Download الشريحة 1

Specific Infections of the
Genitourinary System
Tuberculosis of the genitourinary tract
M. tuberculosis is the cause of most human disease,
and humans are the only reservoir for this organism.
M. Bovis could also cause G.U TB
*TB is the most common opportunistic infection in
AIDS patients
-Genitourinary TB is caused by metastatic spread of
the organism through the bloodstream during the
initial infection.
The kidney is usually the primary organ infected in
urinary disease, and other parts of the urinary tract
become involved by direct extension
Pathology and Clinical Features
Urologists should always consider the diagnosis of
genitourinary TB in a patient presenting with vague,
longstanding urinary symptoms for which there is no
obvious cause.
-G.U TB called great imitator
-Most patients affected are aged 20 to 40 years, and
the male to female ratio is 2:1
the symptoms of renal TB usually do not appear for 3
to 10 or more years after the primary infection
The patient usually complains of frequent painless
micturition (frequency)
The urine is classically characterized by a sterile
pyuria
microscopic hematuria is present in up to 50%
Renal TB
caused by the activation of a prior bloodborne renal
infection
Caseating granulomas develop and consist of
Langhans giant cells surrounded by lymphocytes and
fibroblasts
The healing process results in fibrous tissue and
calcium salts being deposited, producing the classic
calcified lesion.
One may also develop papillary necrosis and
strictures in the calyceal stem or at the pelviureteral
junction.
TB of ureter
Tuberculous ureteritis is always an extension of the
disease from the kidney and leads to fibrosis and
stricture formation.
The site most commonly affected is the ureterovesical
junction (UVJ)
TB of the testes & epididymis
Tuberculous epididymitis may be the first and only
presenting symptom of genitourinary TB.
The usual presentation is a painful, inflamed scrotal
swelling that is difficult to differentiate from acute
epididymo-orchitis
TB of the testis is almost always secondary to
infection of the epididymis via direct extension
GU TB should be considered in the presence of:-
(l) chronic cystitis that refuses to respond to adequate
therapy,
(2) the finding of sterile pyuria,
(3) gross or microscopic hematuria,
(4) a nontender, enlarged epididymis with a beaded
or thickened vas,
(5) a chronic draining scrotal sinus, or
(6) induration or nodulation of the prostate and
thickening of one or both seminal vesicles
(especially in a young man).
urinalysis
-sterile pyuria is the classic urinary finding on routine
urinalysis and culture.
-Up to 50% of patients will also have microhematuria
-Urine culture is traditionally used for diagnosis
because acid-fast bacilli (AFB) smears are often
negative
*Cultures, however, take 6 to 8 weeks because
M. tuberculosis is slow growing, with a doubling time
of 15 to 20 hours.
Furthermore, the organism is intermittently excreted;
therefore, at least three, but preferably five,
consecutive early morning specimens of urine should
be cultured
Plain radiographs of the urinary tract are important
because they show calcification in the kidneys and in
the lower genitourinary tract
-High-dose intravenous urography (IVU) has
traditionally been the gold standard tool to diagnose
and evaluate genitourinary TB.
CT has replaced IVU for the diagnosis and evaluation
of genitourinary TB
*It is at least the equal of IVU in identifying
-calyceal abnormalities,
-hydronephrosis or hydroureter,
-autonephrectomy, amputated infundibulum,
-urinary tract calcifications, and
-renal parenchymal cavities
*However,these findings are not specific
treatment
The cornerstone of antituberculous therapy is
multidrug treatment to decrease the duration of
therapy and diminish the likelihood that drug-resistant
organisms will develop
*the current focus is on organ preservation and
reconstruction as opposed to (the previous believe )
excision
Furthermore, when surgical intervention is mandated
it should be delayed until medical therapy has been
administered for at least 4 to 6 weeks
Urinary Schistosomiasis
is a chronic disease caused by schistosomes, a genus
of digenetic parasitic trematodes
The paired adult male and female worms cohabit the
venous plexuses of the abdominal viscera.
