Lower urinary tract infections

Last updated: Tuesday, June 20, 2017

Case definition 
UTI is the second most common indication for empirical antimicrobial treatment in primary and secondary care but criteria for diagnosis vary widely. Click here to read the guidance issued by Public Health England.
• Women with severe or ≥ 3 symptoms of UTI including dysuria, frequency, suprapubic tenderness, urgency, polyuria, haematuria.
• Women with mild or ≤ 2 of the above symptoms and urine dipstick indicates infection.
• Men with dysuria, frequency, urgency, nocturia, suprapubic discomfort/tenderness, haematuria, passing foul-smelling urine.
• Exclusions: children, pregnant women, or with indwelling catheters (hyperlinked).
Typical pathogen profile
E.coli is the most common pathogen but a range of Gram negative and Gram positive bacteria may be responsible. Click to learn more.
Gram positive
Staphylococcus saprophyticus (5-10%)

Less commonly:
Klebsiella spp. 
Enterococcus spp. 
S. aureus 

Gram negative
E. coli (70-95%)
Proteus mirabilis (more rare)

Less commonly: Proteus vulgaris Enterobacter spp. Citrobacter spp. Serratia marcescens Acinetobacter spp. Pseudomonas spp. 

Yeast
Candida albicans – may be seen in patients with an indwelling, urinary catheter or men who are immunocompromised.
Microbiology investigations 
In primary care urine microscopy and culture are not routinely recommended for women with suspected uncomplicated UTIs because the results are not available for immediate decision-making and, by the time they are available, most women's symptoms will be resolving. Cultures should be obtained for men with suspected UTI. Click to read more detail.
• Do not routinely culture women < 65 years
• Men and women > 65 years with positive dipsticks – only culture if ≥ 2 symptoms of infection (especially dysuria, fever > 38.0⁰C or new incontinence).
• Culture - women with mild or ≤ 2 symptoms of UTI but with a urine dipstick positive for leucocytes and negative for nitrites, suspected UTI in men, suspected pyelonephritis, failed antibiotic treatment or persistent symptoms, patients with renal impairment (more likely to have a resistant strain), recurrent UTI, abnormalities of the genitourinary tract.

Evidence of infection
The presence of bacteria in the urine (bacteriuria) in a patient without other signs or symptoms is rarely an indication for antibiotic treatment. The prevalence of asymptomatic bacteriuria increases with increasing age in patients > 65 years old, but treatment may cause more harm (such as side effects of the medicine) than benefit. The decision to use antibiotics is primarily based upon the patient's signs and symptoms. Click to read more.
Start antibiotics in:
• Women with severe or ≥ 3 symptoms of UTI
• Women with mild or ≤ 2 symptoms of UTI and urine dipstick indicates infection
• Men with symptoms suggestive of UTI

Do not start antibiotics in:
 • Women with mild or ≤ 2 symptoms of UTI and urine is not cloudy, or urine dipstick does not indicate infection
 • Men and women >65 years with asymptomatic bacteriuria
Risk of antibiotic resistance
If resistance is suspected then a urine sample should be obtained and sent for culture and susceptibilities. Click here to read the risk factors for antibiotic resistance.
• Recurrent UTI (2 in 6 months, three or more in 12 months)
• Nursing home resident
 • Hospitalisation for more than 7 days in the last 6 months
• Unresolving urinary symptoms
• Travel to a country with increased antimicrobial resistance (outside Northern Europe and Australasia
• Previous UTI resistance to trimethoprim, cephalosporins or quinolones
• Renal impairment
Severity assessment
Be alert for the signs and symptoms of pyelonephritis (fever, loin pain) or sepsis (nausea, vomiting, confusion, tachypnoea, tachycardia, hypotension). Consider hospital admission.
Choosing an antibiotic
Please consult your local antibiotics guidelines for the preferred choice of agents. Click here to read the Public Health England (PHE) antibiotic guidelines for UTI (and other conditions) in primary care.
Follow up 
For women with uncomplicated lower UTI follow up is not routinely required. However women should be advised to seek medical attention if they develop loin pain or fever, or do not respond to first line antibiotics. Follow-up urine samples are not normally required. For men follow up should be arranged, for example after 48 hours, depending on clinical judgement to check response to antibiotic treatment and review urine culture results. 
Duration guide
• Women 3 days
• Men 7 days
• Fosfomycin – 3 gram single dose (PHE recommend a repeat [unlicensed] dose 3 days later in men)