UTI

Question 1

important history questions

Answer 1

• sexual contact? barrier contraception?
• frequency, urgency of urination, incontinence?
• cramping pain?

Question 2

describe cystitis and those at high risk

Answer 2

infection of bladder, common

high risk in females, increased post-menopause women due to less oestrogen supporting protective bacteria

Question 3

risk factors for cystitis

Answer 3

females = past UTI, sex, diaphragm use, pregnancy, diabetes

males = lack of circumcision, AIDS, MSM

important in older people = bladder function, neurological disease

Question 4

factors contributing to recurrent cystitis

Answer 4

• intercourse
• contraception (some barrier forms, latex-allergy)
• abnormal urinary tract

Question 5

diagnosis of cystitis

Answer 5

• symptoms = high frequency, urgency, cramp pain
• midstream urine dipstick
  - leucocyte esterase/WBC
  - microscopy, culture

Question 6

causative organisms

Answer 6

E. coli (>80%)

S. saprophyticus (common in young women)

Question 7

uropathogenic E coli infection

Answer 7

• fimbriae mediate urothelium attachment
• strains that sequester iron are more virulent
• polysaccharide capsule resists phagocytosis
• alpha-haemolysin damages urothelium and neutrophils
• damaged urothelium releases:
  - IL-8 = recruits neutrophils
  - IL-1, TNF-a, IL-6 = fever, malaise

Question 8

defence against uropathogens

Answer 8

• microbial flora
• urine is inhospitable (pH, Osmo)
• urination
• prostatic fluid inhibits bacterial growth
• innate and adaptive immunity
• tommy-horsfall protein = formed in LOH, binds to bacteria to pass by urination

Question 9

treatment of cystitis

Answer 9

most cases resolve, over many months

• only prescribe when symptoms are present
• broad-spectrum antibiotics
  = oral trimethoprim
  or nitrofurantoin
  (for serious infections = co-trimoxazole)

Question 10

trimethoprim

Answer 10

• inhibits folate synthesis (inhibits dihydrofolate snythetase enzyme)
• interferes with division
• avoid folate antagonists in pregnancy
• long periods can suppress bone marrow function
• allergies = rash

Question 11

describe pyelonephritis and its presentation

Answer 11

• infection of kidneys
• associated with bacteraemia
• sever flank pain radiating to groin
• dysuria, haematuria
• fever, nausea, tachycardia

Question 12

management of pyelonephritis

Answer 12

• many admitted and tx in hospital
• investigate with blood & urine culture
• blood test to determine organ impairment (renal)

Question 13

treatment of pyelonephritis

Answer 13

• initial IV antibiotics, then change to oral
• IV gentamicin
• augmentin useful alternative