14. UTI

Question 1

What is a common source of gram negative septicaemia?

Answer 1

UTI.

Question 2

Name 3 factors which increase a patients risk of developing a UTI.

Answer 2

Shorter urethra (females).
Obstruction eg enlarged prostate, pregnancy, stones, tumours.
Neurological problems eg incomplete emptying, residual urine.
Ureteric reflux - valves not fully developed in children leading to backflow.

Question 3

Name 2 bacterial virulence factors that can help them infect a patient causing a UTI.

Answer 3

Fimbriae allow attachment to host epithelium.
K antigen permits production of polysaccharide capsule.
Haemolysins damage host membrane and cause renal damage.
Urease breaks down urea creating a favourable environment for bacterial growth.

Question 4

What is the most common microorganism causing UTI and what does it’s gram stain look like?

Answer 4

E. coli.

Gram negative bacilli.

Question 5

What are the 5 different clinical syndrome related to UTI?

Answer 5

Cystitis - lower UTI.
Acute pyelonephritis - upper UTI.
Chronic pyelonephritis - repeated UTI.
Asymptomatic bacteriuria - pregnancy.
Septicaemia with or without shock.

Question 6

Give 3 symptoms of cystitis.

Answer 6

Dysuria.
Frequency.
Urgency.
Sometimes low grade fever.

Question 7

Give 2 symptoms of pyelonephritis.

Answer 7

Fever.
Loin pain.
May have dysuria and frequency.

Question 8

What is the definition of an uncomplicated UTI?

Answer 8

Infection by a usual organism in a patient with a normal urinary tract and normal urinary function.

Question 9

What is the definition of a complicated UTI?

Answer 9

UTI when one or more factors are present that predispose the person to persistent infection, recurrent infection or treatment failure.

Question 10

Give 2 examples of complicated UTIs.

Answer 10

UTI with abnormal urinary tract eg indwelling catheter.
Virulent organism eg staph aureus.
Impaired host defences eg poorly controlled diabetes (optimises bacterial growth) or immunosuppression.
Impaired renal function.

Question 11

Cases in children, men and pregnant women are investigated and managed as what type of UTI?

Answer 11

Complicated.

Question 12

When would you do a urine culture if you suspected a UTI?

Answer 12

In complicated UTI.

Question 13

How is an MSU transported?

Answer 13

4 degrees celcius in boric acid.

Question 14

How would you visually inspect a urine sample for a UTI?

Answer 14

Look for turbidity.

Question 15

When is dipstick testing in a suspected UTI useful?

Answer 15

Useful to exclude UTI in:

children older than 3 years, men with mild/non-specific symptoms, elderly/institutionalised women.

Question 16

What would you see on a urine microscopy that would indicated that the urine is contaminated?

Answer 16

Squame epithelial cell.

Question 17

What is significant bacteriuria?

Answer 17

The amount to bacteriuria needed to distinguish between asymptomatic females (where the sample has become contaminated) and females with pyelonephritis. >10^5 cfu/ml distinguishes bacteriuria from contamination.

Question 18

In a symptomatic adult woman with a UTI, half will have significant bacteriuria. What will the other half have and what is it?

Answer 18

Urethral syndrome - low count bacteriuria, fastidious organisms, vaginal infection/inflammation, sexually transmitted pathogens causing urethritis, mechanical, physical, chemical causes.

Question 19

In what UTIs would you do imaging of the urinary tract?

Answer 19

All children.
Septic patients to identify renal involvement.
Posterior urethral valves in males.
Vesicles-ureteric reflux in females.

Question 20

Name 3 causes of sterile pyuria.

Answer 20

Antibiotics.
Urethritis (chlamydia/gonorrhoea).
Vaginal infection.
Chemical inflammation.
TB.
Appendicitis.
Fastidious organisms.

Question 21

What is asymptomatic bacteriuria?

Answer 21

Bacteriuria, usually in elderly females, with associated pyuria but no other symptoms. Only needs treating in pregnancy and urological surgery.

Question 22

How would you treat simple cystitis?

Answer 22

3 day course of trimethoprim.

Question 23

When would you only treat a patient with a UTI shown with CSU?

Answer 23

If systemically unwell.

Question 24

How would you treat a patient with complicated UTI?

Answer 24

5-7 day course of trimethoprim. Post treatment follow-up cultures in paediatric patients and pregnant women.

Question 25

How would you treat a patient with pyelonephritis/septicaemia?

Answer 25

14 day course of co-amoxiclav.

Question 26

When would you treat a patient with prophylaxis against UTIs? What would you use?

Answer 26

3 or more episodes in one year and no treatable underlying condition.
Trimethoprim single nightly dose.

Question 27

Name 2 structural abnormalities that can cause UTIs in children.

Answer 27

Posterior urethral valves in boys.
Vesicoureteric reflux, with or without renal hypoplasia.
Duplex ureters.

Question 28

What is vesicoureteric reflux?

Answer 28

Reflux of urine from the bladder to the kidneys via the ureters.