UTIs Flashcards
Urinary Tract Infections epidemiology
● 8.2 million office visits annually
● 1.7 million emergency department visits annually
● $ 6 billion health care expenditures annually
● Present may differ depending on location of infection
○ Cystitis most common
● Hx/presentation, UA dip, UA micro, and/or culture
are typically sufficient to make the Dx
● 60% of women will report UTI in their lifetime
UTIs Etiology – 3 possible ways for bacteria to enter the urinary tract
● Bacteria ascension
○ Regarded as most common cause
○ Primary cause of pyelonephritis (ascension from bladder Mto the kidney)
● Direct extension of bacteria from an adjacent organ
○ Abscess or fistulas
● Hematogenous spread
○ Spread through the blood in immunocompromised
Most common presentation of UTIs
Cystitis
Causative organisms of UTIs
○ E. coli (86%)
○ Staph saprophyticus (4%)
○ Klebsiella species (3%)
○ Proteus species (3%)
○ Enterobacter species (1.4%)
○ <1% – Citrobacter species,
Enterococcus species, Pseudomonas,
Klebsiella, Proteus, Candida, viruses,
Gonorrhea, Chlamydia, etc.
Etiology – Risk Factors by Demographic
● Neonates: Uncircumcised – 85% higher incidence than uncircumcised
● Children: Bowel and bladder dysfunction, vesicoureteral reflux, prior UTI
● 16-35 years old: Intercourse (also us of diaphragm or spermicide)
● 35+ years old Obstruction, GU surgery, bladder prolapse, ureterocele, neurogenic bladder, bowel and bladder dysfunction
Etiology – Other Risk Factors of UTIs
● Post Menopausal: Lack of estrogen – tissue integrity and pH
● Obesity
● Diabetes
● Sickle cell trait
● Pregnancy
● Poor hygiene: Towelettes/wipes
● Frequent sitting
● Bubble baths
● Catheters
● Age
Urinary Tract Infections Host defense
● Estrogen: Encouraged health tissues, and stimulates lactobacillus (keeps pH down
→ decrease colonization of other uropathogens)
● Low pH of urinary tract
○ Urea
○ Lactobacillus
● Epithelial lining
○ Quick recognition of bacteria
○ Antibody production (kidneys) → decrease bacterial adherence and
cause phagocytosis
○ Cytotoxic cells secrete Mannose → bacteria (e.coli) can’t adhere to
the bladder wall as easily
● Complete void: The overlapping layers in the detrusor muscle allow for complete void
● Frequent voiding: Sensation of urgency when the bladder is full or irritated…an effort
to push out irritant
If lower tract protections to UTI fail →
bacteria can ascend the urinary tract
○ Additional host defenses will
activate leukocyte phagocytosis and
antibodies produced in the kidney
○ Inflammation and infection ensues
Coinfection of UTIs with _____ and chlamydia was demonstrated in 20% of males and 42 % of females
gonorrhea
Urethritis - Etiology
Sexually Transmitted Infection
● Gonococcal Urethritis (GU)
● Nongonococcal Urethritis (NGU)
● Recurrent/persistent Urethritis (NGU)
Urethritis Presentation/exam
● Dysuria
● Urethral pruritus
● Urethral discharge +/-
● Fever +/-
● Urinary hesitancy
○ More common with recurrent Dz
● 75% asymptomatic
Urethritis Diagnosis
● Exam
○ Urethral irritation
○ Urethral discharge +/-
● Urine amplification (NAAT PCR)
○ First void in the morning is best
○ Only accurate test for Mycoplasma
infections
● Culture of swab/discharge
Treatment of Gonococcal and/or Chlamydial Urethritis
○ Gonorrhea – Ceftriaxone 250 mg IM; single dose (99% cure rate)
○ Chlamydia – Azithromycin 1 gm; single dose
Treatment of Nongonococcal Urethritis (NGU)
○ Azithromycin 1 gm; single dose
or
○ Doxycycline 100 mg PO BID x 7 days
Treatment of Recurrent/persistent Urethritis (NGU)
If already treated with Azithromycin 1 gm single dose →
Moxifloxacin 400 mg QD x 7 days
Who else needs to be treated for urethritis
● Partner(s) must be treated
○ Partners within the last 6 months;
unless known negative test
Urethritis complications
● Males
○ Urethral strictures → infertility
● Females
○ Cervicitis → Pelvic inflammatory disease
Urethritis prevention
● Treat for both G&C
● Educated on safe-sex practices – avoiding high risk behaviors
● Routine STI screening with changing partners
● Check screening recommendation for pregnant females
Cystitis epidemiology
● Most common bacterial infection in women
● 60% of women will report UTI in their lifetime
○ 11% report 1 infection annually
○ 50% don’t seek medical attention
Cystitis Etiology
● Women > Men
○ Shorter urethra
● Ascending infection from periurethral,
vaginal or fecal flora
○ E. coli (86%), Staph, Klebsiella
● Post coital UTI
Uncomplicated Cystitis
An urinary tract infection in a healthy, non-pregnant, pre-menopausal
female patient with anatomically and functionally normal urinary tract
Complicated Cystitis
● Urinary tract that has metabolic, functional, or structural abnormalities
○ Factors that increase the risk of bacterial colonization and/or decrease the efficacy of therapy
● May involve upper and lower urinary tract
Cystitis Presentation
● Irritative voiding symptoms
○ Urgency
○ Frequency
○ Dysuria
● Suprapubic pain
● Incomplete voiding
● Urinary hesitancy
● Gross hematuria
● Incontinence
● Low back pain
● Afebrile
Cystitis exam
● Suprapubic tenderness
(seen 10-20% of cases)
● Males – DRE +/-
● Exam often unremarkable
Cystitis Diagnosis
● History and physical
○ New onset of frequency and dysuria (with absence of vaginal discharge) has a PPV for UTI of 90%
○ CBC, BMP, A1c?
