Transcript Document

INFECTIONS OF THE
GENITOURINARY TRACT
DEPARTMENT OF UROLOGY IAŞI – 2013
INFECTIONS OF G-U TRACT
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EPIDEMIOLOGY
< 1 yr – bacteriuria: 2.7% M (phimosis), 0.7% F
1-5 yrs: 4.5% F, 0.5% M (congenital abnormalities; VUR or
obstruction)
6-15 yrs (functional abnormalities: dysfunctional voiding)
16-35 yrs: F 20% (sexual intercourse and diaphragm use
36-65 yrs: F  (gynecologic surgery and bladder prolapse), M 
(prostatic hypertrophy/obstruction, catheterization and surgery)
> 65 years:  (incontinence and chronic use of urinary catheters)
PATHOGENESIS – bacterial entry (4)
ascending: periurethral bacteria  urinary tract; short female
urethra + close proximity to the vaginal vestibule and rectum
INFECTIONS OF G-U TRACT
hematogenous – in immunocompromised patients and neonates;
Staph aureus, Candida sp and Mycobacterium tuberculosis
 lymphatogenous – spread through the rectal, colonic, and
periuterine lymphatics
 direct extension – intraperitoneal abscesses, vesico-intestinal or
vesico-vaginal fistulas; relapsing infection from an inadequately
treated focus in the prostate or kidney
Host Defenses
 unobstructed urinary flow (washout of ascending bacteria)
 urine specific characteristics (osmolality, urea concentration,
organic acid concentration and pH)  inhibit bacterial growth and
colonization; factors that inhibit bacterial adherence
(glycoprotein)
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INFECTIONS OF G-U TRACT
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presence of foreign bodies (stones, catheters, stents) allows the
bacteria to hide from the host defenses
cells of the urinary tract secrete chemoattractants (interleukin-8)
to recruit neutrophils to the area and limit tissue invasion
specific serum and urinary antibodies produced by the kidney 
 bacterial opsonization and phagocytosis and  bacterial
adherence
normal flora of the periurethral area (lactobacillus) or the
prostate (Zn)
in children, VUR  allow bacteria to be inoculated into the upper
tract and the infection to progress
aging:  susceptibility –  incidence of obstructive uropathy (M),
alteration in the vaginal and periurethral flora (F), soiling of the
perineum from fecal incontinence, neuromuscular diseases,
increased instrumentation and bladder catheterization
INFECTIONS OF G-U TRACT
Bacterial Pathogenic Factors
 Escherichia coli – uropathogens = limited number of O, K and H
serogroups  increased adherence to uroepithelial cells [fimbriae
(pili)], resistance to the bactericidal activity of human serum,
production of hemolysin ( tissue invasion and makes iron
available for the infecting pathogens) and  expression of K
capsular antigen (protects from phagocytosis by neutrophils)
CAUSATIVE PATHOGENS
 80% of the uncomplicated cystitis and pyelonephritis – E coli; less
common – Klebsiella, Proteus, Enterobacter spp and enterococci
 hospital-acquired UTIs – a wider variety of causative organisms,
including Pseudomonas and Staphylococcus spp
 children – Klebsiella and Enterobacter spp
INFECTIONS OF G-U TRACT
DIAGNOSIS
 relies on urinalysis and urine culture, from a voided or bagged
specimen, suprapubic aspiration or from a urinary catheter
 occasionally, localization studies may be required to identify the
source of the infection
Urinalysis
 rapid screen for UTIs (urine dipstick) – leukocyte esterase (white
blood cells) and urinary nitrite
 microscopic examination for WBCs (> 3 per HPF) and bacteria
Urine Culture
 quantitative culture for specific bacteria: > 100,000 CFU/mL (to
exclude contamination)
 clinically significant UTI can occur with < 100,000 CFU/mL bacteria
INFECTIONS OF G-U TRACT
Localization Studies
 upper urinary tract localization: bladder irrigated with sterile
water, ureteral catheter placed into each ureter, specimen
collected from the renal pelvis
 in M, infection in the lower urinary tract (Meares and Stamey);
specimen collected at the beginning of the void (urethra),
midstream specimen (bladder), prostate massaged and void
(prostate)
ANTIBIOTICS
 goal – to eradicate the infection by selecting the appropriate
antibiotics that would target specific bacterial susceptibility
INFECTIONS OF G-U TRACT
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general principles for selecting the appropriate antibiotics
 infecting pathogen (antibiotic susceptibility, single-organism
vs. poly-organism infection, pathogen vs. normal flora,
