UTIs Flashcards
Define a UTI
An infection in any part of the urinary system - kidneys, ureters, bladder, urethra
Most involve lower urinary tract (bladder and urethra), some involve upper UT (above bladder)
Mostly caused by bacteria present in bowel flora (some fungal)
What are the symptoms of a UTI?
- Change in urination frequency
- Dysuria (pain)
- Passing only small amount of urine
- Haematuria
- Pyuria (foul smelling and/or cloudy)
- urgency
- Urinary incontinence
More severely
- rigors - fevery shake
- pyrexia
- N+V
- acute confusional state (particularly elderly people)
Significant vs asymptomatic bacteruria
Significant = number of bacteria in voided urine that exceed the number usually due to contomaniation from the anterior urethra (.10^5 bacteria/ml)
Asymptomatic = significant bacteruria but without symptoms
what are the three main sites of UTI?
Lower UTI - urethritis and cystitis
Upper UTI - pyelonephritis (kidney infection)
What main symptoms would you get with each of the three main UTI sites?
Pyelo = upper back and flank pain, fever, shaking, n + V
Cystitis = pelvic pressure, urge incontinence, frequent and painful urination, blood in urine
Urethritis = burning
Describe the different presentation of UTI in different patient groups
- Common in women - shorter urethra, and a higher risk of contamination from faecal material - can occur when there is no underlying problem
- Uncommon in men and kids - suspicion that there is an underlying abnormality of the urinary tract
- Increases in both sexes with age
- prostatism in men from growing prostate increases the risk massively
What are the risk factors of UTIs?
- female gender, increasing age, recent antibiotic use, recent sexual activity, new sexual partner, use of spermicide, diabetes, presence of catheter, institutionalisation, pregnancy
What are the different types of UTI?
Complicated UTI
- infections in a urinary tract with abnormalities:
- diabetes, kidney stones, blockages, developmental abnormalities
Uncomplicated UTI
- infection in a normal urinary tract
- persistent infection unlikely to cause kidney damage
What process do bacteria have to take to cause a UTI?
- get into the urinary tract
- adhere to the epithelium
- multiply and cause inflammation
What are the two possible routes of infection?
- ascending route - enter through urethra (much more common in females)
- Haematogenous route - blood-borne bacteria get into kidney
What is the main cause of infection by haematogenous route?
S.aureus - Gram + cocci
What is a CAUTI?
Catheter-associated UTI
- most common healthcare-associated infection in acute care hospital setting
- bladder doesnt fully drain, bacteria can grow in this and cause infection.
- there is also a space between the catheter and the epithelial layer of the urinary tract, which allows space for organisms to grow
- they can also grow on the inside of the catheter
What is vesicoureteric reflex?
When urine pools in the ureter and up to the kidney
How are UTI diagnosed?
- Dipstick analysis
- Urine microscopy - leukocytes indicate infection
- Urine culture
- should always culture in men with a history suggestive of a UTI, regardless of results of dipstick
- Ultrasound evaluation of upper UT
What is the empirical treatment of UTIs?
Lower UTI
- trimethoprin - usually the first line antibiotic, inhibits folic acid synthesis (generally avoided during pregnancy)
- Nitrofurantoin - damages bacteria so they cannot divide and replicate
Upper UTI
- cephalosporin (3rd generation beta-lactam) or quinolone (eg ciprofloxacin) for up to 14 days
