UTIs and their treatment

Question 1

what is urine

Answer 1

generally considered a sterile bodily fluid

- but low levels of bacteria can be found in urine of healthy adults

Question 2

define bacteriuria

Answer 2

presence of bacteria in urine

Question 3

what is asymptomatic bacteriuria

Answer 3

1. bacteriuria in apparently healthy people with no associated symptoms
   - bacteriuria alone doesn’t require treatment
   - common in >65years
   - common in people with urinary catheters

Question 4

give examples of risk factors for bacteriuria

Answer 4

• gender
• sexual activity
• age
• co morbidity
• nursing/care home residence
• urinary catheter
• pregnancy

Question 5

what are the 2 types of UTI

Answer 5

1. lower UTI- cystitis
2. upper UTI- pyelonephritis
   - UTIs can be classified as uncomplicated or complicated

Question 6

what is uncomplicated UTI

Answer 6

1. anatomy of UT normal
2. no underlying condition contributing to infection
3. unlikely to result in serious kidney damage
4. most LUTI are uncomplicated
   - usually women

Question 7

what is complicated UTI

Answer 7

1. anatomy of UT is not structurally normal or has a metabolic or functional problem
2. usually men- more likely due to the long urethra
3. if theres kidney stones present
4. key issue is the increased risk of treatment failure

Question 8

what are UTI pathogens

Answer 8

1. almost always bacterial
   - commonly commensal bacteria (normal flora) of GIT or genitalia
2. fungal UTI infections are possible in immunosuppressed patients

Question 9

what are the likely sources of UTI

Answer 9

1. gram negative most likely- eg. E coli, Klebsiella pneumonia, enterobacter
2. gram positive less likely- eg. enterococcus, staphylococcus

Question 10

what are the signs and symptoms of lower UTI

Answer 10

1. dysuria
2. frequency
3. urgency
4. polyuria
5. fever
6. haematuria
7. offensive smell
8. elderly- confusion, behavioural changes

Question 11

what are the signs and symptoms of upper UTI

Answer 11

same as LUTI but with:

• loin pain (very severe)
• abdominal tenderness
• often very unwell (hospital treatment)

Question 12

how is UTI diagnosed

Answer 12

1. urine dipstick- simple initial screen
2. mid stream urine (MSU)- increased likelihood of obtaining pure culture
3. signs and symptoms

Question 13

describe the process of using a urine dipstick

Answer 13

1. leukocytes, nitrates and blood all indicative of UTI
   - nitrates due to presence of gram negative bacteria
2. simple initial test, easy to do and non invasive
3. gives a crude indication
4. never use in isolation

Question 14

describe the process of using a clean catch MSU

Answer 14

1. let urine flow at first then hold for a second and resume stream into cup or sample bottle
2. clean catch avoids Sample contamination from normal flora around the genitals
   - genital area must be cleaned extensively with a wipe immediately before urinating
3. obtains a more pure culture

Question 15

what are the general principles of UTI treatment

Answer 15

1. only treat if symptomatic
   - especially if catheterised or >65years
2. use narrowest spectrum possible
   - switch from broad spectrum when sensitivities known
3. lower UTIs treatment duration
   - men 7 days
   - women 3 days

Question 16

what are the steps to treating infections

Answer 16

1. look at local empiric guidelines- consider what likely source is
2. look at first line recommended treatment- consider patient/clinical/drug related factors
3. select the best drug, dose, route and duration
4. monitor

Question 17

what drugs are used for the treatment of UTI

Answer 17

1. nitrofurantoin- LUTI choice
2. trimethoprim- LUTI choice
3. gentamicin
4. co amoxiclav
5. quinolone

Question 18

describe how nitrofurantoin is used as first line treatment of UTI

Answer 18

1. broad spectrum, bactericidal
2. interferes with bacterial RNA/DNA synthesis
3. active against E coli and many other likely gram negative organisms
4. not effective against pseudomonas
5. absorbed from GIT, bioavailability not great but the drug concentrates very well in the urine
   - 40% excreted unchanged in urine
6. used for LUTI only
7. can’t be used in renal impairment

Question 19

describe the characteristics of trimethoprim

Answer 19

1. broad spectrum, bacteriostatic
2. interferes with bacterial folic acid synthesis
   - inhibits dihydrofolate reductase enzyme, blocking the reduction of dihydrofolic acid to tetrahydrofolic acid
3. not affective against pseudomonas
4. increasing resistance is now significantly limiting use
   - no longer recommended in some areas
   - in renal impairment, reduce dose or avoid

Question 20

what other drugs can be used for treatment of UTIs

Answer 20

1. pivmecillinam- penicillin type, gram - narrow spectrum, for LUTI
2. Fosfomycin- broad spectrum, for LUTI
3. methenamine- long term prophylaxis therapy for recurrent UTIs
   - these can be used in allergies, or where other treatments failed, or there is known resistance

Question 21

describe the treatment of UTI in pregnancy

Answer 21

1. classed as complicated infection
2. all women should have urine cultures taken at first antenatal appointment
3. treat asymptomatic bacteriuria in pregnant women
4. duration of Ax is always 7 days in pregnant women
5. high risk of developing into pyelonephritis, eradication of bacteriuria significantly reduces rsik

Question 22

what should be done in catheterised patients

Answer 22

1. do not treat if positive dipstick and/or MSU
2. must have symptoms
3. all catheterised patients will have bacteriuria
4. if they do need to be treated (symptomatic):
   - first line Abx according to guidance
   - remove the in dwelling Catheter