URINARY TRACT

INFECTION

Definitions

UTI : Inflammatory response of urothelium to bacterial invasion associated with bacteriuria &

Pyuria.

Bacteriuria: Presence of bacteria in urine which is normally free of bacteria.It may be due to contamination.

Pyuria: Presence of WBCs in urine.

Bacteriuria without pyuria: Colonization with no infection.

Pyuria without bacteriuria: T.B, stones, cancer.

Uncomplicated UTI: Inf. in normal U.T both structurally & functionally.

Complicated UTI: U.T is functionally or structurally

abnormal, host is compromised, increased virule-

nce of bacteria (pregnancy, elderly, DM, instrume-

ntation).

First or isolated: Never had inf. before or since a

long time.

Unresolved inf.: not responded to antimicrobials.

Recurrent inf.: occur after successful resolution of inf.

Incidence & Epidemiology

-UTIs are the most common bacterial inf.

-1.2% of office visits by females & 0.6% by males.

-50% of females will experience UTI during life.

-Once a pt. has inf., is likely to develop subseque-

nt infections.

Pathogenesis:

Routes of infection:

1-Ascending route:

-Bowel reservoir----urethra----bladder

e.g: perineum soiled with faeces.

indwelling catheter

-Cystitis may ascend to kidney by VUR.

2-Haematogenous route:

-Renal infection with staph. from a septic focus.

3-Lymphatic route:

-Not common.

-From adjacent organs (severe bowel inf. – RP abscess).

Urinary Pathogens:

E. Coli : 85% of community acquired

50% of hospital acquired

Proteus, klebsiella, gm +ve (E. faecalis): remain.

Bacterial adherence:

Bacterial adhesins:

-UP expresses a number of adhesins that allow it

to attach to U.T tissues.

Natural defenses of U.T:

1- Periurethral & urethral region:

- Normal flora of introitus & urethra contain orga-

- nisms as lactobacilli & streptococci forming a

- barrier against UP.

- - Flow of urine.

2- Urine:

- Organisms normally colonizing the urethra do

not multiply in urine.

- Bacterial growth is inh. by dilute urine or high osmolality assoc. with low PH.

- Tamm-Horsfall ptn. (1000ng/ml) block bacterial

binding to urothelial receptors.

3- bladder emptying.

4- General immunity.

Diagnosis

- -Urine & U.T are normally free of bacteria & infl.

Urine collection:

-Mid stream.

-How to collect ?

voided or catheterized

Suprapubic aspiration: highly accurate,

useful in newborn

pts who can not void

-Non circumcised: prepuce retracted, glans washed

-In females: spread labia, wash introitus, mid str.

Urine analysis:

5-10 ml centrifuged for 5 min. at 2000 rpm.

Bacteriuria found in 90% of infs. with counts

>100000 CFU/ml.

2 WBCs/HPF in centrifuged specimen= 10 in an

unspined specimen & both correlates with bacte-

ruria.

Imaging techniques:

-Not required in most cases.

-Indications: fever- failure to respond to treatment

recurrent infs.- D.M- history of stones or surgery.

-Plain, IVU, VCUG, U/S, CT.

Principles of antimicrobial treatment:

-Efficacy is dependent on drug level in urine &

duration this level remains above MIC of inf.

organism.

-Concentration in blood is not important as in

urine, except in septicemia or bacterimia.

-Patients with renal failure:

Dose modification are necessary for drug cleared

only by kidneys.

Conc. power is impaired ---difficult eradication of

infection.

Bladder infections

Uncomplicated cystitis:

-Most caes in females.

-25% between 20-40 yrs.

Risk factors:

-Weak urine flow.

-Promote colonization: sexual activity.

-Facilitate ascent: catheter, fecal incontinence.

Clinical presentation:

-Burning, frequency, urgency, S.P pain.

-Haematuria, foul smelling urine.

-Fever & chills usually absent (superficial mucosal infection).

Causative organism: E. coli 80-90%

Lab diagnosis:

-urine analysis: pyuria, bacteriuria, hematuria.

-urine culture: often not necessary.

Treatment:

-TMP-SMX, quinolones, floroquinolones

-Duration: 3 days.

Complicated cystitis:

-Occur in compromised U.T or by resistant org.

-mild cystitis----life threatening renal inf. & urosepsis.

-Urine culture is mandatory.

-treatment of cause.

