Urological Infections

Question 1

Examples of urological infections

Answer 1

-Urinary Infection
=Cystitis
=Recurrent UTIs
=Pyelonephritis
=Prostatitis
=Epididymo-orchitis
=Balanitis

-Urosepsis
-Fournier’s gangrene / necrotising fasciitis

Question 2

Definition and incidence of UTI

Answer 2

-Inflammatory response of urothelium to bacterial invasion
-Constellation of symptoms (pain, frequency, dysuria, haematuria)
-Typically defined as >103-5 cfu/ml and symptoms

-Incidence:
=Common
=Prevalence – 4% reproductive females; 20-30% Elderly women
-Sex/Gender :
=Lower prevalence in men- <1% adults, 10% elderly men

Question 3

Presentation of urological infections

Answer 3

-Bladder infection – Cystitis – suprapubic pain, frequency, dysuria, haematuria, malodorous urine
-Kidney infection – Pyelonephritis – Loin pain, fevers, haematuria, sepsis
-Prostate infection – Acute Prostatitis – perineal pain, pain on ejaculation, tender prostate on DRE, fevers, systemically unwell
-Epididymal/Testicular infection - Epididymitis/Orchitis – testicular/scrotal pain, swelling, fevers
-Urethral infection – Urethritis – dysuria, urethral discharge, and/or pruritis

Question 4

What is a complicated UTI?

Answer 4

-Infection associated with factors increasing colonization and decreasing efficacy of therapy. Requires one or all of following:
=Anatomic or functional abnormality of urinary tract (enlarged prostate, stone disease, diverticulum, neurogenic bladder, etc.)
=Immunocompromised host
=Multi-drug resistant bacteria

Question 5

UTI Risk Factors and Mechanism

Answer 5

-Reduced Urinary Flow:
=BOO with incomplete bladder emptying (BPH, urethral stricture)
=Neuropathic bladder – MS, DM, Sp cord injury
=Poor fluid uptake – CVA, MS, MND, Sp cord injury

-Increased Colonisation:
=Sexual activity – increased innoculation
=Spermicide
=Oestrogen depletion/post-menopause
=Antibiotics – altered flora* Renal Tract Stones – may be caused by bacteria (struvite/MAP)… or subsequently colonised by bacteria

-Retrograde Infection/Ascent
=VUR
=Catheterisation
=Ureteric stent
=Urinary incontinence
=CUR

-General Immunosuppression
=DM, Elderly, CKD, HIV, Pregnancy
=Drugs – steroids, transplant

-General Mechanism: Ascending infection (see causes above)
=Haematogenous spread – v rare (Staph aureus from distant abscess/infection), candida fungaemia, TB

Question 6

UTI: Causative Organisms

Answer 6

-Community Acquired UTI (from bowel flora)
=E coli (UPEC- Uropathogenic E coli)
=Proteus
=Klebsiella
=Staph saprophyticu
= E faecalis / Strep faecalis

-Nosocomial
=E coli
=Klebsiella
=Enterobacter
=Citrobacter
=Serratia
=Ps aeruginosa
=Providencia
=Staph saprophyticus
=E faecalis / Strep faecalis

-ISC/LTC
=Gardenella
=Mycoplasma
=Ureaplasma urealyticum

Question 7

UTI Investigation

Answer 7

-All patients
=Focussed Hx, O/E
=MSU – UA: RBC, WCC, Nitrites
=MSU – Urine Culture, send culture if aged >65, haematuria for women, all for men
=DRE

-Consider:
=FBC, U&E
=Blood Cultures
=Imaging – complex UTIs – CT, Renal USS
=Flow Test & Bladder Scan - PVR
=Cystoscopy – recurrent UTIs, complex UTIs, ongoing haematuria

Question 8

Management of UTI

Answer 8

-The type and duration of antibiotic treatment is dependent on site of infection (if known), host factors and severity of illness.
=Most antibiotics are highly concentrated in the urine and therefore are very effective at clearing bacteria from the urinary tract.

