Transcript Document
INFECTIONS OF THE
GENITOURINARY TRACT
DEPARTMENT OF UROLOGY IAŞI – 2013
INFECTIONS OF G-U TRACT
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)
INFECTIONS OF G-U TRACT
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
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
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
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
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
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
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
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)
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
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
INFECTIONS – BLADDER
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
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
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
INFECTIONS – PROSTATE
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
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)
SPECIFIC INFECTIONS
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)
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