Urinary Tract Infections.ppt
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Urinary Tract Infections
UTI
? UTI - common affliction for which patients seek medical attention
? UTI can occur from infancy through old age
? more common in females than males
~20% of all females will experience a UTI during
their lifetime
UTI
Definitions
The term "UTI" represents a wide range of clinical syndromes
Bacteriuria: the presence of bacteria in urine
- does not necessarily imply infection
? Asymptomatic bacteriuria: presence of bacteria in the urinary tract in the absence of symptoms
- clinical significance controversial outside certain patient populations
- pregnant women
- patients undergoing invasive procedures
of the urinary tract
UTI
Definitions
? Cystitis: UTI presumed to be confined to the bladder
- painful/burning urination
- urgency or frequency
- absence of symptoms or physical signs suggesting
inflammation at other sites within the urinary tract
? Note: clinical criteria are notoriously inaccurate in identifying the actual anatomic site of infection
UTI
Definitions
? Pyelonephritis: clinical diagnosis which implies a more invasive infection
- inflammation of the kidney and renal pelvis is assumed to be present when patients have pain or tenderness involving the flank, together with other clinical or laboratory evidence of UTI
-fever, nausea, chills, malaise, headache, etc
UTI
Definitions
? Prostatitis: inflammation / infection of the prostate gland
- may present as acute or chronic
? Intrarenal abscess / perinephric abscess: collection of pus in the kidney or in the soft tissue surrounding the kidney
UTI
Definitions
? Complicated infections
- underlying abnormality that predisposes patient to UTI
or makes UTI more difficult to treat effectively
? Recurrent Infections
Relapse - recurrence of infection by same organism after discontinuation of treatment
Reinfection - recurrence of infection by a different organism after discontinuation of treatment
UTI
Pathogenesis
? UTI usually due to patients own intestinal flora
- ascending route of infection
- organisms enter the urinary tract in a retrograde fashion via the urethra
? Complicating factors such as catheters, nephrostomy tubes, surgery, urinary stones, etc
- allow organisms to enter and persist in urinary tract
- alter the typical spectrum of organisms
- may have multiple etiologies
UTI
Pathogenesis
? Elderly patients
- incontinant
- functionally impaired
- postmenopausal changes
- neurological alterations
? Pregnant women
- altered anatomy
? Hematogenous route
- endocarditis, bacteremias, tuberculosis
- disseminated infections
UTI
Etiology
? Majority of UTI are due to a single pathogen
? The Enterobacteriaceae responsible for 90% of all UTI
- gram negative bacilli
- facultatively anaerobic
- common intestinal flora
? Escherichia coli most commonly isolated pathogen
~80% of all UTI
Community-Acquired UTI
Uro-pathogens
? E.coli, Klebsiella spp.
-intrinsic gut organisms
-highly motile
-produce fimbriae (pili) >>attachment
? Proteus, Morganella, Providencia
-Urease producing organisms
-increases urinary pH - leads to crystal formation >>biofilms
>>colonization of catheter
>>protects bacteria from host defenses & antibiotics
Nosocomial UTI
catheter associated
Urinalysis
? usually have increased numbers of WBC
? leukocyte esterase test is often positive
? nitrate test is often positive
Urinalysis
? Urine culture: significant bacteriuria usually defined as
> 105 bacteria / ml. (108 / litre)
? lower numbers may be significant in children and in catheter collected specimens
Specimen collection
? Should all patients with a suspected UTI be cultured?
? Community acquired vs nosocomial?
? Should all isolates be identified?
Susceptibility testing?
Specimen collection
? Clean catch mid stream specimens
- most frequently used method
- urethra cleaned prior to collection
- first void urine allowed to pass to clear urethra
- mid-stream collected in sterile container
? Collection bags (children)
- used in young children lacking bladder control
- often contaminated
- most meaningful result is a negative culture
Specimen collection
? Suprapubic aspiration / straight catheters
- invasive
- specimen obtained directly from bladder
? Indwelling catheters
- urine obtained by inserting needle into catheter or through diaphram
- preferable to obtain specimen from new catheter, rather than old catheter
Specimen transport
? Sent to and processed by lab as quickly as possible
- Require:method of collection
time of collection
patient's antibiotics
? Specimens not received by lab in 1-2 hours MUST be refridgerated
? Urines not received within 24 hours or not refridgerated will be rejected by laboratory
Antimicrobial Therapy
? Empiric Therapy
- based on most probable pathogens
- local rates of resistance
- acute infection vs chronic
- reinfection or relapse
- indwelling catheter etc
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Impaired bladder emptying
? Dysfunction
? Neuropathy
? VUR
? BOO
? Diverticulum
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Obstruction
? Any level
- VUR
- Calculi
? very difficult to eradicate if UTI and stones
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Intrarenal
? Renal scars
? Interstitial nephritis
? Papillary necrosis......（后略) ......