-Highest mean urine concentration (from highest to lowest):
=Cabrenicillin > Cephalexin > Ampicillin > TMP/SMX > Cipro > Nitrofurantoin

-However, in cases of pyelonephritis, prostatitis or epididymitis, proper tissue antibiotic concentrations are important

Question 9

Management of uncomplicated UTI

Answer 9

-Trimethoprim 200mg bd for 3-5d
-Nitrofuratoin 100 mg BID x 5 days or a 3 day course of oral. 7 days for men
trimethoprim/sulfamethoxazole (TMP/SMX) is 95% effective
-If TMP/SMX resistance is > 10 – 20% (U.S. West coast, Europe), consider fluoroquinolones

Question 10

Management of complicated UTI (acute pyelonephritis)

Answer 10

-Patients who are candidates for outpatient therapy may utilize:
-Oral ciprofloxacin 500 mg BID x 7 days
-Oral TMP-SMX DS BID x 14 days (not for Enterococcus or Pseudomonas)
-Use of initial one-time IV agent (ceftriaxone 1 g, amimoglycoside, fluoroquinolone)
-Adjust antibiotics according to culture results

Add appropriate drainage for intrarenal, perirenal or pararenal abscess

Question 11

Inpatient UTI management

Answer 11

-IV Gentamicin + Amoxicillin
-IV fluoroquinolone (eg Ciprofloxacin)
-3rd generation cephalosporin (eg Cefotaxime, Ceftraixone)
-Extended spectrum penicillin (eg Peperacillin + Tazobactam = Tazosin)
-Carbapenem
-Blood cultures positive in 20 – 40% of patients
-Consider Switch from parenteral to oral therapy at 48 hours after clinically well
-Treat for 14 days.

Question 12

Overview of pyonephrosis

Answer 12

Pyonephrosis is a kidney obstruction caused by infection and the formation of pus (“pyon” in Greek), which can result in rapid and complete loss of kidney function. Because the pus is thicker than urine, it blocks the passage of urine and results in the formation of an abscess. Although the condition is rare, it has been reported in adults, children, and even new-borns

Urine obstruction and hydronephrosis

-I: USS, CT, urinalysis

-M: IV abx, drainage

Question 13

Management of Fournier’s Necrotising Fasciitis/ gangrene

Answer 13

-Aggressive Rx with Abx cover for Gm+, Gm-, Anaerobes: eg Amoxicillin + Gentamicin + Metronidazole
-Immediate recognition + Immediate aggressive Surgical debridement (necrectomy)

Question 14

Management of epididymitis

Answer 14

Fluoroquinolones (Ofloxacin) or TMP/SMX for at least 2 weeks to obtain adequate tissue levels

Question 15

Management of urethritis

Answer 15

Combination of Ciprofloxacin + Doxyxycline for 2 weeks
-Or Ofloxacin for 2 weeks

Question 16

Management of acute bacterial prostatitis

Answer 16

Fluoroquinolones (Ofloxacin) or TMP/SMX for 2-4 weeks to obtain adequate tissue levels

Question 17

Management of re-infection UTI

Answer 17

A test of cure should be undertaken by repeat culture in pregnancy, pyelonephritis, and complicated or relapsing UTI.

Question 18

Management of relapsing infection

Answer 18

Failure to clear or completely eradicate the pathogen despite a reasonable treatment course should trigger a urologic investigation that includes imaging to define possible anatomical causes and prolonged therapy in the meantime

Question 19

Management of asymptomatic bacteriuria

Answer 19

Generally, does not require treatment, except in pregnancy.
-Treatment is not indicated in the elderly (20-40% incidence) and patients with LTC (90-100% colonisation)

Question 20

Principles of antibiotic prescribing

Answer 20

-In general, Abx choices for Rx simple UTIs is dependent on local guidelines, based on regional Abx resistance patterns
-Trimethoprim and Nitrofurantoin are used with Caution with CKD – not effective with advanced CKD
-Trimethoprim may increase K+ and Creat
-Gentamicin is nephrotoxic (and ototoxic) – use if required with dose adjusted for renal function

-Trimethoprim: effective against most uropathogens except Enterococcus, Pseud
-Nitrofurantoin: effective against most uropathogens except Pseud, Proteus
-Penicillins: effective against Gm +ve & some Gm –ve, may require β-lactamase inhibitor (clavulinic acid: co-amoxiclav;Tazobactam: Tazosin (piperacillin + tazobactam))
-Quinolones (Ciprofloxacin, Ofloxacin): effective against Gm –ve & some Gm +ve, including Proteus
-Aminoglycosides (Gentamicin): effective against Gm –ve, (some Gm+ve)
-Nitroimidazole (Metronidazole): effective against Anerobe
- Vancomycin: effective against Gm +ve

Question 21

Overview of urethritis

Answer 21

-Definition: urethral infection caused by Neisseria gonorrhoeae (GU) or Chlamydia trachomatis (NGU)

-Presentation: Classically STI with urethral discharge after unprotected sex: dyuria + urethral discharge +/- pruritis
=GU: purulent discharge (white – yellow – green)
=NGU: mucoid or clear. (Generally less copious & severe than GU)

-Complications:
=Urethral stricture, orchitis, infertility, testicular atrophy
=Untreated gonococcal urethritis may disseminate → arthritis, meningitis, endocarditis.
=Untreated non-gonococcal urethritis may → reactive arthritis or infertility.