community vs. hospital-acquired infection)
 patient (allergies, underlying diseases, age, previous
antibiotic therapy, other medications currently taken,
outpatient vs. inpatient status, pregnancy)
 the site of infection (kidney vs. bladder vs. prostate)
certain antimicrobial agents – adjusted in the presence of liver or
renal diseases
in patients with recurrent UTIs or those at risk for UTI (children
with VUR) – prophylactic antibiotics
INFECTIONS OF G-U TRACT
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trimethoprim-sulfamethoxazole (TMP-SMX) – except Enterococcus
and Pseudomonas spp; interferes with the bacterial metabolism
of folate; highly effective and relatively inexpensive; adverse
reactions: hypersensitivity reactions, rashes, gastrointestinal
upset, leukopenia, thrombocytopenia and photosensitivity
fluoroquinolones – broad spectrum of activity, except Streptococci
species and anaerobic bacteria; interfere with the bacterial DNA
gyrase, preventing bacterial replication; highly effective but
relative expensive; adverse reactions: mild gastrointestinal
effects, dizziness and lightheadedness; should not be used in
pregnant patients and in children (damage to developing
cartilage)
INFECTIONS OF G-U TRACT
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nitrofurantoin – good activity against most gram-negative bacteria
(except Pseudomonas and Proteus spp), Staphylococci and
Enterococci species; inhibits bacterial enzymes and DNA activity;
highly effective and relative inexpensive; adverse reactions;
gastrointestinal upset, peripheral polyneuropathy and
hepatotoxicity, pulmonary hypersensitivity reaction and
interstitial changes
aminoglycosides – used in the treatment of complicated UTI;
highly effective against most gram-negative bacteria; combined
with ampicillin, are effective against enterococci; inhibit bacterial
DNA and RNA synthesis; adverse effects: nephrotoxicity and
ototoxicity; regimen is directed toward obtaining higher peak and
lower trough levels (more effective microbial killing while
reducing toxicity)
INFECTIONS OF G-U TRACT
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cephalosporins – good activity against most uropathogens; inhibit
bacterial cell wall synthesis; adverse reactions: hypersensitivity
and gastrointestinal upset; in children with febrile
UTI/pyelonephritis, oral third-generation cephalosporins
(cefixime) are safe and effective
aminopenicillins (amoxicillin and ampicillin) – good activity
against Enterococci, Staphylococci, E coli and Proteus mirabilis;
addition of ß-lactamase inhibitors (clavulanic acid) makes more
active against the gram-negative bacteria; adverse reactions;
hypersensitivity, gastrointestinal upset and diarrhea
INFECTIONS OF THE KIDNEY
ACUTE PYELONEPHRITIS
 inflammation of the kidney and renal pelvis, and its diagnosis is
usually made clinically
Presentation and Findings
 chills, fever and costovertebral angle tenderness; often
accompanying lower-tract symptoms (dysuria, frequency and
urgency); sepsis may occur (20-30% of urosepsis)
 E coli is the most common causative organism (80%), Klebsiella,
Proteus, Enterobacter, Pseudomonas, Serratia and Citrobacter
spp.; gram-positive bacteria (Streptococcus faecalis and S aureus)
Imaging
 renal US – rule out concurrent urinary tract obstruction; enlarged
kidney, hypoechogenic parenchyma
INFECTIONS OF THE KIDNEY
CT scan (not necessary unless diagnosis is unclear or patient is not
responding to therapy): constriction of peripheral arterioles and
reduced perfusion of the affected renal segments (segmental,
multifocal or diffuse – areas of reduced signal density), renal
enlargement, attenuated parenchyma and a compressed
collecting system
 radionuclide study (99mTc-DMSA): detecting the perfusion defects
of pyelonephritis
Management
 depends on the severity of the infection; toxicity because of
associated septicemia  hospitalization
 empiric therapy – i.v. ampicillin and aminoglycosides or
amoxicillin with clavulanic acid or a third-generation
cephalosporin
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INFECTIONS OF THE KIDNEY
parenteral therapy – until the patient defervesces; if bacteremia is
present, parenteral therapy should be continued for an additional
7-10 days, then oral treatment for 10-14 days
 patients who are not severely ill, outpatient treatment with oral
antibiotics: fluoroquinolones or TMP-SMX for 10-14 days
