What are some risk factors of UTIs | Age
Female
Catheters
Pregnancy
Diabetes
Immunocompromised
Shorter urethra
Sexual activity |
How do bacteria enter the Urinary Tract | Retrograde → ascending infection from the urethra
Via blood/lymphatics
Direct → catheter, surgery , instrumentation |
What are some bacterial virulence factors involved in infection of the UT | Adhesion – fimbriae and adhesins allow attachment to uroepithelium
K antigens – capsule resistant to phagocytosis |
What are some bacteria that cause uncomplicated UTIs | E.coli , Staphylococcus saprophyticus |
What are some natural defences | Low pH, high concentration of urea
Regular flushing – removes bacteria from distal urethra
Mucin layer
Antibacterial secretions by urothelium into the mucin layer
Inflammation & exfoliation of cells |
What are some common presentations | Dysuria
Frequency / Urgency
Haematuria
Incontinence
Cloudy/Offensive smelling urine
Pain |
What is urethral syndrome | About 50% of women who present with the clinical features of cystitis do not have positive urine cultures, a ‘urethral syndrome’
It could be an infection with low counts of bacteria
STIs
Non-infective inflammation e.g. chemical
Infection with fastidious organisms not detected on routine culture |
What does urine dipstick look for | Nitrites --> Nitrite produced by bacterial nitrate reductase when bacteria in contact with urine
Leucocytes |
What are some treatments for UTIs | Uncomplicated lower UTIs --> Short course of ABx (women 3 days, men 7 days) or delay and Nitrofurantoin (check eGFR) or Trimethoprim first line
Supportive measures --> fluids etc.
Always safety net
Guided by results of culture |
What is asymptomatic bacteruria | Common in elderly
Unless patient has symptoms , dont treat --> also if pregnant then treat
Does not reduce morbidity/mortality
Can lead to increase in antibiotic resistance |
What is the difference between reinfection and relapse | Reinfection --> Infection within 14 days but can be any organism while relapse is within 7 days and is the same organism
Relapse can be due to failure of treatment |
Difference between complicated and uncomplicated UTIs | Complicated: UTI with an increased likelihood of complications such as persistent infection, treatment failure and recurrent infection
Uncomplicated: UTI caused by typical pathogens in people with a normal urinary tract and kidney function, and no predisposing co-morbidities |
What are the different ways of taking urine cultures | Mid-stream Urine (MSU) sample preferred
Catheter technique
Pad sample |
When do you order a urine culture | Only if there is higher risk of complications e.g.
Pregnancy
Suspected pyelonephritis
Suspected UTI in men
Failed antibiotic treatment or recurrent symptoms
Recurrent UTI
It is not used routinely in uncomplicated UTIs |
What is treatment for UTIs | For uncomplicated lower UTIs then short course of antibiotics ( 3 days for women and 7 days for men )
Supportive measures
Guided by results of culture |