Kidney Infections

Acute Pyelonephritis:

-Inflammation of both renal parenchyma & pelvis.

Causative organism:

-E. coli (80%), proteus, klebsiella, pseudomonas

-Rarely, gm +ve.

Pathology:

-Renal enlargement, capsule strips easily, small

yellowish white cortical abscesses with parench-

ymal hyperemia.

-Glomeruli usually spared, neutrophil infiltrate.

Clinical picture:

-Chills, fever (100F or >), flank pain.

-LUTS (dysuria, urgency, frequency).

-GIT symptoms.

Lab diagnosis:

-CBC: leucocytosis with predominance of

neutrophils, inc.ESR & C- reactive ptn.

U.A: WBCs in clumps, bacterial rods.

WBC casts

Specific casts (bacteria in ptn matrix).

U.C:

Blood culture:

Radiology:

IVU: renal enlargement (1.5 cm greater in length).

focal ― (focal bacterial nephritis)

disappear with treatment.

calyceal & ureteral dilatation (endotoxins)

U/S & CT: to diagnose complicated PN

to reevaluate pts not responding after

72 hours treatment.

Treatment: Antibiotics for 7 days.

Bed rest – antipyretics.

Hospitalize or not ?

Emphysematous PN:

-Acute necrotising parenchymal & perirenal infn.

caused by gas forming UP.

-Organism cause fermentation of glucose ----CO2.

-However, not common in diabetics.

Should be considered compl. of severe PN.

-Mortality rate 20-40%

Causative organism:

-E. coli (commonest), klebsiella, proteus.

Clinical picture:

-Triad of fever, vomiting, flank pain.

-Pneumaturia, when infn. involves collecting system.

Imaging:

-Plain KUB: crescentic gas shaddow (in renal

space) & loculated ― ― (in parench.)

-IVU: rare of value (NF or poorly functioning K.)

U/S: gas.

CT: procedure of choice.

Treatment: surgical emergency

-Fluid resuscitation & broad spectrum antibiotics.

-Nephrectomy if no improvement after few days.

Can be deferred if condition improved.

Renal Abscess:

-Collection of purulent material confined to renal

parenchyma.

-Usually due to VUR in an obstructed kidney.

-Causative organism: g +Ve or –Ve.

Clinical picture:

-Triad------cystitis

-History of g +Ve source of inf.(1-8 weeks) before

onset of symptoms. e.g: skin carbuncle.

Lab diagnosis:

-Leucocytosis, pyuria, bacteriuria (if communicat).

-Urine culture: no or different organism (bld borne).

Radiology:

-Renal enlargement & distortion of renal contour.

-Renal fixation on insp. & exp. films.

-Obliteration of psoas shadow & scoliosis.

-CT is the procedure of choice

Renal enlargement & area of low attenuation.

Thickening of perinephric fascia.

Treatment:

-PC or open drainage (DD. Renal tumor).

-I.V antibiotics & observation, if <3cm.-----good response.

-Follow up with U/S or CT till complete resolution.

Infected Hydronephrosis & Pyonephrosis:

Infected HN: bacterial inf. in a hydronephrotic k.

Pyonephrosis:inf. HN associated with suppuration

of renal parenchyma----partial or total loss of renal function.

Differentiation not always easy.

Clinical picture:

-Triad.

-Bacteria may not be present if ureter completely

obstructed.

Radiology: internal ecchoes in dilated P.C system.

Treatment: drainage &antibiotics.

Perinephric abscess:

Etiology:

-Rupture of a cortical abscess into perinephric sp.

-Infected perirenal hematoma or urinoma.

-Spread of osteomyelitis from T.B lumbar spine.

When it rupture through renal fascia ---paraneph.

abscess.

Clinical picture: insidious onset, 1/3 afebrile.

Local signs of infl. (hotness, redness, oedema,

loin mass may be pointing)

No response to antibiotics.

Radiology:

-Absent psoas shaddow, elevated or immobile

diaphram.

-U/S & CT: ecchogenic collection.

Treatment:

-Surgical drainage (if large)

-PC ― (if small)

PROSTATITIS

Etiology:

1- G –Ve: E. coli (80%), kleb., pseudomonas,….

2- G +Ve: staph aureus (5-10%)

3- Chlamydia & U. urealyticum: minor role.

Risk factors:

1- Intra-prostatic ductal reflux.