EMPHYSEMATOUS PYELONEPHRITIS
 necrotizing infection – presence of gas within the renal
parenchyma or perinephric tissue
 80-90% have diabetes; the rest – associated with urinary tract
obstruction (calculi) or papillary necrosis
Presentation and Findings
 fever, flank pain and vomiting that fails initial management with
parenteral antibiotics; pneumaturia may be present: bacteria – E
coli, Klebsiella pneumoniae, Enterobacter cloacae
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INFECTIONS OF THE KIDNEY
Radiographic Imaging
 diagnosis: gas overlying the affected kidney on a plain abdominal
radiograph (KUB); CT scan – more sensitive in detecting the
presence of gas in the renal parenchyma than renal US
Management
 essential – prompt relief of urinary obstruction (percutaneous
drainage), control of blood glucose, fluid resuscitation and
parenteral antibiotics
 mortality: 11-54%; poor prognostic factors: high serum creatinine
level, low platelet count, the presence of renal/perirenal fluid +
bubbly/loculated gas pattern or gas in the collecting system
 nephrectomy may be required; 3-4 weeks of parenteral antibiotic
therapy is usually required
INFECTIONS OF THE KIDNEY
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RENAL/PERINEPHRIC ABSCESS
severe infection that leads to liquefaction of renal tissue,
subsequently sequestered
rupture out into the perinephric space  perinephric abscesses;
extend beyond the Gerota's fascia  paranephric abscesses
hematogenous spread of staphylococci (infected skin lesions) 
abscesses in the renal cortex
patients with diabetes, undergoing hemodialysis or i.v. drug
abusers – high risk
abscesses due to gram-positive bacteria are less prevalent; those
caused by E coli or Proteus species are becoming more common –
formed in the corticomedullary junction, in conjunction with
underlying urinary tract abnormalities (stones or obstruction)
INFECTIONS OF THE KIDNEY
Presentation and Findings
 fever, flank or abdominal pain, chills and dysuria
 flank mass may be palpated
 urinalysis – usually WBCs; normal in approx. 25% of the cases
 urine cultures – 1/3; blood cultures – 1/2
Imaging
 US – anechoic mass within or displacing the kidney/echogenic
fluid collection that blends with the fat within Gerota's fascia
 CT scan – enlarged kidney with focal areas of hypoattenuation 
mass with a rim of contrast enhancement ("ring" sign); thickening
of Gerota's fascia, stranding of the perinephric fat or obliteration
of the surrounding soft-tissue planes
INFECTIONS OF THE KIDNEY
Management
 appropriate antibiotic therapy – empiric therapy with broadspectrum antibiotics (ampicillin or vancomycin + aminoglycoside
or third-generation cephalosporin)
 w/o respose within 48 h  percutaneous drainage under CT or US
guidance  culture of the drained fluid
 still not resolved  open surgical drainage or nephrectomy
 evaluation for underlying urinary tract abnormalities (stone or
obstruction)
XANTHOGRANULOMATOUS PYELONEPHRITIS
 form of chronic bacterial infection of the kidney – hydronephrotic
and obstructed  severe inflammation and necrosis of the kidney
parenchyma
INFECTIONS OF THE KIDNEY
foamy lipid-laden histiocytes (xanthoma cells)  renal clear cell
carcinoma
Presentation and Findings
 history of urolithiasis (35%)
 flank pain, fever, chills and persistent bacteriuria
 physical examination – flank mass often palpated
 urinalysis – WBCs and protein, urine culture – E coli, Proteus
 anemia, hepatic dysfunction (50%)
Imaging
 CT scan (most reliable) - large heterogeneous, reniform mass;
renal parenchyma marked with multiple water-density lesions
(dilated calyces or abscesses); inflammatory process extend to
perinephric fat, retroperitoneum and adjacent organs (psoas
muscle, spleen, colon or great vessels)
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INFECTIONS OF THE KIDNEY
renal US – enlarged kidney with a large central echogenic area and
anechoic parenchyma
 misdiagnosed as a renal tumor – similar appearances
Management
 nephrectomy  diagnosis is made pathologically
PYONEPHROSIS
 bacterial infection of a hydronephrotic & obstructed kidney 
suppurative destruction of renal parenchyma (loss of renal
function)
 sepsis may rapidly ensue  rapid diagnosis and management
Findings
 high fever, chills, flank pain & pyuria
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INFECTIONS OF THE KIDNEY
bacteriuria & leukocyturia (may be absent with complete
obstruction!)
