Download Urinary Tract Infection (UTI)

URINARY TRACT
INFECTION
URINARY
Dr. Hani
Masaadeh
TRACT
MD,
Ph.D
INFECTION
1
URINARY TRACT INFECTION
Urinary tract is normally
sterile due to the fact
that bacteria moving
upwards are regularly
washed out by
urination
Normal flora found in the
urethra consist of
lactobacillus and
staphylococcus to name
a few
URINARY TRACT INFECTION
• Second most common
infection
following
respiratory infections
• UTI occur when bacteria
(E.
coli)
from
the
digestive tract get into
the opening of the
urinary
tract
and
multiply
• Bacteria first infect the
urethra, then move to
the bladder and finally
to the kidneys
• UTI tend to occur more
in women than men
URINARY
TRACT
INFECTION
Urinary Tract Infection

Upper urinary tract Infections:


Pyelonephritis
Lower urinary tract infections
Cystitis (“traditional” UTI)
 Urethritis (often sexually-transmitted)
 Prostatitis

Symptoms of Urinary Tract Infection
Dysuria
 Increased frequency
 Hematuria
 Fever
 Nausea/Vomiting (pyelonephritis)
 Flank pain (pyelonephritis)

Findings on Exam in UTI

Physical Exam:




CVA tenderness (pyelonephritis)
Urethral discharge (urethritis)
Tender prostate on DRE (prostatitis)
Labs: Urinalysis


+ leukocyte esterase
+ nitrites



More likely gram-negative rods
+ WBCs
+ RBCs
Culture in UTI


Positive Urine Culture = >105 CFU/mL
Most common pathogen for cystitis,
prostatitis, pyelonephritis:



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Escherichia coli
Staphylococcus saprophyticus
Proteus mirabilis
Klebsiella
Enterococcus
Most common pathogen for urethritis


Chlamydia trachomatis
Neisseria Gonorrhea
Lower Urinary Tract Infection Cystitis

Uncomplicated (Simple) cystitis


Complicated cystitis


In healthy woman, with no signs of systemic
disease
In men, or woman with comorbid medical
problems.
Recurrent cystitis
Uncomplicated (simple) Cystitis

Definition




Diagnosis


Dipstick urinalysis (no culture or lab tests needed)
Treatment



Healthy adult woman (over age 12)
Non-pregnant
No fever, nausea, vomiting, flank pain
Trimethroprim/Sulfamethoxazole for 3 days
May use fluoroquinolone (ciprofoxacin or levofloxacin) in
patient with sulfa allergy, areas with high rates of bactrimresistance
Risk factors:

Sexual intercourse

May recommend post-coital voiding or prophylactic antibiotic
use.
Complicated Cystitis

Definition




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Diagnosis



Females with comorbid medical conditions
All male patients
Indwelling foley catheters
Urosepsis/hospitalization
Urinalysis, Urine culture
Further labs, if appropriate.
Treatment



Fluoroquinolone (or other broad spectrum antibiotic)
7-14 days of treatment (depending on severity)
May treat even longer (2-4 weeks) in males with UTI
Special cases of Complicated
cystitis

Indwelling foley catheter


Try to get rid of foley if possible!
Only treat patient when symptomatic (fever, dysuria)


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Leukocytes on urinalysis
Patient’s with indwelling catheters are frequently colonized with
great deal of bacteria.
Should change foley before obtaining culture, if possible
Candiduria




Frequently occurs in patients with indwelling foley.
If grows in urine, try to get rid of foley!
Treat only if symptomatic.
If need to treat, give fluconazole (amphotericin if resistance)
Recurrent Cystitis
Want to make sure urine culture and
sensitivity obtained.
 May consider urologic work-up to
evaluate for anatomical abnormality.
 Treat for 7-14 days.

