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Urinary Tract Infection
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Urinary Tract Infection
, UTI, Bladder Infection, Acute Cystitis
See Also
UTI in Pregnancy
UTI in Children
Urinary Tract Infection in Men
Elderly with Urinary Tract Infections
Urinary Catheter associated UTI
Recurrent UTI
Causes
Normal Host
Escherichia coli
(80-86%)
Staphylococcus
saprophyticus (10-15% of young women, 4% overall)
More aggressive and recurrent infections
Associated with
Pyelonephritis
Klebsiella
(3%)
Proteus
(3%)
Nephrolithiasis
associated infection
Proteus
(urease positive)
Klebsiella
Sexually Transmitted Disease
s
Chlamydia
Neisseria gonorrhoeae
Herpes Simplex Virus
II (
Genital Herpes
)
Risk factors
Complicated
Cyst
itis
Male gender
Pregnancy
Hospital acquired Urinary Tract Infection
Prolonged urinary tract symptoms (>1 week)
Poorly controlled
Diabetes Mellitus
Immunocompromised
Underlying urologic disorder
Vesicoureteral reflux
Recurrent complicated Urinary Tract Infections
Catheter associated Urinary Tract Infection
Neurogenic
Bladder
dysfunction
Polycystic Kidney Disease
Urologic instrumentation or stenting
Status
Renal Transplant
Urinary Tract Obstruction
(e.g.
Nephrolithiasis
)
Men with
Prostatitis
or BPH
Symptoms
Most suggestive of Urinary Tract Infection
Dysuria
(
Likelihood Ratio
2.0)
If absent,
Likelihood Ratio
0.5
Urinary Frequency
(
Likelihood Ratio
1.8)
Hematuria
(
Likelihood Ratio
1.5)
Occurs in 30% of cases
Other symptoms with Urinary Tract Infection
Urinary Urgency
Suprapubic Pain
(especially after voiding)
Differential Diagnosis
Dysuria
See
Dysuria
See
Dysuria in Children
See
Dysuria in Men
See
Dysuria in Women
Urethritis
Pain at onset of urination
Vaginitis
External
Dysuria
Vaginal irritation or discharge
Chlamydia trachomatis
Long, insidious onset
Sexually active
Acute Pyelonephritis
Fever
,
Flank Pain
, and
Nausea
or
Vomiting
Risk factors for cystitis with occult
Pyelonephritis
Women (30% have subclinical
Pyelonephritis
)
Pregnancy
Diabetes Mellitus
Immunocompromised
patients
Urinary Tract Infection under age 12 years
Genitourinary comorbid condition
Acute
Urethra
l syndrome (Sterile or low urine
Bacteria
l count)
Gonorrhea
Chlamydia
Herpes Simplex Virus
Vaginitis
Sterile Pyuria
Chlamydia
(most common)
Genitourinary Tuberculosis
(classic sterile pyuria)
Asymptomatic Bacteriuria
(organisms isolated on
Urine Culture
, but often not responsible for cystitis)
Enterococcus
Streptococcus
Agalactiae (
Group B Streptococcus
)
Hooton (2013) N Engl J Med 369(20):1883-91 [PubMed]
Labs
Urinalysis
Urine Leukocyte Esterase
(high
Test Sensitivity
but low
Test Specificity
)
Urine Nitrite
(high
Test Specificity
, but low
Test Sensitivity
)
Urine White Blood Cell
s on microscopy
Urine Culture
Not needed in uncomplicated UTI (young, healthy non-pregnant women)
Recommended in complicated UTI or suspected
Pyelonephritis
Positive for >100k organisms
Women with
Dysuria
have <100k organisms in 30% cases
Diagnosis
Factors suggestive of complicated UTI
Extremes of age (preadolescent, or post-
Menopause
)
Chronic renal disease
Diabetes Mellitus
Immunodeficiency
Pregnancy
Recent Urinary Tract Instrumentation
Ureteral Stent
s
Indwelling catheters
Urologic abnormalities
Nephrolithiasis
Neurogenic
Bladder
Polycystic Kidney Disease
Diagnosis
Prediction Rule
Criteria
New onset frequency and
Dysuria
Absent
Vaginal Discharge
and irritation
Efficacy
Pretest probability of UTI based on symptoms: 90%
Probablity of UTI with negative
Urinalysis
: 23%
Positive Predictive Value
: 90%
Interpretation
May be treated without
Urinalysis
and
Urine Culture
Editorial note: I do not recommended this (other
Dysuria
causes,
Antibiotic Overuse
)
Alternative: Even dipstick testing alone is reasonably accurate, priced and fast
Reference
Bent (2002) JAMA 287:2701-10 [PubMed]
Diagnosis
Findings suggestive of upper Urinary Tract Infection (
Pyelonephritis
)
See
Pyelonephritis
Fever
, chills
Flank Pain
Vomiting
Pregnancy (second and third trimester are higher risk)
Underlying urinary tract disorder
History of
Ureteral Stent
ing or other instrumentation
Male patients
Insulin Dependent Diabetes Mellitus
HIV Infection
Immunosuppressant
s (Chronic
Corticosteroid
use, status-post transplant)
Extremes of age (very young or very old)
Underwhelming presentations of upper tract disease
Precautions
Consider
Sexually Transmitted Infection
in
Vaginitis
or male
Dysuria
Consider
Nephrolithiasis
with Urinary Tract Infection (emergency) when
Flank Pain
is severe
