UTI

Question 1

Where are the locations for upper UTIs and lower UTIs?

Answer 1

Upper - above vesico-ureteral sphincter (ureter, kidneys)

Lower - below sphincter (bladder, urethra)

Question 2

How common are UTIs?

Answer 2

Up to 1/3 of women aged 24 would have had _>1 episode of UTI

50% women treated for symptomatic UTI lifetime

Question 3

What are defences the urinary tract has against bacterial colonisation?

Answer 3

Emptying of bladder during micturition

Vesico-ureteral valves

Immunological factors

Mucosal barriers

Urine acidity

Question 4

What could ascending colonisation of bacteria from urethra cause?

Answer 4

Bladder -cystitis

Kidney - pyelonephritis

Question 5

What ages are UTIS most common and why?

Answer 5

Infancy and pre-school 0-10yrs poor hygiene

20yrs honeymoon cystitis (lots of sex)

23-27yrs pregnancy

Men low after 5yrs then increases after 60yrs prostatism

Question 6

What’s the most common cause of honeymoon cystitis? Why can’t it be picked up on a urine dipstick?

Answer 6

Staphylococcus saprophyticus

Does not reduce nitrate to nitrites like most gram positive uropathogens

Question 7

Risk factors for UTIs

Answer 7

Obstructive - stones/ BPH/ retroperitoneal fibrosis

Neurological conditions affecting bladder emptying - multiple sclerosis, stroke

Pregnancy - enlarged uterus, hormonal effects on relaxation of musculature

Abnormal renal tract - vesico-ureteric reflux in children, indwelling urinary catheter

Impaired host defence - diabetes mellitus, immunocompromised

Question 8

What are the majority of UTIs caused by?

Answer 8

Coliforms (gram negative) - most common: Escherichia Coli

Question 9

What virulence factors does E.coli have?

Answer 9

Flagella - movement

Pili - attachment

Capsular polysaccharide - colonisation

Haemolysin, toxins - damage host membranes and causes renal damage

Question 10

Clinical syndromes of UTIs

Answer 10

Cystitis - lower

Pyelonephritis - upper

Chronic pyelonephritis

Asymptomatic bacteriruia (pregnancy/ >65yrs)

Septicaemia (if not treated)

Question 11

Clinical presentation of cystitis

Answer 11

Dysuria 
Cloudy urine 
Nocturia or frequency urgency 
Suprapubic tenderness 
Haematuria 
Pyrexia (usually mild)

Question 12

Clinical presentation of pyelonephritis

Answer 12

High fever 
\+/- rigors
Loin pain/ tenderness
Nausea/ vomiting 
\+/- cystitis symptoms

Question 13

Differentials for dysuria

Answer 13

Cystitis 
Pyelonephritis 
STIs
Post sexual intercourse 
Contact irritants 
Menopause 
Strophic vaginitis
Vaginal atrophy

Question 14

What is an uncomplicated UTI?

Answer 14

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

Question 15

What is a complicated UtI?

Answer 15

_>1 factors that predispose to persistent infection, recurrent infection or treatment failure e.g.

Abnormal urinary tract

Virulent organism e.g staph aureus

Impaired host defence

Impaired renal function

Treat as complicated if pregnant, treatment failure, recurrent, suspected pyelonephritis, Male, children, complications

Question 16

Who can get uncomplicated UTIs?

Answer 16

Infections in children and men and cases of pyelonephritis may meet criteria of uncomplicated

BUT in practice most cases children/ men/ pregnant women are investigated and managed as complicated

Question 17

How do you investigate UTIs?

Answer 17

Mid stream urine sample -> urine dipstick: leukocyte esterase = WBCs, nitrites = bacteria, blood, Ph, protein

Clean catch children

Collection bag (20% false positives)

Catheter sample

Supra-pubic aspiration most accurate but painful

For complicated: culture urine within 4 hrs refrigerate or boric acid preservative - 37d for 18hrs

All children consider/ septic/ males/ vesico-ureteric reflux: Imagining of urinary tract

Question 18

When is urine dipstick not useful?

Answer 18

Patients >65 yrs - asymptomatic infection common up to half population

Catheterised patients always positive

All 3 or 2 symptoms (dysuria, nocturia, cloudy urine) - women <65 not necessary ✅antibiotics

Question 19

When would you get sterile Pyuria?

Answer 19

Raised WBCs but no growth

• prior antibiotics
• urethritis (chlamydia/ gonococci)
• vagina infection/ inflammation
• TB of renal tract (prolonged intubation)
• appendicitis
• fastidious organisms - slow growing v rare

Question 20

When is asymptomatic bacteriuria screened for and treated?

Answer 20

On in pregnancy (higher risk premature and pyelonephritis)

Question 21

Treatment UTIs

Answer 21

Increased fluids

Regular Malaysia

Address underlying disorders

3 day course antibiotics uncomplicated- nitrofurantoin/ trimethoprim (high resistance don’t give repeatedly)/ pivmecillinam/ fosfomycin

5-7 days complicated lower UTI nitrogurantoin/ trimethoprim/ pivmecillinam/ fosfomycin/ cefelexin - review susceptibility

Catheter sample urine only treat if systemically unwell

Pyelonephritis/ septicaemia 7-10 day course use systemic agent/ possibly IV: co-amoxiclav/ ciprofloxacin/ gentamicin IV nephrotoxic

Question 22

When would you give prophylaxis?

Answer 22

_>3 episodes one year

Despite education and changes

No treatable underlying condition

Susceptibility results