Types of UTI
• ‘Simple’ or ‘uncomplicated’
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Female
First presentation
No signs of pyelonephritis
Not pregnant
• ‘Complicated’
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1
Pregnant
Male
Children
Recurrent
Pyelonephritis
Elderly
So what could it be?
Prodigy
Urinary Tract Infection (cystitis)
•
Typical features include:
– Dysuria, frequency, urgency, nocturia, haematuria, suprapubic pain, cloudy or
smelly urine
– Caused by bacteriuria, defined as >105 organisms/ml (102-104 if under sterile
conditions)
– ‘Simple’ UTIs are rarely associated with renal failure or sepsis (Hummers-Pradier.
Br J Gen Pract 2002; 52: 752-761)
Acute pyelonephritis
•
As above plus:
– fever (>38.5oC), loin/flank pain/tenderness, rigors, nausea, vomiting and malaise
– Can be life-threatening so requires urgent treatment
‘Urethral syndrome’
•
As cystitis but no bacteriuria
Sexually transmitted disease
e.g. chlamydia, gonorrhoea, herpes simplex, Candida
Other causes can include drugs (e.g. cyclophosphamide, NSAIDs), parasitic infection,
female menopause
2
So what are the management options here?
A 25 year old lady presents with a 48 hour history of needing to “go
the toilet a lot to pee” and it hurts when she does. She also thinks
she may have seen blood in her urine.
If we diagnose a ‘simple’ UTI (assuming she is not pregnant and
she has no history of UTI):
• Prognosis is good:
– Unlikely to cause serious complications
– But symptoms are unpleasant (to say the least)
• Up to 50% have no significant bacteriuria.
• Up to 50% will self-resolve in a few days, even without treatment.
– Giving antibiotics may cause more harm than good
– May disturb natural gut/vaginal flora and encourage Candida
growth.
• Can we predict who is more likely to have a bacterial cause for
their UTI?
3
Signs and symptoms to help predict a
bacteriuria
Bent S, et al. JAMA 2002; 287: 2701-2710
• The prevalence of a bacterial UTI in a young woman is
around 12%
• If she has certain signs and symptoms, this likelihood
increases:
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Dysuria (by about 1-2 times)
Frequency (by about 1-2 times)
Blood in urine (by about 2 times)
No vaginal discharge (by about 3 times)
No vaginal irritation (by about 3 times)
• So if more than 3 of these are present, it is reasonable
to assume a bacterial cause for the symptoms
– >70 out of 100 women will have a bacterial cause
4
What do the guidelines recommend
wrt dipstick testing?
Prodigy
•
If the woman has several clinical features typical of lower UTI
– Treat empirically without testing as urine dipstick test not helpful
•
If the woman has few clinical features typical of lower UTI
– Dipstick test the urine:
• Dipstick test positive (nitrite and LE both positive), diagnose UTI
• Dipstick test equivocal or negative (either or both negative), consider other
causes
Our thinking:
• If ‘barndoor’ symptoms (>3), don’t bother with the dipsticks – a
negative test may mislead you
• If diagnosis is unsure (1-2 symptoms) use them
• But don’t expect them to tell you the ‘right’ answer each time
5
Dip-sticking
• Urine dipsticks can be used when an uncomplicated UTI is suspected, but
cannot be relied upon to definitely exclude or confirm a diagnosis. A
positive nitrite test indicates bacteria in the urine (which have reduced
nitrate to nitrite) and therefore suggests UTI. However, a negative test
does not rule out UTI because some pathogens do not produce the
enzyme needed for the reduction, and frequent urination reduces the
time for the enzyme to act (morning specimens are most reliable [HPA]).
• A leucocyte esterase (LE) test indicates white blood cells in the urine and
also suggests that a UTI may be present, although contamination of the
specimen can give a false-positive result. A negative test, does not rule out
UTI since the test is insensitive and pyuria is not always present in UTI.
6
What does the PGD say?
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Three or more of the following symptoms:Dysuria
Frequency
Blood in urine
Absence of vaginal discharge
And no exclusions consider treatment.