Empiric antibiotic regimens should be based on local resistance rates
Urine Culture
is not needed in occasional, uncomplicated Urinary Tract Infection (young, healthy, non-pregnant women)
Assume upper tract disease in findings listed above
Adjust management strategy to treat upper tract (e.g. avoid
Macrobid
or
Nitrofurantoin
)
Management
Gene
ral
Gene
ral measures in women
Women should clean perineum wiping front to back
Women should empty
Bladder
before, after intercourse
Avoid
Contraceptive Diaphragm
Antibiotics
Course: Anticipate symptom relief within 36 hours of starting antibiotics
Antibiotic duration
Uncomplicated treatment: 3 days (except noted)
Nitrofurantoin
and
Macrobid
course is 5 days (was 7 days)
Complicated treatment: 10 day course
Antibiotic Resistance
increasing
Trimethoprim Sulfamethoxazole
(
Septra
): 18%
Beta Lactams: 20%
Ampicillin
: 38%
Nitrofurantoin
resistance low (1-2%)
Fluoroquinolone
resistance low (2.5%)
Avoid as first line agents if possible (due to other adverse effects)
Consider in areas of high
Septra
resistance areas
Cure may occur despite resistance to antibiotic used
Risks for resistance
Trimethoprim Sulfamethoxazole
within last 3-6 months
Diabetes Mellitus
Recent hospitalization
Travel outside United States
Resistance rates in community >20%
Acute Uncomplicated UTI: First-Line agents
Note that
Ciprofloxacin
has been demoted from first-line agent due to adverse effects (see below)
Trimethoprim-Sulfamethoxazole (
Bactrim
) DS one orally twice daily for 3 days
Avoid if local resistance rate >20%
Nitrofurantoin
(
Macrobid
)
Macrobid
100 mg orally twice daily for 5 days
Avoid if GFR <30 ml/min (risk of interstitial pulmonary fibrosis)
Fosfomycin (Monurol) 3 grams for one dose
Consider as a single dose in Emergency Department (e.g. patient non-compliant)
More expensive and may be less effective (58% efficacy compared with 70% for
Nitrofurantoin
)
Huttner (2018) JAMA 319(17): 781-9 +PMID:29710295 [PubMed]
Acute Uncomplicated UTI with risks for resistance (prior
Bactrim
use or international travel in last 6 months)
Nitrofurantoin
Avoid if GFR <30 ml/min (risk of interstitial pulmonary fibrosis)
Nitrofurantoin
100 mg orally four times daily for 5 days
Macrobid
100 mg orally twice daily for 5 days
Five days is sufficient course (previously used for 7 days)
Gupta (2007) Arch Intern Med 167(20):2207-12 [PubMed]
Fosfomycin (Monurol) 3 grams for one dose
Also see
Fluoroquinolone
s below
More severe disease or resistant UTI organisms:
Fluoroquinolone
s
Precautions regarding
Fluoroquinolone
s
Risk of
Tendinopathy
(and
Achilles Tendon Rupture
) and
Peripheral Neuropathy
Avoid if local resistance rate >10%
Renal dose adjustment required if GFR reduced
Although 3 day courses are listed, complicated UTI is treated for 10 days (up to 6 weeks in men)
Ciprofloxacin
250 mg PO bid for 3 days
In healthy older women, 3 days equivalent to 7 days
Vogel (2004) CMAJ 170:469-73 [PubMed]
Levofloxacin
250 mg every 24 hours for 3 days
Norfloxacin
400 mg PO bid for 3 days
Ofloxacin
200 mg PO bid for 3 days
Avoid
Moxifloxacin
and gemifloxacin (poor penetration into urine)
Antibiotics for
UTI in Pregnancy
See
Urinary Tract Infection in Pregnancy
Other antibiotics used in Urinary Tract Infection
Precautions
Beta lactams have lower efficacy in UTI
Cephalexin
(
Keflex
) 500 mg orally twice daily for 5-7 days
Amoxicillin
-Clavulanate (
Augmentin
) 875 mg orally twice daily for 5-7 days
Cefdinir
300 mg orally twice daily for 3-7 days
Sexually active young patients
Avoid
Nitrofurantoin
(
Macrobid
)
Staphylococcus
saprophyticus resistance
Consider
Chlamydia
sceening
Consider other
Sexually Transmitted Disease
Testing
Management
Special Circumstances
See
Recurrent Urinary Tract Infection
See
Ureteral Stent
ESBL (Extended Spectrum
Beta-Lactamase
) producing E Coli and
Klebsiella
Fosfomycin (cystitis)
Ertapenem
Management
Asymptomatic Bacteriuria
See
Asymptomatic Bacteriuria
Complications
Surgical
Perinephric Abscess
Urinary Tract Infection contiguous spread
Contrast with renal abscess (hematogenous spread)
Emphysematous Pyelonephritis
Seen in
Diabetes Mellitus
Requires surgical drainage (otherwise high mortality)
References
(2019) Sanford Guide, accessed on IOS 9/21/2019
Colgan (2011) Am Fam Physician 84(7): 771-6 [PubMed]
Ebell (2006) Am Fam Physician 73:293-6 [PubMed]
Gupta (1999) JAMA 281:736-8 [PubMed]
Gupta (2012) Ann Intern Med 156(5): ITC3-1 [PubMed]
Hooton (1997) Infect Dis Clin North Am 11:551-81 [PubMed]
Michels (2015) Am Fam Physician 92(9): 778-86 [PubMed]
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