Urinary tract infections

Question 1

What marks the boundary between the upper and lower urinary tracts?

Answer 1

Above the bladder = upper

Question 2

What areas of urinary tract are considered sterile?

Answer 2

Kidney/ureters

Bladder (not might not be the case!)

Question 3

What type of flora lines the urethra?

Answer 3

Perineal flora (skin/lower GI flora)

Question 4

What constitutes the perineal bacterial flora?

Answer 4

Skin - staph

GI
- anaerobic

• gram negative, aerobic enterobacteriaceae
• Gram positive - E.coccus spp

Question 5

What is the definition and clinical characteristics of cystitis?

Answer 5

Lower UTI

• Dysuria, polyuria, nocturia, haemturia
• freq/urgency
• supra-pubic pain

Question 6

What is the definition and clinical characteristics of pyelonephritis?

Answer 6

Upper UTI (kidney and/or renal pelvis)

• same symptoms as lower UTI (i.e. - ‘urias’/ab pain/freq/urgency) BUT with LOIN PAIN

Also systemic infection features - fever, rigour, nausea, D&V, elevated CRP and WBC

Question 7

What is the definition of urethral syndrome?

Answer 7

Symptoms of lower urinary tract infection but without evidence of infection

Question 8

What is meant by CFU?

Answer 8

Colony forming units (used as a means to identify bacteriuria)

Question 9

According to the Kass criteria, what is considered a significant bacteriuria in cfu/mL

Answer 9

10^5 cfg/mL

10^4-10^5 = probable

Question 10

What is the definition of asymptomatic bacteriuria?

Answer 10

Significant bacteriuria (i.e 10^5 cfg/mL) but WITHOUT symptoms of UTI

Question 11

What is the definition of pyuria? What are the potential causes for this?

Answer 11

Pus in urine but without organisms

Differential diagnosis - inflammation of urinary tract - trauma, kidney stones, polycystic kidney disease etc

Question 12

What are the predisposing factors for a UTI infection?

Answer 12

• Female
• Stasis e.g. pregnancy, stones, prostatic hypertrophy, neoplasm, strictures
• Instrumentation e.g. catheter, cystoscopy
• fistulae
• congenital conditions e.g. vesico-ureteric reflux
• sex

Question 13

What are the sources of UTI infection?

Answer 13

Perineum (movement of bacteria along lumen)

Fistulae

Haematogenous - seeding (rare)

Question 14

What are the 3 main causative organisms for UTI?

Answer 14

• E coli**
• Staph saprophyticus
• Proteus mirabilis

Question 15

What are the causes of sterile pyuria?

Answer 15

• inhibition of bacterial growth e.g. unprescribed antibiotics/antiseptic
• Fastidious organisms - hard to grow in culture e.g. gonorrhoea
• Urinary tract inflammation - renal/bladder stones, other renal disease

Question 16

What investigations should be carried out for a UTI?

Answer 16

• Dipstick testing (urinalysis)
• Blood test
• Microbiological
• Imaging

Question 17

What are the 4 ways by which urine is investigated?

Answer 17

• Mid stream urine
• Clean catch urine
• Cateter urine
• Supra pubic aspirate (directly from bladder)

Question 18

What condition is an early morning urine test used for?

Answer 18

Renal TB

Question 19

What further investigations should be performed followingurine test?

Answer 19

Ultrasound

Question 20

What antibiotic should be used for UTI?

Answer 20

Trimethoprim

Question 21

What are the requirements for antibiotics in the treatment of a UTI?

Answer 21

Cheap
Oral form
Present in urine
Effective against UTI bacteria 
Minimally toxic

Question 22

Who long should antibiotics should be administered for in a) males and b) females with CYSTITIS?

Answer 22

a) 7 days (longer course)

b) 3 days (shorter course)

Question 23

What antibiotics should you use for a pyelonephritis?

Answer 23

Empiric therapy e.g. ciprofloxacin, cefuroxime