-Rx: various regimens-
=IM Ceftriaxone plus Azithromycin as a first-line regimen, preferably given together under direct observation
=Ofloxacin + Doxycyxlin
= Consult local guidelines

Question 22

Overview of Fournier’s Gangrene/ Necrotising Fasciitis

Answer 22

-Definition: gangrene / necrotising fasciitis of the genitalia; typically with synergistic (mixed aerobic and anaerobic) infection – Urological Emergency

-Presentation: pain, sepsis, cellulitis with evidence of necrosis of the genitalia

-RFs:
=Elderly age, DM, obesity, immuno-suppression, previous genital injury/infection, recent genital/scrotal surgery (circumcision)
=If untreated or not Rx early → rapidly swelling necrotising fasciitis involving perineum, abdwall → death

-Rx:
=Resuscitate: ABC, Blood Cultures, IV Abx (IV Gent + Amox + Metronidazole) + IVF
=Emergency Surgery: Scrotal exploration, debridement, possible orchidectomy, may involve massive resection of necrotic tissue (necrectomy) including degloving of penis, removal of scrotum, debridement of skin and fascia over entire perineum, peri-anal, inguinal, lower abd,upper abd… thorax
=May require Incapacity consent
=May require joint surgery with colorectal surgeons
= Subsequent reconstructive plastic surgery (myocutaneous flaps)

Question 23

Overview of prostatitis

Answer 23

-Acute bacterial vs chronic (bacterial, pelvic pain syndrome)

-P: acute bacterial (fever, myalgia, nausea, fatigue, sepsis), chronic (pelvic pain, LUT symptoms, sexual dysfunction, pain with bowel movements, tender and enlarged prostate

-I: dipstick, MCS, NAAT

-M: acute bacterial (admission, ciprofloxacin or trimethoprim for 2-4 weeks, analgesia, laxatives for pain during bowel movements), chronic (Tamsulosin, analgesia, psychological, abx trimethoprim or doxy for 4-6 wees, laxatives)

Question 24

Overview of balanitis

Answer 24

Balanitis is common in young boys with a non-retractile foreskin and in the elderly where there may be predisposing factors such as malignancy or diabetes. The organisms most commonly involved are faecal bacteria and candida.

Presentation is with irritation or pain in the penis and discharge from beneath the foreskin. Inflammation is visible. Recurrent balanitis may cause a phimosis with disturbance of micturition.

-Balanitis: inflammation of glans penis/ posthitis: inflammation of foreskin

Question 25

Treatment for balanitis

Answer 25

-Treatment depends on the cause
anyone with balanitis should be advised to (1): avoid contact with any potential skin irritants (e.g. soap), keep area clean by bathing twice daily with a weak saline solution while symptoms persist
-In consideration of men with acute balanitis
refer all men with acute balanitis and suspected urethritis, ulceration, or lymphadenopathy to a genito-urinary medicine clinic (2) with the exception of recurrent ulceration due to herpes simplex in someone with an established diagnosis
-Swab the sub-preputial space prior to starting empirical treatment (2)
-Balanitis secondary to candida responds to topical antifungal cream or oral antifungal treatment
in adults, treatment options include:
=topical imidazole e.g. econazole, ketoconazole, sulconazole,clotrimazole 1% or miconazole 2% applied twice a day till the symptoms resolve
=oral fluconazole - 150mg stat if symptoms are severe
=topical nystatin - in case of resistance and allergy to imidazole (3)
=topical terbinafine
-in children, treatment options include
=a topical imidazole e.g. clotrimazole, econazole, ketoconazole, miconazole, =sulconazole
=topical nystatin
=recommended that treatment with a topical antifungal should be continued for 2-3 days after clinical cure

-bacterial balanitis may require oral antibiotic treatment (e.g. flucloxacillin or erythromycin)
sometimes a combined steroid/antibiotic cream (e.g. hydrocortisone acetate 1%, fusidic acid 1%) or combined antifungal/steroid cream (e.g. hydrocortisone 1%, clotrimazole1%) is used to reduce inflammation caused by infection
=topical corticosteroid should be applied until the inflammation has cleared
twice a day for up to 2 weeks (3)

-Referral for consideration for circumcision may be necessary once the inflammation has settled.

-Older patients should be tested for diabetes.