Pyelonephritis


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Infection of the kidney
Associated with constitutional symptoms – fever, nausea,
vomiting, headache
Diagnosis:


Treatment:

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Urinalysis, urine culture, CBC, Chemistry
2-weeks of Trimethroprim/sulfamethoxazole or fluoroquinolone
Hospitalization and IV antibiotics if patient unable to take po.
Complications:

Perinephric/Renal abscess:

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Suspect in patient who is not improving on antibiotic therapy.
Diagnosis: CT with contrast, renal ultrasound
May need surgical drainage.
Nephrolithiasis with UTI

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Suspect in patient with severe flank pain
Need urology consult for treatment of kidney stone
Prostatitis

Symptoms:
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
Diagnosis:
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Typical clinical history (fevers, chills, dysuria, malaise, myalgias,
pelvic/perineal pain, cloudy urine)
The finding of an edematous and tender prostate on physical examination
Will have an increased PSA
Urinalysis, urine culture
Treatment:


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Pain in the perineum, lower abdomen, testicles, penis, and with ejaculation,
bladder irritation, bladder outlet obstruction, and sometimes blood in the
semen
Trimethoprim/sulfamethoxazole, fluroquinolone or other broad spectrum
antibiotic
4-6 weeks of treatment
Risk Factors:



Trauma
Sexual abstinence
Dehydration
URINARY TRACT INFECTION
Importance of Urinary
Tract Infections is
demonstrated by the
fact that 20% of women
between ages 20-65
suffer one attack per
year
Approximately 50% of
women develop a UTI
during their lives and
there is a prevalence
rate of 5% per year of
asymptomatic or covert
bacteriuria in nonpregnant women
between ages 21 and 65
URINARY TRACT INFECTION
TYPES
LOWER TRACT INFECTION
UPPER TRACT INFECTION
URETHRITIS
PYELONEPHRITIS
PROSTATITIS
CYSTITIS
PERI NEPHRIC ABSCESS
URINARY TRACT INFECTION
AETIOLOGY
Background
1. Bacterial infections of urinary tract are a very common
reason to seek health services
2. Common in young females and uncommon in males under
age 50
3. Common causative organisms
• Escherichia coli (gram-negative enteral bacteria) causes most
community acquired infections
• Staphylococcus saprophyticus, gram-positive organism causes
10 – 15%
• Catheter-associated UTI’s caused by gram-negative bacteria:
Proteus, Klebsiella, Seratia, Pseudomonas
URINARY TRACT INFECTION
CLINICAL PRESENTATION
Cystitis
• dysuria (burning or discomfort on urination)
• frequency
• nocturia
• suprapubic discomfort
Urine is sterile
• Presence of inflammatory cells or
pathogens in urine indicate
a urinary tract infection (UTI) managed in
general medical practice
• Up to 50% of women will have a UTI at
some point in their life
• UTI uncommon in men except over the
age of 60 when urinary tract obstruction
due to prostatic hypertrophy may occur
Urinary System Infections
Serious problem in hospitals
Cause morbidity Pathogens can travel up
the ureters and reach the kidneys
UTIs are named according the place of
infection
‐In the urethra = Urethritis
‐In the bladder = Cystitis
‐In the kidneys = Nephritis
‐In the prostate (men) = prostatitis
Majority of infections are caused by bacteria,
though some are fungal
• Urine is an excellent culture medium for
bacteria
• Bacteria entering the bladder from the
external environment or blood passing
through the renal artery can normally be
flushed out during urination
• Infections occur when bacteria get into
the urine and remain
• More easily in women because of a
shorter urethra and absence of
bacteriostatic prostatic secretions (as in
men) • Catheterisation may also introduce
organisms into the bladder
Causative agents: mainly faecal bacteria
• Community acquired
• Escherichia coli
• Proteus mirabilis
• Klebsiella
pneumoniae
• Enterococcus faecalis
