UTIs Flashcards
What is asymptomatic bacteriuria?
Presence of bacteria in the urine with no symptoms
In preg its associated with pre-term labour
High prevalence in older people especially females
What host factors enable UTIs?
Shorter urethra = more infect in females
Obstruction = enlarged prostate, preg, stones, tumours
Neurological probs = incomplete emptying, residual urine
Ureteric reflex = ascending infec from bladder
Outline the possible sites and causes of urinary tract infection
PUJ = calculi
Ureter = calculi, Ca, retroperitoneal fibrosis
Bladder = neuropathic bladder
VUJ = calculi
Bladder neck = hypertrophy
Prostate = BPH, Ca
Urethra = stricture
What bacterial factors enable UTI?
Fimbriae = attachment to ep
Haemolysins = damage host mem, renal damage
K Ag = prod of polysaccharide capsule
Urease = breaks down urea creating environment favourable for bacterial growth
What is cystitis?
Lower UTI
What is pyelonephritis?
Upper UTI
Describe the signs/symptoms of lower UTIs
Dysuria
Frequency
Urgency
Sometimes low grade fever
Describe the signs/symptoms of an upper UTIs
Fever
Loin pain
May have dysuria, frequency
Define an uncomplicated UTI
Infection by a usual organism in a pt with a normal urinary tract and normal urinary function
Define a complicated UTI
When one or more factors are present that predispose the person to persistent infect, recurrent infect, or treatment failure
Abnormal urinary tract
Virulent organism
Impaired host defences
Impaired renal function
How can we collect a urine sample?
MSU = first part may be contaminated
Clean catch in children
Collection bag
Catheter sample (never collect from bag, it will always be infected, always use ports)
Supra-pubic aspiration
Transport = 4 degrees, with boric acid (helps stem overgrowth)
Outline near pt testing
Turbidity = clear then non infect
Dipstick = leucocyte esterase, nitrite, haematuria, proteinuria
What factors are important on a urine dipstick regarding a UTI?
Leucocyte esterase = presence of WBCs
Nitrite = bacteria produce urease which breaks down to nitrites
Haematuria = inflam, cancer, infection
Proteinuria = DM, hypertension
What is always seen on a urine dip in catheterised pts?
WBCs
Bacteria
What is a significant bacterial count in urine analysis?
10^5 cfu/ml
What is the role of culture in a urine infection?
Identifying the causative organism
E.coli = pink
Klebsiella = creamy/white
Sensitivity testing
Why do we image the urinary tract?
Considered in all children with UTI
Valuable in septic pts to identify renal involvement
What is sterile pyuria and its causes?
Presence of elevated WBCs in urine which appears sterile using standard culture techniques
UTI with fastidious organism
Renal TB
Vaginal infection/inflam
Outline the treatment for UTI
Increase fluid intake
Uncomplicated = 3 day course Abx – trimethoprim
Complicated lower = 5-7 day course Abx – trimethoprim, nitrofurantoin, cephalexin
Describe the treatment of pyelonephritis/septicaemia
14 day course
IV initially
Co-amoxiclav, ciprofloxacin, gentamicin
When is prophylaxis for UTIs given?
Particularly useful for children with repeated episodes
3 or more episodes in 1 year
When no treatable underlying condition
Trimethoprim/nitrofurantoin