● UA: Clean, midstream catch
○ RBC and Leuks means inflammation not infection
● Urine Culture: Always culture complicated UTIs
Cystitis imaging
● Imaging – (only done for complicated cystitis)
○ Renal bladder U/S with pre & post void residual
○ Voiding cystourethrogram – children, or post GU/pelvic surgery
○ CT urogram – pyelonephritis, recurrent infections, or anatomic
abnormalities suspected
● Cystoscopy
Uncomplicated Cystitis Treatment
● Healthy, non-pregnant, pre-menopausal female patient, with normal urinary tract anatomy (AUA 2020 Guidelines)
● Start empiric therapy
- Nitrofurantion
- Bactrim
- Fosfomycin
● Urine Culture +/-
Treatment of Complicated Cystitis
● Anything not “uncomplicated cystitis”
● Start empiric therapy
- Ciprofloxacin
- Levofloxacin
- Bactrim
- Augmentin
● All complicated UTIs need Urine Culture
Special Considerations for Recurrent Cystitis/UTI
● Persistence infection or reinfection with another organism
● Possible causes
○ Obstruction (BPH, stone, stricture, etc),
ureteral reflux, fistula, intercourse/hygiene,
cystitis cystica
Evaluation of Recurrent Cystitis/UTIs
● Urine cultures
● Renal bladder U/S (post void residual), VCUG, IVP
● Cystoscopy
Treatment of Recurrent Cystitis/UTI
● Surgically – correct obstruction, reflux, or repair fistula
● Hygiene
○ Proper wiping
○ Empty bladder post intercourse
● Hydrate
● Prophylactic antibiotics
○ Continuous low dose TMP or Nitrofurantoin (QD x 3-6 months)
Cystitis - special considerations with pregnancy
● Compression of the UT increases the risk of UTI
● Asymptomatic bacteriuria seen in 5-10% of
pregnancies
Cystitis- Special Considerations for HIV patients
● When CD4 count falls <200 mm-3 there is an
increased risk for bacterial and fungal UTIs
(candida and aspergillus)
● TMP-SMZ is often used to prevent
Pneumocystis Pneumonia – incidence of
UTI in these patients is quite low
Cystitis - Special Considerations for T2D
● UTIs are more common, more resistance, and more severe
● 2-5 fold increase in pyelonephritis
● The higher the A1c, the higher the risk of UTI
● Treat with abx pending C&S results
○ Often Fluoroquinolones work well
○ Avoid TMP-SMZ – can cause hypoglycemia
Cystitis - Special Considerations for Catheterized Patients
● Cultures will alway be positive, but often not symptomatic
○ Biofilms form within 72 hours of placement
● Do not treat asymptomatic bacteriuria in patients with indwelling
catheters
● Preventive measures
○ Silicone catheter
○ Catheter/bladder “rinses” – Iodine or acetic acid solutions
○ Regular catheter changes
Cystitis complications
● Appropriate Tx should have a rapid resolution of symptoms
● Non-compliance or failure to respond to therapy
○ Drug resistance
○ Anatomic abnormality
● Pyelonephritis → sepsis → death
● Permanent renal impairment
Cystitis Prevention
● Hydration
● Ensure full emptying of the bladder – repeat voids
● Hygiene
○ Urinate after intercourse, wipe front to back, no bubble baths, etc.
● Preventative abx – post coital, intermittent self-start
● Probiotics – Lactobacillus; restore natural flora (promote host defence)
Pyelonephritis etiology
● Infection of the kidney parenchyma and renal pelvis
● Mostly caused by gram negative bacteria
● Ascending infection from the bladder up the ureters
○ Staph can spread through a hematogenous spread
Pyelonephritis Presentation
● Fever (more often than not)
● CVA tenderness (can be bilateral)
● Nausea/Vomiting
● Anorexia
● Irritative voiding (urgency,
frequency, and dysuria)
Pyelonephritis DDx
Acute cystitis or lower urinary infection, STI, kidney stones,
lumbar injury, PID, lower lobe pneumonia, pancreatitis,
appendicitis, diverticulitis
Pyelonephritis Diagnosis
● CBC – Elevated WBC
● UA – Pyuria, bacteria (gram neg rods – e. coli)
○ Urine micro – may see WBC cast
● Urine C&S
● Blood Cultures – sepsis 20-30 %
Pyelonephritis imaging
Seldom required
● Renal U/S – Looking for hydronephrosis (obstruction), abscesses
○ Ideal in the pediatric patient
● CT – Renal enlargement, inflammation, decreased renal perfusion
compressed collecting system, “perinephric fat stranding”
● MRI – Renal vascular evaluation
Pyelonephritis treatment (outpatient)
● Determine if the Pt is stable enough be treated outpatient
- Fluoroquinolones or Bactrim or Augmentin
● Adjust the treatment
according culture
results if needed
Pyelonephritis treatment (inpatient)
Antibiotics (IV)
● Ampicillin & aminoglycosides (Vanco, Gent)
● Augmentin or 3rd gen cephalosporin
● IV abx are continued for 24 hours after fever
breaks, then PO abx are given for 14 days
● Adjust the treatment according culture
Pyelonephritis Admitting Criteria
● Unable to retain fluid and/or medication
● Signs/Sx of urosepsis
● Fever >102.2F
● High WBC
● Hypotension
● Stones
● Pregnancy
Pyelonephritis Complications
● Missed pyelonephritis could lead to sepsis
Pyelonephritis prevention
● UTI prevention