 US – persistent echoes in the lower part of the collecting system,
fluid-debris level with echoes that shift with positional changes,
strong echoes with acoustic shadowing (air in the collecting
system), dilated collecting system, renal or ureteral calculi
 IVU – opacities, nonfunctional kidney
Management
 immediate institution of antibiotic therapy and drainage of the
infected collecting system (percutaneous nephrostomy or ureteral
stent)
 then, treatment of the cause (urolithiasis, UPJ obstruction etc.) or
nephrectomy
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INFECTIONS – BLADDER
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ACUTE CYSTITIS
urinary infection of the lower urinary tract (bladder); F > M
irritative voiding symptoms (dysuria, frequency & urgency)
low back and suprapubic pain, hematuria, and cloudy/foulsmelling urine
urinalysis – WBCs, hematuria; urine culture
management – short course of oral antibiotics (TMP-SMX,
nitrofurantoin, fluoroquinolones) – 3-5 d
RECURRENT CYSTITIS/UTI
caused by bacterial persistence ( removal of the infected source)
or reinfection with another organism ( preventive therapy)
INFECTIONS – BLADDER
bacterial persistence  imaging (US, IVU, cystoscopy, CT scan,
bacterial localization studies, retrograde pyelograms)
 bacterial reinfection  evidence of vesicovaginal or vesicoenteric
fistula
Management
 bacterial persistence  surgical removal of the infected source
(urinary calculi)
 bacterial reinfection  prophylactic antibiotics (low-dose
continuous or intermittent self-start), surgical repair of fistulas
 related to sexual activity  frequent emptying of the bladder &
single dose of antibiotic, after intercourse
 intravaginal estriol, lactobacillus vaginal suppositories and
cranberry juice taken orally
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INFECTIONS – PROSTATE
ACUTE BACTERIAL PROSTATITIS
 inflammation of the prostate associated with a UTI  ascending
urethral infection or reflux of infected urine from the bladder into
the prostatic ducts
Presentation and Findings
 abrupt onset of fever, chills, malaise, arthralgia, myalgia, lower
back/rectal/perineal pain and urinary symptoms (frequency,
urgency, dysuria  acute urinary retention)
 DRE – tender, enlarged irregular and warm gland
 urinalysis – WBCs, occasionally hematuria
 leukocytosis; PSA 
 ! urethral catheterization & prostatic massage should be avoided
 bacteremia
INFECTIONS – PROSTATE
US – residual urine; TRUS – non-responsive to conventional
therapy
Management
 trimethoprim or fluoroquinolones (high drug penetration into
prostatic tissue) for 4-6 wks. (prevent complications – chronic
prostatitis, abscess formation)
 sepsis, immunocompromised pts., acute urinary retention or
significant medical comorbidities  hospitalization and parenteral
antibiotics (amoxyclav + aminoglycoside)
 urinary retention  suprapubic catheter
CHRONIC BACTERIAL PROSTATITIS
 relapsing, recurrent UTI caused by the persistence of pathogen in
the prostatic fluid, despite antibiotic therapy
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INFECTIONS – PROSTATE
dysuria, urgency, frequency, nocturia and low back/perineal pain
 others are asymptomatic, but have bacteriuria
 DRE is often normal; occasionally, tenderness, firmness or
prostatic calculi
 urinalysis – WBCs and bacteriuria; PSA may be 
 diagnosis – identification of bacteria from prostate expressate or
urine specimen after a prostatic massage (4-cup test)
 TRUS – if prostatic abscess is suspected
Management
 antibiotic therapy – similar to acute bacterial prostatitis, but up to
3-4 mo.