Urinary Tract Infections
UTI
? UTI - common affliction for which patients seek medical attention
? UTI can occur from infancy through old age
? more common in females than males
~20% of all females will experience a UTI during
their lifetime
UTI
Definitions
The term "UTI" represents a wide range of clinical syndromes
Bacteriuria: the presence of bacteria in urine
- does not necessarily imply infection
? Asymptomatic bacteriuria: presence of bacteria in the urinary tract in the absence of symptoms
- clinical significance controversial outside certain patient populations
- pregnant women
- patients undergoing invasive procedures
of the urinary tract
UTI
Definitions
? Cystitis: UTI presumed to be confined to the bladder
- painful/burning urination
- urgency or frequency
- absence of symptoms or physical signs suggesting
inflammation at other sites within the urinary tract
? Note: clinical criteria are notoriously inaccurate in identifying the actual anatomic site of infection
UTI
Definitions
? Pyelonephritis: clinical diagnosis which implies a more invasive infection
- inflammation of the kidney and renal pelvis is assumed to be present when patients have pain or tenderness involving the flank, together with other clinical or laboratory evidence of UTI
-fever, nausea, chills, malaise, headache, etc
UTI
Definitions
? Prostatitis: inflammation / infection of the prostate gland
- may present as acute or chronic
? Intrarenal abscess / perinephric abscess: collection of pus in the kidney or in the soft tissue surrounding the kidney
UTI
Definitions
? Complicated infections
- underlying abnormality that predisposes patient to UTI
or makes UTI more difficult to treat effectively
? Recurrent Infections
Relapse - recurrence of infection by same organism after discontinuation of treatment
Reinfection - recurrence of infection by a different organism after discontinuation of treatment
UTI
Pathogenesis
? UTI usually due to patients own intestinal flora
- ascending route of infection
- organisms enter the urinary tract in a retrograde fashion via the urethra
? Complicating factors such as catheters, nephrostomy tubes, surgery, urinary stones, etc
- allow organisms to enter and persist in urinary tract
- alter the typical spectrum of organisms
- may have multiple etiologies
UTI
Pathogenesis
? Elderly patients
- incontinant
- functionally impaired
- postmenopausal changes
- neurological alterations
? Pregnant women
- altered anatomy
? Hematogenous route
- endocarditis, bacteremias, tuberculosis
- disseminated infections
UTI
Etiology
? Majority of UTI are due to a single pathogen
? The Enterobacteriaceae responsible for 90% of all UTI
- gram negative bacilli
- facultatively anaerobic
- common intestinal flora
? Escherichia coli most commonly isolated pathogen
~80% of all UTI
Community-Acquired UTI
Uro-pathogens
? E.coli, Klebsiella spp.
-intrinsic gut organisms
-highly motile
-produce fimbriae (pili) >>attachment
? Proteus, Morganella, Providencia
-Urease producing organisms
-increases urinary pH - leads to crystal formation >>biofilms
>>colonization of catheter
>>protects bacteria from host defenses & antibiotics
Nosocomial UTI
catheter associated
Urinalysis
? usually have increased numbers of WBC
? leukocyte esterase test is often positive
? nitrate test is often positive
Urinalysis
? Urine culture: significant bacteriuria usually defined as
> 105 bacteria / ml. (108 / litre)
? lower numbers may be significant in children and in catheter collected specimens
Specimen collection
? Should all patients with a suspected UTI be cultured?
? Community acquired vs nosocomial?
? Should all isolates be identified?
Susceptibility testing?
Specimen collection
? Clean catch mid stream specimens
- most frequently used method
- urethra cleaned prior to collection
- first void urine allowed to pass to clear urethra
- mid-stream collected in sterile container
? Collection bags (children)
- used in young children lacking bladder control
- often contaminated
- most meaningful result is a negative culture
Specimen collection
? Suprapubic aspiration / straight catheters
- invasive
- specimen obtained directly from bladder
? Indwelling catheters
- urine obtained by inserting needle into catheter or through diaphram
- preferable to obtain specimen from new catheter, rather than old catheter
Specimen transport
? Sent to and processed by lab as quickly as possible
- Require:method of collection
time of collection
patient's antibiotics
? Specimens not received by lab in 1-2 hours MUST be refridgerated
? Urines not received within 24 hours or not refridgerated will be rejected by laboratory
Antimicrobial Therapy
? Empiric Therapy
- based on most probable pathogens
- local rates of resistance
- acute infection vs chronic
- reinfection or relapse
- indwelling catheter etc
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Impaired bladder emptying
? Dysfunction
? Neuropathy
? VUR
? BOO
? Diverticulum
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Obstruction
? Any level
- VUR
- Calculi
? very difficult to eradicate if UTI and stones
Management of UTI
? Anatomical/Functional Predisposition to UTI
- Intrarenal
? Renal scars
? Interstitial nephritis
? Papillary necrosis......（后略) ......