• Staphylococcus
species
• Hospital –acquired
• Pseudomonas
aeruginosa
• Candida albicans
• AND (community
acquired)
Mycobacterium
tuberculosis (renal TB –
will be a ‘sterile pyuria’
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Urinary Tract Infection (UTI)
Cystitis
1. Most common UTI
2. Remains superficial, involving bladder mucosa, which becomes
hyperemic and may hemorrhage
3. General manifestations of cystitis
 a. Dysuria
 b. Frequency and urgency
 c. Nocturia
 d. Urine has foul odor, cloudy (pyuria), bloody (hematuria)
 e. Suprapubic pain and tenderness
4. Older clients may present with different manifestations
 a. Nocturia, incontinence
 b. Confusion
 c. Behavioral changes
 d. Lethargy
 e. Anorexia
 f.
Fever or hypothermia
Urinary Tract Infection (UTI)
Pyelonephritis
1. Inflammation of renal pelvis and parenchyma
(functional kidney tissue)
2. Acute pyelonephritis
 a. Results from an infection that ascends to kidney
from lower urinary tract
Risk factors
 1. Pregnancy
 2. Urinary tract obstruction and congenital
malformation
 3. Urinary tract trauma, scarring
 4. Renal calculi
 5. Polycystic or hypertensive renal disease
 6. Chronic diseases, i.e. diabetes mellitus
 7. Vesicourethral reflux
Urinary Tract Infection (UTI)
Diagnostic Tests
a. Urinalysis: assess pyuria, bacteria, blood cells in urine;
Bacterial count >100,000 /ml indicative of infection
b. Rapid tests for bacteria in urine
 1.
 2.
Nitrite dipstick (turning pink = presence of bacteria)
Leukocyte esterase test (identifies WBC in urine)
c. Gram stain of urine: identify by shape and characteristic
(gram positive or negative); obtain by clean catch urine
or catheterization
Urinary Tract Infection (UTI)
d. Urine culture and sensitivity: identify infecting organism
and most effective antibiotic; culture requires 24 – 72
hours for results; obtain by clean catch urine or
catheterization
e. WBC with differential: leukocytosis and increased
number of neutraphils
URINARY TRACT INFECTION
PATHOGENESIS
BACTERIA GET ACCESS FROM URETHRA AND
ASCENDS
FEMALES ARE MORE PRONE DUE TO:
• SMALL URETHRA
• GRAM NEGATIVE ORGANISM RADIATE FROM PERI
ANAL AREA TO URETHRA
• SEXUAL INTERCOURSE
• SUSCEPTIBILITY OF EPITHELIUM
URINARY TRACT INFECTION
PATHOGENESIS
• FEMALE SEX AND INTERCOURSE PREDISPOSES
• PREGNANCY: URETERAL TONE AND URETHRAL
PERISTALSIS DECREASES
• OBSTRUCTION IN FREE FLOW OF URINE: TUMOR,
STRICTURE, CALCULI AND BPH ETC.
• CATHETERISATION, URETHRAL DILATATION,
CYSTOSCOPY
URINARY TRACT INFECTION
PATHOGENESIS
The normal bladder is capable of clearing itself
of organisms within 2 to 3 days of their
introduction.
Defense mechanisms
(1) the elimination of bacteria by voiding
(2) the antibacterial properties of urine and its
constituents
(3) the intrinsic mucosal bladder defense
mechanisms
(4) an acid vaginal environment (female)
(5) prostatic secretions (male)
URINARY TRACT INFECTION
PATHOGENESIS
Two potential routes :
(1) the hematogenous route, with
seeding of the kidney during the
course of bacteremia
(2) the ascending route, from the
urethra to the bladder, then from
the bladder to the kidneys via the
ureters.
URINARY TRACT INFECTION
PATHOGENESIS
Hematogenous Infection
Because the kidneys receive 20% to 25% of the
cardiac output, any microorganism that
reaches the bloodstream can be delivered to
the kidneys.
The major causes of hematogenous infection are
S. aureus, Salmonella species, P. aeruginosa,
and Candida species.
URINARY TRACT INFECTION
PATHOGENESIS
Hematogenous Infection
Chronic infections (skin, respiratory tract)
blood circulation
small abscess
renal pelvis
kidney (cortex)
renal tubular
renal papillary
URINARY TRACT INFECTION
PATHOGENESIS
ASCENDING INFECTION
The ability of host defense
Urinary tract mucosal cells damaged
The power of bacterial adhesions(toxicity)
organisms
urethra,periurethral tissues
bladder
ureters
renal pelvis
renal medulla
URINARY TRACT INFECTION
PATHOGENESIS
Voiding dysfunction is characterized by
some or all of the following:
