URINARY TRACT INFECTION
IN ADULTS
Incidence
UTI (urinary tract infection) -common, affecting all ages and
both sexes
the most common but one infections (the first -breath
infections)
Clinical syndromes associated with UTI:
septicaemia (urosepsis)
renal infection
pyelonephritis
pyonephrosis
renal abscess
peri-et paranephric abscess
Methods of introducing UTI
Ascending infection -via urethra to bladder,
reflux of infected urine up to ureter and/or
spread of organisms along peri-ureteric
lymphatics
infection via a fistula (e.g. vesico-colic)
heamatogenous infection (via renal artery)
Aetiology and pathogenesis
the urinary tract is normally sterile above the distal
urethra
the chiefly defence mechanisms:
hydrokinetic = the dilution of bacteria by the
flow of urine
mucosal = mainly secretion of immunoglobulin
A (Ig A) and phagocytic capability of the
urothelium itself
Factors predisposing to infection
UTI -commoner in women:
due to shorter urethra
opening of urethra at the vaginal vestibule, which is
readily contaminated with faecal organism
in many young women, infection are precipitated by
sexual intercourse, bacteria-laden secretion from the
perineum entering the urethra during sexual activity (so
called honey-moon cystitis)
In either sex UTI may develop:
Incomplete bladder emptying (residual urine) due to
outflow obstruction (BPH, urethral stricture …)
Factors predisposing to infection cont. …
Bladder diverticula
Neuropathic bladder
Upper urinary tract stasis due to obstruction of
ureter, megaureter, stones
Vesico-ureteric reflux interferes with both ureteric
and bladder emptying and is commonly
accompanied by infection
Factors predisposing to infection cont. …
Calculi, bladder tumours and foreign bodies (e. g.
catheters) are predispose to infection, as may
instrumentation of the urinary tract
Factors that suppress the immune response
(diabetes mellitus, cytotoxic or
immunosuppressive agents)
Common urinary pathogens cont. …
II. Haematogenous infection
Bacteria -mycobacterium tuberculosis
Fungi
Parasites -schistosoma spp
Viruses -cytomegalovirus, adenovirus type 11
Clinical manifestation
Symptoms
Lower UTI
Voiding symptoms -frequency, urgency, micturition with discomfort,
burning sensation (= dysuria)
Occasionally haematuria
Upper UTI
loin pain
Systemic disturbance -fever, sweating, rigors
Some patients have lower UTI as well (often upper UTI follow lower
UTI)
Physical signs
Fever and tachycardia
Tenderness in the loin and in the suprapubic region
Clinical manifestationcont. …
Diagnosis
the presence of pus cells on microscopy
the presence of significant number (over 10 5 per
ml) of organism in a mid-stream specimen of urine
(MSU)
microbiology laboratories determines antibiotic
sensitivities
specialised microbiological techniques may be
required in certain circumstances (e. g. Tuberculosis,
fungal infection, viral infection)
Clinical manifestationcont. …
Further investigation
Cystitis in young sexually active women investigation is
not required for the first attack unless it is accompanied
by haematuria or loin pain
investigation is indicated in this group of women for
recurrent infections, in older women, pregnant women,
children, men, diabetes mellitus, neuropathy, known
urinary stones or urinary tract anomaly -urinary tract
ultrasound, if indicated IVU, blood count, the serum
urea and creatinine
Clinical manifestationcont. …
Treatment
Antibiotics commonly used to treat UTI :
Nitrofurantoin
Co-trimoxazol (sulfamethoxazol + trimethoprim) and
trimethoprim alone
Ampicillin, amoxycillin, co-amoxycillin (clavulic acid +
amoxicillin)
Gentamicin
Quinolones (norfloxacin, ciprofloxcin)
Treatment cont. …
Cefalosporins
High fluid intake and regular emptying of the
bladder to promote hydrostatic clearance of
bacteria
Attention to personal hygiene for women with
recurrent infection
In patients with collections of infected urine or
pus (e.g. pyonephrosis, perinephric abscess)
drainage is usually required
UPPER URINARY TRACT
INFECTIONS
Acute renal infection
Most result from ascending infection (75% of
patients have preceding lower-tract symptoms)
Some they are result of haematogenous spread
There is important to distinguish between infection
alone and infection combined with upper-tract
obstruction; the latter combination may lead to rapid
obstruction of renal tissue unless prompt drainage of
the obstructed kidney is established
Pathology
Acute pyelonephritis
Acute inflammation of the pelvic epithelium, with
bacteria entering the collecting duct and fornices to
produce inflammation of the renal parenchyma
Renal carbuncle
An abscess in the renal parenchyma and is usually
due to haematogenous spread of organisms
(Typically staph. aureus from foil, infected infusion
site, contaminated needles in drug addicts)
Pathology cont. …
Pyonephrosis
Infection within an obstructed kidney rapid
destruction of kidney
Perinephric abscess
It result form any of the above infective processes
Initially the infection is confined by Gerota’s fascia
(= perinephric abscess), but may rupture through
this (= paranephric abscess) and to reach the skin (in
Petit’s lumber triangle) , the psoas muscle or the
bowel; it may even rupture through the diaphragm
to reach the pleura and lungs
Pathology cont. …
Clinical symptoms
Loin pain, fever, tachycardia, scoliosis in sever cases
Mass may be palpable in the loin
Septicaemia and shock
Investigation
Urine should be examined for pus cells and bacteria
(urine culture), blood culture (all patients with
pyrexia or clinical suspicious of septicaemia)
Ultrasound
urinary tract, liver, spleen, a plain abdominal X-ray,
chest X-ray, IVU
Management
Septicaemic patient
rapid intravenous fluid replacement
intravenous hydrocortisone or methylprednisolone
parenteral bactericid antibiotics
Subsequent management depend on the pattern of
infection, basic treatment is are antibiotics .
