URINARY TRACT INFECTION ( UTI )
Defenition :- Significant bacteriuria in presence of symptoms ( bacteriuria= bacteria in urine )
(i.e Urine is normally sterile and they are several things make urine sterile :- the urethral sphincter,Length of urethra,Frequant washing,Valves and acidty of urine)
Terminology :-
Pyelonephritis = Inflamition of the Kidney.
Uretitis = Inflamition of the Ureter.
Cystitis = Inflamition of the bladder.
Urethritis = Inflamition of the Urethra.
Etiology:- The bacteria most often seen in UTI are fecal origin.
These organisms are a subset of the organisms found in the feces.
classifications according to mode of transmission :-
1) Community-acquired UTI:-
a) Uncomplicated UTI (patients with normal anatomic structure and function )
More than 90% of acute UTIs are caused by certain strains of E.coli
10 to 20 %are caused by S.saprophyticus
5% or less are caused by Enterobacteriaceae organism or enterococci
b) In complicated cases of UTI ( anatomic obstructions or from catheterization )
Themost common causes are E.coli, K.pneumoniae, Proteus mirabilis, Enterococcus spp. and Pseudomonas aeruginosa
c) In Rare Cases:-
Candida albicans can cause UTI (ex. diabetic patients)
Strict anaerobic bacteria.
2) Hospital-acquired UTI :-
a) UTI nosocomial acquired infectio (40%)
b) Enterococcus most common cause of nosocomial UTI
c) 80% are related to the use of a urethral catheter.
d) The remaining cases are associated with other urinary tract instrumentation or surgery.
f) The duration of catheter is very important is classified as a short term( <30 days )or long term ( >30 days )
Short term:- Usually single microorganism E.coli, Pseudomonas aeruginosa, Klebsiella spp. , Proteus spp. and S.epidermidis
Long term:- Usually polymicrobial Provedencia stuartii Pseudomonas spp. and E.coli
Epidemiology:-
The majority of the cases seen in the doctor's office are in women
40% of all women have at least one episode of a UTI at some time in their lives
Males experience a rapid increase in the incidence of UTI's in their 40s
Risk factors:-
a) Abnormality of the urinary tracts that obstruct slow the flow of urine (e.g. stone, an enlarged prostste gland etc.)
b) Catheters, or a tube placed in the bladder is most common sources of infection.
c) Infants with congenital abnormalities( in a small percentage)
d) Immunosuppressed patients.
e) Women who use diaphragm or spermicides.
f ) Patients with a Neurogenic bladder or bladder diverticulum.
g) Postmenopausal women with bladder or uterine prolapse.
h) pregnant women.
Pthogenesis:-
a) Routes of infection:- Bcteria may cause UTIs by four possible routes ascending ( from colon ), Hematogenous, lymphatic or
direct spread (e.g. surgery )
b) Host factors:- important inprtection include the normal flow of urine and epithelial cells lining the urinary tract.
c) Bacterial factors:- Attachment and invasion
Resistance to seru baceriocidal activity and phgocytosis,presence of K antigen and hemolysin productin( e.g E.coli)
(i.e Urine is normally sterile and they are several things make urine sterile :- the urethral sphincter,Length of urethra,Frequant washing,Valves and acidty of urine)
Terminology :-
Pyelonephritis = Inflamition of the Kidney.
Uretitis = Inflamition of the Ureter.
Cystitis = Inflamition of the bladder.
Urethritis = Inflamition of the Urethra.
Etiology:- The bacteria most often seen in UTI are fecal origin.
These organisms are a subset of the organisms found in the feces.
classifications according to mode of transmission :-
1) Community-acquired UTI:-
a) Uncomplicated UTI (patients with normal anatomic structure and function )
More than 90% of acute UTIs are caused by certain strains of E.coli
10 to 20 %are caused by S.saprophyticus
5% or less are caused by Enterobacteriaceae organism or enterococci
b) In complicated cases of UTI ( anatomic obstructions or from catheterization )
Themost common causes are E.coli, K.pneumoniae, Proteus mirabilis, Enterococcus spp. and Pseudomonas aeruginosa
c) In Rare Cases:-
Candida albicans can cause UTI (ex. diabetic patients)
Strict anaerobic bacteria.
2) Hospital-acquired UTI :-
a) UTI nosocomial acquired infectio (40%)
b) Enterococcus most common cause of nosocomial UTI
c) 80% are related to the use of a urethral catheter.
d) The remaining cases are associated with other urinary tract instrumentation or surgery.
f) The duration of catheter is very important is classified as a short term( <30 days )or long term ( >30 days )
Short term:- Usually single microorganism E.coli, Pseudomonas aeruginosa, Klebsiella spp. , Proteus spp. and S.epidermidis
Long term:- Usually polymicrobial Provedencia stuartii Pseudomonas spp. and E.coli
Epidemiology:-
The majority of the cases seen in the doctor's office are in women
40% of all women have at least one episode of a UTI at some time in their lives
Males experience a rapid increase in the incidence of UTI's in their 40s
Risk factors:-
a) Abnormality of the urinary tracts that obstruct slow the flow of urine (e.g. stone, an enlarged prostste gland etc.)
b) Catheters, or a tube placed in the bladder is most common sources of infection.
c) Infants with congenital abnormalities( in a small percentage)
d) Immunosuppressed patients.
e) Women who use diaphragm or spermicides.
f ) Patients with a Neurogenic bladder or bladder diverticulum.
g) Postmenopausal women with bladder or uterine prolapse.
h) pregnant women.
Pthogenesis:-
a) Routes of infection:- Bcteria may cause UTIs by four possible routes ascending ( from colon ), Hematogenous, lymphatic or
direct spread (e.g. surgery )
b) Host factors:- important inprtection include the normal flow of urine and epithelial cells lining the urinary tract.
c) Bacterial factors:- Attachment and invasion
Resistance to seru baceriocidal activity and phgocytosis,presence of K antigen and hemolysin productin( e.g E.coli)
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