2- Immunologic alteration inside prostate.

3- Acute epididymitis, indwelling catheter, TURP

especially with infected urine.

Pathology:

-Increase no. of infl. cells within parenchyma.

-Lymphocytic infil. in stroma adjacent to acini

(most common pattern).

-Corpora amylacea (deposition of pr. secretion

around a sloughed epithelial cell) may obstruct

pr. gland.

Classification: ―Traditional classification system‖

Type s. of UTI bacteria infl. cells

1-ABP: severe + +

2-CBP: mild + +

3-NBP: ----- - +

4-Prostatodynia: ----- - -

Clinical picture:

1- ABP: fever, severe irritative & obstructive C/O.

5%------- CBP

2- CBP: asymptomatic

irritative & obstructive C/O

3- NBP: pain (predominant C/O) in perineum,S.P,

penis, testis, low back.

4- Prostatodynia: painful ejaculation (50%)

symptoms tend to wane & wax over time

1/3 improve over one year.

Diagnosis:

1- Physical examination:

-Important but not helpful for diagnosis or classificat

ABP: prostate is hot, boggy, very tender

Other types: prostate is normal.

2- Cytology & culture:

- Stamey 4 glass urine collection

Treatment:

1- Antibiotics: for ABP & CBP.

2- Alpha adr. blockers: for NBP & prostatodynia

with poor relaxation of B.N -----increase ur. flow &

decrease IPR.

3- Anti-inflammatory:

NSAIDs- cortisone.

4- Ms. relaxants:

NBP & prostatodynia may be due to smooth & skeletal ms dysregulation of pelvis

& perineum.

5- Phytotherapy:

Some plant extracts show 5 alpha- reductase

activity, alpha blocker, anti- inflammatory.

6- Allopurinol:

IPR---inc. metabolites containing purine & pyrimidine in pr. ducts-----inflammation.

Orchitis:

Definition:

-Inflammation of testis, & also describe testicular

pain without evidence of infl.

Etiology:

-Isolated orchitis is relatively rare & usually viral

due to blood spread.

-Orchitis of bacterial origin usually occur due to

local spread from ipsi. epididymis (E. coli, pseud.,

Staph, strept.,N. gonorrhea).

Presentation:

-Pain- fever- nausea & vomiting- tenderness- secondary hydrocele (mild).

Diagnosis:

Urine analysis- urethral swab

U/S: to rule out malignancy & torsion

Treatment:

- Rest- scrotal support- hydration- antipyretics- AI

- Antibiotics.

Chronic orchitis:

-Inflammation & pain in testis, without swelling

for >6 weeks.

-Self limited & may take years to resolve.

Epididymitis:

-Acute : sudden pain, swelling.

-Chronic: pain & infl. with no swelling >6 weeks.

may be due to inadequate treatment.

-Spread from bladder, urethra & prostate.

-Starts in tail-----body-----head.

-Testis is involved in most cases-----epididymo-orchitis.

Treatment:

-antibiotics for 4-6 weeks.

-Chronic: self-limiting taking long duration.

-Epididymectomy: with treatment failure & to cure

pain.

Tuberculosis (T.B)

-Always considered in a pt. with vague long

standing urinary C/O with no obvious cause.

-Age: 20-40 yrs, uncommon in children.

When to suspect?

-Following presentation without obvious etiology.

Frequency—recurrent cystitis not responding to

treatment---gross or microscopic hematuria---

sterile pyuria.

T.B of kidney:

-Organism settle in blood v. close to glomeruli.

-Caseating granulomas develop & consist of giant

cells (Langhans) surrounded by lymphocytes &

fibroblasts.

-Caseous material open through calyces---cavities

of moth-eaten appearance.

-Course depends on virulence & resistance.

-If pathology progress + obst.---autonephrectomy.

-If healing occur---fibrosis & calcification---stricture

in calyces or PUJ.

-Mycobacterium may remain viable in calcific lesions.

Calcification

No upper calyx

Stricture & hydronephrosis

Hydronephrosis

T.B of ureter:

-T.B ureteritis---fibrosis---str. usually at UVJ

-Whole ureter may be affected---multiple levels

ureteric stricture.

T.B of bladder:

-Starts around U.O---infl. & edema---T.B granuloma

-T.B ulcers is rare, occasionally whole bladder is

covered by infl. velvety granulation---bladder fibr-

osis & contraction.