urgency
frequency
dysuria
hesitancy
dribbling of urine
overt incontinence
secondary to a UTI or to local irritants such
as pinworm infestation
URINARY TRACT INFECTION
HISTORY AND PHYSICAL EXAMINATION
Age-related Risk Factors for UTI
• Advanced Age
• Fecal incontinence/impaction
• Incomplete bladder emptying or neurogenic
bladder
• Vaginal atrophy/estrogen deficiency
• Pelvic prolapse/cystocele
• Insufficient fluid intake/dehydration
• Indwelling foley catheter or urinary catheterization
or instrumentation procedures
URINARY TRACT INFECTION
CLINICAL PRESENTATION
Uncomplicated
• Cystitis
• Urethritis
• Female >>> male
• Sequel rare
URINARY TRACT INFECTION
CLINICAL PRESENTATION
Complicated
• Pyelonephritis
• Prostate obstruction
• Relapse +++
URINARY TRACT INFECTION
CLINICAL PRESENTATION
• Fever with chill & rigor
• Haematuria
• Strangury
• Ineffectual desire
• Cloudy urine
• Offensive urine
• Pain lower abdomen
Investigation: the specimen
• Mid-stream Urine (MSU) is the specimen
of choice
• Suprapubic urine
• Catheter urine
• In all cases, urine must be examined
immediately or stored at 4oC
• Contamination of urine is a big problem!!
• Should also determine the site of
infection
40
Diagnosis
• Urine culture yielding greater than 100,000 colonyforming units (105 CFU) per ml = significant bacteriuria.
• However, 30% or more of symptomatic women have
CFU counts below this level
• Therefore, urine cultures are no longer advocated –
pyuria (slide/dipstick)
• Leukocyte esterase test - sensitivity of 75-90% pyuria
associated UTI
• Dipstick test for nitrite a surrogate marker for bacteriuria
- not all uropathogens reduce nitrates to nitrite
• Gram stains of urine can be used to detect bacteriuria time-consuming and has low sensitivity
41
Standard procedures
• Investigation of UTI involves the detection
of bacteriuria together with evidence of an
inflammatory response
• Microscopy for pyuria and haematuria (can
also reveal other structures, e.g. crystals,
other cells, casts)
• Culture for detection of bacteria
• Sensitivity testing to advise on antibiotic
treatment
42
Microscopy
• Not always performed as it is time
consuming
• The finding of a rise in WBCs (pyuria)
should be linked to a bacteriuria
• May also see RBCs (haematuria); this is
potentially an important finding
• Microtitre plate and an inverted
microscope enables many urines to be
simply screened
43
White cells in urine
• In normal state, there is a continuous
secretion of WBCs into urine
• In a UTI caused by bacteria, neutrophils
may be secreted in large numbers
• Labs may report >200/μl (>200 x 103/ml)
and will suggest this as significant pyuria
• Lower numbers: < 103/ml are regarded as
not significant
44
Culture: procedure
• Cystitis is usually caused by a single
species of bacterium present at >105/ml
• Standard loopful of urine is streaked onto
a selective medium, e.g. CLED
• Typically 1μl
• Incubate overnight and count the colonies
• If a genuine UTI, should see >100
colonies; this = >100 bacteria/μl or >105/ml
45
Culture: interpretation
• >105/ml of a single species strongly suggests a
UTI
• 104-105/ml of a single species is equivocal –
needs repeat specimen for testing
• <104/ml is regarded as no significant growth
• >1 species in any numbers suggests
contamination
• Catheter and suprapubic urines should be
interpreted differently
46
Sensitivity testing
• Clinical isolates are tested against antibiotics
that
– a) are filtered by kidneys
– b) are usually effective against common agents
• Since UTIs are common, drugs should be
cheap!
• Typical course of treatment: 5-7 days orally,
resulting in sterile urine
• Nitrofurantoin, nalidixic acid, trimethoprim,
ampicillin + gentamicin, cephalosporins
47
Antibiotic sensitivities
48
URINARY TRACT INFECTION
TREATMENT
FLUID ++
ALKALI
EMPTYING OF BLADDER
HYGIENE
Recurrent U.T.I.s
that are reinfection.
Unresolved
Isolated
infections
infection
Classification of
U.T.I.
Recurrent infections resulting
from bacterial persistence.