Or one or two symptoms and a strong possibility of a UTI test with a
dipstick- A nitrite and/or leucocyte dipstick must be positive
• Patients may also have suprapubic pain, cloudy or foul smelling urine
• Vaginal discharge reduces the likelihood of the woman having a bacteria
urinary tract infection
7
What agent and for how long?
Prodigy, SIGN:
• A 3 day course of trimethoprim is effective for ‘simple’ UTI
• Nitrofurantoin is an option, but may be less convenient for patients
Cochrane Review – Milo G, et al. Date of last amendment 22 Feb 2005
• Compared the success of 3 day regimens with 5 days or more
• For symptomatic failure rates, no differences were seen
• For bacteriological failure rates, 3 days was slightly less effective
• Adverse effects were more common with longer courses
• Bottom line:- 3 days is fine for simple UTI, but not for those in whom
bacteriological cure is important, such as pregnancy
8
Simple UTIs - conclusion
• Look for ALARMS (temp>38.5oC, rigors, vomiting etc)
• Simple UTIs are generally self-limiting, non-serious infections but
can be very unpleasant
• Use decision rules to help with diagnosis:
– >3 symptoms (and self-reported) very likely to be bacterial cause
– 1-2 symptoms only - test with dipsticks (but they can mislead)
• Management options:
– Empirical antibiotics
• 3 days trimethoprim or nitrofurantoin
– Delayed prescription
– Symptomatic treatment ± delayed prescription
9
Case Study (npci.nhs.uk)
Beccie is a 25 year old woman who presents with
a 48 hour history of needing to urinate
frequently, and it hurts when she does. She also
thinks she may have seen blood in her urine but
wasn't sure.
What other information about her clinical
history would you like to know?
List all of the relevant pieces of information that
would be useful in diagnosing a simple UTI.
10
Model answer
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11
What other information about her clinical history would you like to know?
List all of the relevant pieces of information that would be useful in diagnosing a
simple UTI.
Sexual history
Had a UTI before?
Childhood history of bladder or kidney problems
Likely risk of pregnancy
Medication history (cyclophosphamide or NSAIDs can cause bladder irritation)
Foreign travel (parasitic infection)
Simple UTI is the diagnosis in young, sexually active, non-pregnant women where
it is not recurrent. UTIs in pregnant women, in older women that are recurrent or
in men, are not simple UTIs and need a different management approach. CKS
guidance is very useful for these patients.
• What other symptoms and signs would be
useful? List all of the signs and symptoms you
would need to ask the patient about to be
able to diagnose a simple UTI.
12
Model Answer
• Dysuria
• Frequency
• Vaginal discharge
• Vaginal irritation
• Loin or flank pain
• Temperature
• Rigours
• Nausea and vomiting
• General malaise
If systemic symptoms such as loin/flank pain or rigours are present, a upper
UTI or pyelonephritis should be considered. Again the management of this
condition is very different to that of a simple UTI.
13
• Beccie reveals the following information:
• She has never had a UTI before either as an adult
or a child.
• She has no back or loin pain as well as no vaginal
irritation or discharge.
• She takes the oral contraceptive pill and tells you
it is extremely unlikely she is pregnant as she had
her period last week.
• She takes no other medication at all.
• Her temperature is normal
14
• Which of the following tests, signs or symptoms are most
strongly correlated to the presence of a bacterial UTI? Rank
each item on your list with 10 meaning the diagnosis is very
likely and 0.1 being extremely unlikely:
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15
0.1, 0.5, 1, 2, 5, 10.
Dysuria
Frequency
Vaginal discharge
Vaginal irritation
Positive nitrite test
Positive leucocyte esterase test
No raised temperature
Blood in urine
Model answer
Likelihood ratios for these signs and symptoms (number of times
more likely they are to have a bacterial cause for UTI symptoms if
they have this sign/symptom compared with those who do not
have a bacterial cause) are:
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16
Dysuria 1.5
Frequency 1.8
Vaginal discharge 0.3
Vaginal irritation 0.2
Positive nitrite test* 6
Positive leucocyte esterase test* 1.5
Blood in urine 2.0