Management cont. …
Acute pyelonephritis
antibiotics for 7-14 days, guided by the result of
urine culture and sensitivity
Renal carbuncle
drainage
by aspiration of the abscess under ultrasound or CT
control
by open surgery
Management cont. …
Pyonephrosis
Drainage by percutaneous nephrostomy or with a
ureteric catheter passed retrogradely from the
bladder at cystoscopy
After improvement ascendant pyelography or
descendent pyelography (nephrostogram)
identification of obstruction
renal scintigraphy determines remaining renal
function
Management cont. …
treatment of obstruction (e. g. ureteroscopy for
ureterolithiasis, nephrectomy if kidney function is by
scintigraphy under 10 (15) %)
Perinephric abscess
surgical drainage or nephrectomy, if function in the
affected kidney is very poor
Chronic pyelonephritis
combination of renal scarring and urinary infection
it may follow vesico-ureteric reflux and infection
repeated episodes of acute pyelonephritis
differential diagnosis of other types of interstitial
nephritis or hypoplasia of kidney is difficult
Treatment
Eradication of infection to prevent further renal
damage. Nephrectomy, if:
renal function is under 10 (15) %
sever secondary hypertension
Xantogranulomatous pyelonephritis
The result of granulomatous reaction within
kidney to chronic infection
Treatment
nephrectomy
LOWER URINARY TRACT
INFECTIONS
Acute bacterial cystitis
usually result of ascending bacterial infection from the
perineum
particularly common in women (due to short urethra)
Clinical features:
Frequency and urgency of micturition with dysuria
There may be suprapubic pain, urine often has a fishy smell
or may be blood stained = haemorrhagic cystitis)
Association of loin pain and fever suggest spread of infection
to the kidney (acute pyelonephritis)
LOWER URINARY TRACT
INFECTIONS cont. …
Management
MSU (including urine culture) before treatment to confirm
the diagnosis
Antibiotics for a 5 days period this can be changed, if
necessary, on the basis of antibiotics sensitivity tests
Analgetics and spasmolytics (the best in combination e.g.
Algifen®)
Resolution of symptoms = MSU to repeat at 2 weeks and at
3 months to ensure eradication of infection
Chronic and recurrent bacterial
cystitis
Clinical symptoms
Similar to acute cystitis
Histologically cystic changes ( cystitis cystica) and squamous
metaplasia
Treatment
In women self-help advice
Increase fluid intake
Pass urine every 2 hours
Regular washing of the vulva and vaginal introitus
Wipe from front to back after bowel actions
Treatment cont. …
Empty the bladder after sexual intercourse (if the symptoms
are precipitated by sex)
Infection ( antibiotics )
Long-term low dose antibiotics (6-12 months), e. g. furantoin
100 mg daily, trimethoprim 100 mg twice daily, co-trimoxazol
one tablet (480 mg) one or twice daily
Immunotherapy ( e.g. Uro-Vaxom® )
In women, whose infections are precipitated by sexual
intercourse, voiding and single dose of antibiotics after
intercourse may be prevent infection developing
Chronic and recurrent bacterial
cystitis cont. …
Abacterial cystitis
Trauma, toxic drugs (e. g. severe haemorrhagic
cystitis is caused by cyclofosfamid), chemicals,
irradiation, viruses and related organism such as
chlamydia trachomatis
Interstitial cystitis
Special type of chronic abacterial cystitis. Well
recognise syndrome of unknown aetiology.
Diagnosis and treatment are very complicated.
ASYMPTOMATIC BACTERIURIA
1-2 % schoolgirls, 3-5% of adult women, 0.5%
schoolboy, 0.5% of adult male
Management
Exclude some abnormalities of the urinary tract
Active treatment –pregnant woman due to 30% risk
of developing acute pyelonephritis
Other treatment is doubtful
URINARY TRACT INFECTION
IN CHILDREN
Two special problems:
1. Symptoms of urinary infection in small children may be
non-specific
2. Collection of urine, particularly in small girls, may be
difficult
By coincidence UTI a anomalies of urinary tract -3
groups of children with UTI:
1. Anomalies, which can be lead to rapid deterioration in
renal function -reflux, obstruction
2. Relatively harmless anomalies -duplication of upper tract,
bladder anomalies
3. Normal urinary tract