MI: Urinary Tract Infection Pt.1 Flashcards
In which situation is asymptomatic bacteriuria clinically significant?
Pregnancy - associated with increased risk of complications
What is the difference between uncomplicated and complicated UTI?
- Uncomplicated - infection in a structurally and neurologically normal urinary tract
- Complicated - infection in a urinary tract with functional or structural abnormalities (includes indwelling catheters and calculi)
In which groups of patients are UTIs considered ‘complicated’?
- Men
- Pregnant women
- Children (may have structural abnormality)
- Hospitalised patients
Which organism most commonly causes UTI?
E. coli
List some other organisms that cause UTI.
- Staphylococcus saprophyticus - UTI young healthy women - probably 2nd after E. coli
- Staphylococcus epidermidis - can cause infection in the presence of prosthesis (e.g. procedures, indwelling catheters)
- Proteus mirabilis - struvite kidney stones
- Klebsiella aerogenes
- Enterococcus faecalis
Which virulence factor allows E. coli to stick to the urinary tract epithelium?
P fimbriae
List some antibacterial host defences in the urinary tract.
- Urine (osmolality, pH, organic acids)
- Urine flow and micturition
- Urinary tract mucosa (bactericidal activity, cytokines)
What is an ascending UTI?
Infection of the lower urinary tract may pass up the ureters into the renal pelvis and parenchyma
List some causes of urinary tract obstruction.
Extra-renal
- Valves, stenosis or bands
- Calculi
- BPH
- External ureter compression (gravid uterus, tumour)
Intra-renal
- Nephrocalcinosis
- Nephropathy (uric acid, analgesic, hypokalaemic)
- Polycystic kidney disease
Neurogenic malfunction
- Poliomyelitis
- Tabes dorsalis (demyelinating condition caused by advanced syphilis)
- Diabetic neuropathy
- Spinal cord injuries
What is vesicoureteric reflux?
- A condition in which urine can reflux into the ureters
- It results in a residual pool of infected urine in the bladder after voiding
- It can result in scarring of the kidneys
Describe how UTI can become established via the haematogenous route.
The kidney is a frequent site for abscesses in patients with S. aureus bacteraemia or endocarditis (not really a UTI)
NOTE: Gram negative bacilli like E. coli rarely spreads via the haematogenous route
Outline the symptoms of UTI in:
- Neonates and children < 2 years
- Children > 2 years
Neonates and children < 2 years: (non-specific)
- Failure to thrive
- Vomiting
- Fever
Children > 2 years: (more localised)
- Frequency
- Dysuria
- Abdominal or flank pain
List some symptoms of lower UTI
- Bladder and urethral mucosal irriation - frequent and painful urination
- Suprapubic pain
- Haematuria
- Absence of fever (most of the time)
List some symptoms of upper UTI.
- Fever (and rigors)
- Flank pain
- Lower urinary tract symptoms (frequency, urgency, dysuria)
- At times LUTS preceed the onset of fever and upper tract symptoms
Describe the symptoms of UTI in older patients.
- Mostly asymptomatic
- Atypical symptoms (e.g. confusion, abdominal pain)
NOTE: classic symptoms such as frequency and dysuria are common in older people and does not necessarily suggest that there is an infection
