presentation

Mild infection:

A

Mild infection:
o Dysuria, urgency, frequency, possible hematuria
o Suprapubic or low back pain
o NO signs of systemic infection (fever, chills etc.)

24
Q

Cystitis
Clinical Presentation

Physical Exam:
Differential:

A

Physical Exam: suprapubic tenderness

Differential: perhaps vaginitis or urethrisis, but the urgency and frequency are pretty characteristic of cystitis

25
Q

Pyelonephritis
Clinical Presentation
Symptoms

Symptoms of cystitis present?
Pain/tenderness where?
Signs of systemic toxicity present:

A

Symptoms of cystitis may or may not be present

May have flank pain/tenderness

Signs of systemic toxicity present: fevers, chills, N/V/D, hypotension

26
Q

Pyelonephritis
Clinical Presentation

Physical Exam:

A

Fever and costovertebral angle tenderness

27
Q

Pyelonephritis
Clinical Presentation

Presentation in the elderly:
May present as: (3)

A

Presentation in the elderly is a diagnosis of exclusion: presence of bacteriuria high in elderly to begin with; need to thoroughly asses and may present as one of the following:
o Unexplained fever
o New onset incontinence
o Change in mental status

28
Q

UTIs in Pediatric Population
Infants

Presentation: (4)

A
Non-specific presentation
o	Poor feeding 
o	Failure to gain weight
o	GI symptoms
o	Unexplained fever (including febrile seizures)
29
Q

UTIs in Pediatric Population
Toddlers/Preschoolers

Presentation: (3)

A

o Lower tract symptoms
o Recurrence of daytime/nocturnal enuresis
o Fever

30
Q

UTIs in Pediatric Population

School-Aged:

A

Same as adults

31
Q

EVALUATION

What type of “catch” urine specimen is requried?
Method for infants and toddlers:
What may be used?

A

Urine specimen required:

  • Midstream “clean catch”
  • Stick on bags for infants and toddlers
  • Catheterization may be used to obtain specimen
32
Q

EVALUATION
Dipstick detects:
What is pyuria?

A

Dipstick: to detect presence of RBCs, WBCs and bacteria

WBCs in urine (pyuria) is supportive of UTI

33
Q

Patients with Pyuria
Spin Specimen

What WBC count is considered significant?

A

Spin Specimen: 5-10 leukocytes per high-power field considered significant

34
Q

Before Knowing Presence of Pyruria

What is considered significant? What does it represent?
Gram stain is an easy way to detect:

A

Gram Stain of Unspun Specimen: 1 or more bacteria per high-power field considered significant

  • Represents growth of greater than 105 cfu/mL in urine culture
  • Easy way to detect pyuria, bacteriuria and morphology of infecting agent all at once
35
Q

Managing Uncomplicated Cystitis

How do you treat a healthy, non-pregnant woman who presents with classic signs of cystitis?

Urine culture:
Use what to confirm diagnosis?

A

Treat empirically: healthy, non-pregnant woman who presents with classic signs of cystitis

Culture of urine is not recommended: results would not be available in clinically meaningful time frame

  • Microbiology is predictable
  • May use urine dipstick to confirm diagnostic impression
36
Q

What requires a urine culture?

A

Patients with complicated cystitis and pyelonephritis

37
Q

Differentiating Lower UTIs (Cystitis) from Upper UTIs (Pyelonephritis)

Usually based on what grounds?
~30% of women with symptoms of cystitis may have:

A

Usually based on clinical grounds:

Issue is that ~30% of women with symptoms of cystitis may have subclinical pyelonephritis

38
Q

Differentiating Lower UTIs (Cystitis) from Upper UTIs (Pyelonephritis)

What do laboratory tests attempt to do?

What are WBC casts specific for?
Sensitivity:

A

Laboratory tests attempt to localize infection more accurately

WBC Casts: specific for pyelonephritis (ie. if present, its pyelonephritis) but not sensitive because they are not present in all cases of pyelonephritis

39
Q

Smell and appearance of urine:

A

Smell and appearance of urine is not evidence of a UTI: rather, evidence of hydration and recent dietary intake

40
Q

Microbiology

Cystitis:

A

E.coli: 80%
S.saprophyticus: 10-20%
Rarely: Proteus, Klebsiella, Enterococcus

41
Q

Microbiology

Pyelonephritis:

A

E.coli: Mainly

Rarely: Proteus, Klebsiella, Enterococcus

42
Q

Microbiology

Complicated Infections and Healthy Care-Associated UTIs

A

E.coli: still an important cause

Others: Proteus, Klebsiella, Enterobacter, Serratia, Citrobacter, Pseudomonas, Enterococcus

43
Q

Microbiology

Pediatric Population:

A

E.coli: mainly
Klebsiella, Proteus
Rarely: coagulase-negative staph (epidermidis, albus)

44
Q

When do you treat asymptomatic bacteriuria?

A

Asymptomatic Bacteriuria: only treated in certain circumstances

  • Pregnancy
  • Prior to invasive instrumentation of urinary tract or urologic surgery
  • Renal transplant patient (during first 6 months post-transplant)
45
Q

Who is imaging reserved for? (3)

A

Reserved for only some patients:

  • Complicated infections
  • Recurrent pyelonephritis
  • Pyelonephritis that does not respond to appropriate antibiotic therapy (in 72-96 hours)
46
Q

What disease is looked for in children?

What imaging is used?

A

CAT scans, ultrasounds, and specialized procedures in children looking for vesicoureteral reflux