 alpha blocker – to reduce symptom recurrences
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INFECTIONS – PROSTATE
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cure is not often achieved  poor penetration of antibiotic into
prostatic tissue & isolation of the bacterial foci within the prostate
recurrent episodes of infection  suppressive antibiotic (TMPSMX 80/240 mg daily, nitrofurantoin 100 mg daily, or ciprofloxacin
250 mg daily)
refractory disease  ? TUR-P
EPIDIDYMITIS
most cases < 35 years – due to sexually transmitted organisms (N
gonorrhoeae, C trachomatis); in children and older men – E coli
epididymis  testis
INFECTIONS – PROSTATE
Presentation and Findings
 severe scrotal pain – may radiate to the groin or flank; scrotal
enlargement (inflammation of epididymis/testis or reactive
hydrocele); symptoms of urethritis, cystitis or prostatitis
 physical examination – enlarged and red scrotum; thickened
spermatic cord
 urinalysis – WBCs and bacteria in the urine or urethral discharge;
blood analysis – leukocytosis
 epididymitis  acute testicular torsion
 scrotal Doppler US – presence of blood flow in the testis
 radionuclide scanning – uptake of the tracers into the center of
the testis
INFECTIONS – PROSTATE
scrotal US – enlarged epididymis with increased blood flow;
reactive hydrocele or testicular involvement
Management
 antibiotic treatment
 gonococcal  ceftriaxone (250 mg i.m.) or fluoroquinolones
(ciprofloxacin 250 mg or norfloxacin 800 mg)
 nongonococcal  tetracycline or erythromycin (500 mg 4
times daily) or doxycycline (100 mg twice daily) for 7-14 days
 bed rest, scrotal elevation, nonsteroidal anti-inflammatory agents
 treatment of the sexual partner
 abscess  open drainage
 chronic, relapsing epididymitis, scrotal pain  epididymectomy
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SPECIFIC INFECTIONS
specific infections – caused by specific organisms, clinically unique
disease, specific pathologic tissue reactions
TUBERCULOSIS
 young adults (60% of pts. – age 20-40); M > F
Etiopathogenesis
 Mycobacterium tuberculosis
 lungs  hematogenous route  GU organs
 kidney  bladder
 prostate  bladder, epididymis  testis
 renal parenchyma (no symptoms)  calyces  pus and organisms
discharged into urine  symptoms (of cystitis)
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SPECIFIC INFECTIONS
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infection of the pelvic mucosa and the ureter  stricture and
(uretero)hydronephrosis
caseous breakdown of renal tissue + Ca laid down in the
reparative process
fibrosis of ureter  shortened and straightened  "golf-hole"
ureteral orifice (incompetent valve)
bladder – vesical irritability; tubercles form, coalesce & ulcerate
(bleeding); fibrosis & contraction of the bladder (marked
frequency); ureteral reflux or stenosis  ureterohydronephrosis
extensive epididymal infection  abscess formation 
spontaneous rupture  permanent sinus of the scrotal skin
SPECIFIC INFECTIONS
Pathology
 granuloma (basic lesion in TB) –
aggregation of histiocytic cells
(vesicular nucleus and clear cell
body), that can fuse with neighboring cells  epithelioid reticulum;
at the periphery are large cells with
multiple nuclei (giant cells)
 virulence of organism  resistance
of patient  caseation and cavitation  healing by fibrosis and
calcification
 bladder – tubercles can be seen endoscopically (white or yellow
raised nodules surrounded by a halo of hyperemia)
SPECIFIC INFECTIONS
Clinical findings
 symptoms – vesical in origin (cystitis)
 nonspecific complaints – generalized malaise, fatigability, lowgrade persistent fever, night sweats
 epididymis – painless or mildly painful swelling (including vas
deferens), chronic draining sinus
 evidence of extraGU tuberculosis (lungs, bone, lymph nodes,
tonsils, intestines)
Laboratory
 persistent pyuria, acid pH, without organisms on usual cultures
 acid-fast stain (Ziehl-Neelsen), cultures (Löwenstein-Jensen)
SPECIFIC INFECTIONS
X-Ray findings
 KUB – calcifications in the renal parenchyma
 IVU – “moth-eaten” ulcerated calyces; obliteration of calyces;
(U)HN due to ureteral stenosis from fibrosis; abscess cavities that
connect with calyces; multiple ureteral strictures, with shortening
and straightening of the ureter; non-functional kidney due to
complete ureteral occlusion or renal destruction (autonephrectomy)  retrograde ureteropyelogram
 US, CT
Instrumental examination
 cystoscopy – tubercles or ulcers  biopsies + pathology
SPECIFIC INFECTIONS
Treatment
 Medical (2-3 m, 7/7 + 4-3 m, 2-3/7)
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isoniazid (INH), 200–300 mg orally once daily;
rifampin (RMP), 600 mg orally once daily;
ethambutol (EMB), 25 mg/kg daily for 2 months, then 15 mg/kg orally
once daily;
streptomycin, 1 g intramuscularly once daily;
pyrazinamide, l.5–2 g orally once daily.
Surgical – urinary diversion or augmentation cystoplasty
(ileocystoplasty, ileocecocystoplasty, sigmoidocystoplasty),
nephrectomy, epididymectomy