Urinary Tract Infection Flashcards
What does the upper urinary tract comprise of
o Kidney
o Renal pelvis
o Ureter
What does the lower urinary tract comprise of
o Bladder
o Urethra
What does the urothelium lining consist of
o Transitional epithelium in the upper tract and bladder
o Pseudostratified columnar in membranous and spongy urethra
What is urinary tract infection
o Inflammatory response of urothelium to bacterial invasion
o Inflammatory response causes symptoms
How do urinary tracts become infected
o Ascending: retrograde ascent of bacteria up urethra
- Bacteria from large bowel colonise perineum and ascend to bladder
- May ascend from bladder to kidney via ureter = Increased risk: vesicoureteric reflux/impaired ureteric peristalsis e.g. in
patients with renal stones
Haematogenous
Lymphatics
- inflammatory bowel disease
- retroperitoneal abscess
What are the risk factors of urinary tract infections
Previous UTI
Female gender
Congenital abnormality / reflux nephropathy
Renal calculi
Bladder catheterisation / Intermittent self catheterisation for neurogenic bladder
Diabetes
Drugs – Sodium Glucose Transporter-2 antagonists (Gliflozins) used in diabetes
Bladder Cancer
What is the history of urinary tract infections
Previous UTIs
Sexual history
Renal tract problems – eg stones, congenital abnormalities
Any symptoms of bladder cancer
What are the investigations of urinary tract infections
Urine dipstick – leucocytes, nitrites, protein. May be false positive in elderly o Nitrite in urine – 90% sensitive, but 35-85% specific for UTI
Mid stream urine (MSU) for MC&S – common bacteria are gram –ve such as E.Coli, Pseudomonas, Klebsiella, Proteus. Gram +ve such as strep faecalis or staph aureus are less common
Recurrent UTI – USS renal tract or CT KUB (kidney, ureter, bladder)
How do you manage pyelonephritis
May require intravenous therapy with co-amoxiclav
If patient stable, out-patient antibiotic therapy (OPAT) is a possibility
How do you manage recurrent UTI
Consideration given to rotating antibiotics, post coital antibiotics
how do UITs come from the ascending route
- bacterial from large bowel colonise the perineum and ascend to the bladder
- may ascend from bladder to kidney via the ureter
what are the risk factors for a UTI coming from the bladder to the kidney
- veiscouretic reflux
- impaired ureteric peristalsis
- stones
What is bacteriuria
= presence of bacteria in urine
What is pyuria
= presence of white blood cells in the urine
if you have bacteriuria but no pyuria what does this suggest
- suggest that you have colonisation of bacteria rather than active infection
What does pyuria imply
- implies an inflammatory response of urothelium in response to bacterial infection
If you have pyuria but not bacteruria what does this suggest
- carcinoma in situ
- TB infection
- bladder stone
what is an uncomplicated UTI
- uncomplicated - normal urinary tract structure and function
describe how you treat an uncomplicated UTI
- mainly women
- respond quickly to a short course of antibiotics
what organisms cause a UTI
E.coli = 85% community acquired cases, 50% hospital acquired cases
- Others = staphylococcus saprophytic, streptococcus faecalis, proteus, klebsiella
What is an complicated UTI
- underlying anatomical/functional abnormality
describe a complicated UTI
- take longer to respond to antibiotics and often reoccur
- E.coli: 50% of cases
- Others - streptococcus faecalis, staphylococcus aureus, Staphylococcus epidermis, Pseudomonas
Name 3 categories of UTI
- isolated
- recurrent
- unresolved
What is an isolated UTI
- at least 6 months between infections