*S. mansoni and S. japonicum reside in the mesenteric
veins, leading to gastrointestinal or hepatic disease,
whereas S. haematobium worm pairs dwell
principally in the perivesical venous plexus and cause
urinary schistosomiasis
Etiology:
fork-tailed larvae, (cercariae) enter the skin from
infested water, lose their tails as they penetrate the
skin, termed schistosomules, cause allergic skin
reaction
through lymphatic & veins enter general circulation
worms reach vesico-prostatic plexus survive &
mature.
the adult digenetic trematode M. (10x3mm) in its
schist carry the long slim (20x0.25mm) F. in the
prostatovesical plexus where the F. penetrate the
venule to lay her eggs in the subepithelial layer
(tubercles).
histolyses+ contraction of detrusor ms. The living
ova extruded with urine.
hatch in the fresh water into (ciliated miracidia)—
specific snail form sporocyts –cercaria leave the snail
to complete their life cycle
6
Worms continue to develop
in the liver, then migrate to blood
vessels around the urinary bladder
7
6
7
Adult worms end up in
veins
around the bladder.
Eggs penetrate the bladder
wall
and are passed out with the
urine
5
…and enter unbroken skin,
then migrate through blood vessels
to the liver
1
Eggs are passed out in
urine
4
Cerariae leave the
snail…
2
Miricidia hatch from eggs in
water
3
Larval multiplication in Bulinis snail
Inactive urinary schistosomiasis, which occurs after
adult worms have died, is characterized by the
absence of viable eggs in tissues or urine and the
presence of “sandy patches”—relatively flat, tan
mucosal lesions of various depth, often not sharply
defined
The immune response to the different stages of
S. haematobium is very complex
These responses are ineffective against the adult
worms, which by themselves do not produce
significant disease in the host
another pathologic sequelae of schistosomiasis is
bladder cancer which usually has early onset
(40 to 50 years) and a high frequency of squamous
cell carcinomas (60% to 90%)
Clinical presentation
active schistosomiasis is usually presented with
terminal hematuria & dysuria
Hematuria may be sufficient to cause anemia
*The schistosomal “contracted bladder” syndrome
occurs most frequently during the late chronic
active stage, when egg burdens in tissue are highest.
It manifests as constant, deep lower abdominal and
pelvic pain, urgency, frequency, and incontinence
Although symptoms may abate & infection enter
quiescent period, silent obstructive uropathy may
develop throughout this phase, as fibrosis replaces
polypoid lesions and the bladder and ureters undergo
irreversible damage
In chronic inactive phase Signs and symptoms at
this stage are caused by sequelae and complications
rather than by the schistosomal infection itself
obstructive uropathy, nonfunctioning kidneys are
commonly found
bladder ulcers which occur in two types
-acute schistosomal ulcers will rarely present in the
active stage, when a necrotic polyp sloughs into the
urine.
-The more common chronic schistosomal ulcer is a
late sequelae of heavy infection. This lesion is
associated with a constant “burning” micturition and
intense pelvic and suprapubic pain
Diagnosis
GUE, the preence of terminally spined eggs in
urinary sediment is diagnostic of active S.
haematobium infection
Radiographically, The classic presentation of a
calcified bladder, which looks like a fetal head in the
pelvis, is pathognomonic of chronic urinary
schistosomiasis
Medical Management
All patients with schistosomiasis should be treated
regardless of the intensity or apparent activity of
their infection
Praziquantel is the drug of choice for all
Schistosoma species
Cure rates with praziquantel are 83% to 100%
The current recommendation is two oral doses of 40
mg/kg in 1 day programs
Praziquantel is extremely well tolerated, with
gastrointestinal complaints (nausea, vomiting,
diarrhea, and anorexia) being the major side effects.
Headache, dizziness, and fever are occasionally
reported.
The lack of serious side effects has made it the agent
of choice in national mass chemotherapy