URINARY TRACT INFECTIONS

Question 1

What would you expect white blood cell count to be in somebody with cystitis (lower urinary tract infection)?

Answer 1

Normal: would not expect any systemic symptoms either

Question 2

In someone with urgency, dysuria, polyurea as well as fever, flank pain, haematuria and costovertebral angle tenderness what is your top differential diagnosis? What would you expect to see in urine analysis?

Answer 2

Pyelonephritis, would expect to see blood and WBC casts in urine

Question 3

What are the 3 most likely bacteria to cause ascending pyelonephritis? What is the most likely bacteria to cause descending pyelonephritis?

Answer 3

• Ascending: E. coli, Proteus, Enterobacter
• Descending: Haematogenous (septicaemia, endocarditis)

Question 4

In someone with symptoms of cystitis and nitrates and leucocyte esterase in urine dip, which infection is most likely to be causing symptoms? Explain why

Answer 4

Most likely E. coli

Leukocyte esterase is produced by WBCs in urine

90% of UTI bacteria convert nitrates to nitrites, most common of which is E. coli. Some do not do this conversion e.g. enterococcus, staphylococcus saprophyticus

Question 5

What condition should you consider in a man with a urinary tract infection?

Answer 5

Diabetes

Question 6

Why does poor urinary flow increase risk of infection? Give examples of conditions in infants and adults that cause poor urinary flow

Answer 6

Allows bacteria to climb up urethra more easily

• infants: vesicoureteral reflux (caused by abnormal insertion of ureters into bladder), anatomical abnormalities (pictured)
• adults: urinary obstruction e.g. bladder tumours, enlarged prostate

Question 7

In someone with lower urinary tract infection symptoms with pyuria (WBC in urine) but no bacterial growth, what should you consider?

Answer 7

Chlamydia or gonorrhoea: asymptomatic in majority of women and can cause pyuria on urinanlysis without bacterial growth

Question 8

Corticomedullary scarring, blunted calyces, thyroidisation of the kidney, are all indications of which condition?

Answer 8

Chronic pyelonephritis, seen in vesicoureteral reflux in children

Question 9

A lack of improvement with antibiotic treatment of pyelonephritis is typical of which condition?

Answer 9

Renal abscess