UTI
Fact Sheet
Incidence
Lifetime incidence in adult women is 50-60%
10% of postmenopausal women have had a UTI in the past year
Frequency in young sexually active women are 0.5 episodes per year
Peak incidence between ages of 18 and 39
After the first episode of a UTI
27% of women have a recurrence within 6 months
3% have a second recurrence
Reference
https://www.uptodate.com/contents/acute-simple-cystitis-in-women
Microbiology
E. coli = 75%
Klebsiella = 6%
Staph saprohyticus = 6%
Enterococcus = 5%
Group B strep = 3%
Rest = 5%
Urinalysis
Dipsticks have a 75% sensitivity and 82% specificity for UTI when leukocyte esterase is present suggesting pyuria
The absence of pyuria should make you consider alternative diagnoses
Differential Diagnosis
Vaginitis - If vaginal discharge, odor, pruritis, dyspareunia, and absence of urinary frequency or urgency. Causes include fungal infection, bacterial vaginosis and trichomoniasis.
Urethritis - In sexually active women, particularly if pyuria on urinalysis but no bacteriuria. Causes include chlamydia, gonorrhoea, trichomoniasis, candida, HSV, and noninfectious irritants.
Painful Bladder Syndrome - Diagnosis of exclusion in women with ongoing discomfort with no evidence of infection or other identifiable cause.
Pelvic Inflammatory Disease - Lower abdominal pain and fever, occasionally dysuria.
Risk Factors
Certain factors can potentially increase your risk of developing a UTI. These include:
Recent sexual intercourse.
Recent history of UTI.
More common in women than men due to a shorter urethra.
Use of spermicide and contraceptive diaphragms.
Diabetes and Immunosuppression.
Urinary tract abnormalities such as scarring, reflux, stones, catheters, or prolapse.
Recent antibiotic use.
Recurrent UTIs are more likely if the first infection is < 15 years old.
Symptoms
Pain or a burning feeling when you urinate.
The need to urinate often.
The need to urinate suddenly or in a hurry.
Blood in the urine.
Lower abdominal pain.
Older people may only have incontinence, urinating at night, or a lack of well-being.
Fevers, chills and back pain suggest that you might be heading towards a kidney infection.
Management
First-line antibiotics work about 90% of the time. Second-line antibiotics are based on urine culture.
Trimethoprim - 300mg, 1 tablet taken daily in the evening for 3 days OR
Cephalexin - 500mg, 1 tablet taken twice daily for 5 days.
Nitrofurantoin
If there is stinging when you urinate, you can try urine alkalinising agents such as Ural sachets that reduce the acidity of the urine. These help with pain but do not treat or prevent UTIs.
Staying hydrated is important and may help by flushing the bacteria out of your urine.
Consider seeking help if worsening or ongoing symptoms despite 48 hours to 72 hours of antibiotic treatment as this may suggest the possibility of:
Antibiotic resistance which might require a change of antibiotics.
Progression to kidney infection, particularly if back pain, fever and feeling unwell.
Other diagnoses such as vaginitis, urethritis, or painful bladder syndrome.
Recurrent UTIs
Recurrent UTIs are common. After the first episode of UTI, 27% of women have a recurrence within 6 months, and 3% have a second recurrence.
Some options to prevent recurrent UTIs include:
Urinating after sex can be tried in women who note intercourse is a possible trigger.
Avoid spermicide use.
Topical vaginal oestrogen can help in post-menopausal women.
There is no strong evidence that increasing fluid intake, taking cranberry juice or tablets, or probiotics help to prevent infections.
If sexual intercourse is a trigger then you can try post-coital treatment with a single dose of antibiotic. First-line options are Trimethoprim 150mg or Cephalexin 250mg taken once after sex.
Another option is self-start treatment. This involves self-initiating a full course of 3 to 5 days of antibiotics when you have classical symptoms of a UTI including pain, frequency and urgency.
Some people prefer continuous low-dose treatment. This involves taking a single daily low dose of either Trimethoprim 150mg at night or Cephalexin 250mg daily for 3 to 6 months.
The final option is a weaker type of antibiotic called Methenamine hippurate (commonly called Hipprex). Hipprex only becomes active once you get a UTI and the urine becomes acidic. The recommended dose of Hipprex is 1g tablet taken twice daily.