KUB, stricture, hydronephrosis

T.B of epididymis & testis:

-Painful & infl. scrotal swelling. D.D: ep.orchitis.

-Globus minor affected alone in 40%.

-Testicular affection without ep. is very rare.

-Scrotal sinus.

T.B of penis----superficial glanular ulcer. D.D:Tr.

T.B of urethra ---urethral stricture.

Diagnosis:

1-Tuberculin test:

-M.T.B complex (M.T.B—M. bovis—M. microti—M.

africanum).

-Intradermal inj. of a PPD of tuberculin.

-Infl. condition reaching max.between 48-72 hrs.

-Central indurated zone surrounded by erythema.

-+Ve reaction =inf., but not indication of active

T.B or C/O due to T.B.

2-Urine examination:

-Sterile pyuria-2ry inf.(20%)-microhematuria(50%)

3-Urine culture:

-Lowenstein-Jensen.

-Takes 6-8 weeks (slowly growing).

-3-5 consequetive early morning samples

(org. is intermittently excreted).

4-Imaging:

-Plain KUB:

-Calcification in kidney, ureter, bladder, seminal

vesicle.

-Plain chest & spine.

-IVU:

-Fibrosed & occluded calyx (lost calyx).

-Moth-eaten cavities, HUN, contracted bladder.

Treatment

First line drugs:

1-Isoniazid (INH): hepatotoxicity, peripheral neuritis.

5 mg/kg maximum 300 mg

2-Rifampicin: hepatotoxicity

10 mg/kg max. 600 mg

3-Pyrazinamide: hepatotoxicity

20-25 mg/kg

4-Streptomycin: ototoxicity

5-Ethambutol: retrobulbar neuritis

15-25 mg/kg

Cornerstone is multidrug treatment to decrease

duration of treatment & drug resistant developm-

ent.

Second line drugs:

-kanamycin—amikacin—ciprofloxacin……

Guidelines:

-Short course 6 months regimen.

-All drugs given in a single dose.

-Followup with urine culture at 3, 6, 12 months

after treatment finished.

Surgery: delayed until medical treatment adminis- tered for 4-6 weeks.

Parasitic diseases

Urinary schistosomiasis:

Caused by S. haematobium.

Pathology & pathogenesis:

-Worms in pelvic v. plexus----eggs in lower UT.

-Granulomas formed in response to egg Ag------

large,bulky, hyperemic polypoid masses. As egg

laying ceases, eggs are destroyed or calcified &

infl. wanes & replaced by f.t. (inactive form). Acute

& chronic bladder ulcers

-Obstructive uropathy occur due to chronic dis.

Usually bilateral asymmetrical (JV & lower ureter)

-Bladder cancer is a sequalae:early, sq.c.c (60-90%).

Presentation:

Acute:‖ Katayama fever‖

-fever, lymphadenopathy, splenomegaly, urticaria

-occur 3-9 weeks after inf.

-terminal hematuria & burning.

Chronic:

-HUN—contracted bladder

Diagnosis:

1-Presence of eggs with terminal spikes is diagn-

ostic of & only possible during active inf.

2-Serologic tests: do not diff. between acute & ch

inf.

3-Plain & IVU.

Treatment:

Medical:

Praziquentel: drug of choice

cure rate 80-100%

dose:2 oral doses of 40mg/kg in 24 hrs

No serious side effects.

Surgical: nephrectomy—ureteric implantation

Filariasis

Lymphatic filariasis:

-Causative organism: W. bancrofti

-Cycle proceeds from human---mosquito---human.

-Acute lymphatic infiltration----fever, lymphangitis &

lymphadenitis---chronic lymphatic obstruction

& dilation----hydrocele, elephantiasis of limbs &

chyluria.

-Diagnosis: C.p & Giemsa stain for blood.

-Treatment:

Diethylcarbamazine (DEC), ivermectin, albendazole.

Nonlymphatic Filariasis:

-Transmitted by black flies (Simulum species).

-Adult worms inhibit S.C tissues----f. nodules in which it is encapsulated.

-Microfilaria travel through dermis & eye ----------blindness.

-Diagnosis:

Microscopic exam. of skin snips under normal saline or Giemsa stain.

Treatment:

-Ivermectin. DEC not used due to severe allergic

immune response to microfilaria dying in skin.