UTIs Flashcards
How commonare UTIs in women or different ages?
30% of women have had a UTI by the age of 24 and 50% of women through their lifetime will have been treated for symptomatic UTIs.
Why are UTIs important to catch and treat?
It is a common source of Gram-negative septicaemia.
What host factors increases the chance of getting a UTI
- Shorter Urethra – more infections in females
- Obstruction – enlarged prostate, pregnancy, stones and tumours
- Neurological Problems – incomplete emptying, residual urine
- Ureteric reflux – ascending infection from bladder especially in children – defective valves allowing urine to flow back up into the bladder
What bacterial factors increases the chance of getting a UTI
- Fimbriae – allow attachment to host epithelium
- Haemolysins damage host membrane and cause renal damage
- K antigen permits production of polysaccharide capsule
- Urease breaks down urea creating a favourable environment for bacteria growth
What are the 3 most common bacteria causing UTIs
By far the most common are the coliforms type bacteria i.e. E.Coli gram negative rods. Following this is Proteus spp. and enterococci.
What clinical syndromes can occur due to UTIs
- Cystitis – lower UTI (bladder infection)
- Acute Pyelonephritis is an upper UTI and very rarely develops into chronic pyelonephritis.
- Asymptomatic bacterium e.g. in pregnancy can be dangerous for both mother and baby
- Septicaemia +/- shock
What symtpoms and signs does cystitis cause?
Dysuria (pain when passing urine), increased frequency, Urgency, burning pain when passing urine and sometimes low grade fever.
What symptoms and signs does pyelonephritis cause?
Fever, loin pain and may have dysuria and increase frequency.
What is an uncomplicated UTI?
Uncomplicated UTI is defined as infection by a usual organism in a patient with a normal urinary tract and normal urinary function. Uncomplicated infections may occur in (males) and female of any age.
What are complicated UTIs
Complicated UTI is when one or more factors are present that predispose the person to persistent infection, recurrent infection or treatment failure such as: Abnormal urinary tract, abnormal virulent organisms, impaired host defences (poorly controlled diabetes etc.) and impaired renal function.
How does investigating differ in UTIs depending on who the person is?
In healthy non-pregnant women of child bearing age (uncomplicated UTI) no need to culture the urine. However, you would culture the urine if it is deemed to be a complicated UTI i.e. in pregnancy, treatment failure, recurrent infection, suspected pyelonephritis, male or children.
How do we collect a specimen for investigation?
MSU (mid-stream urine collection), collection bag (20% false positive due to bacterium from skin), catheter sample, suprapubic aspiration and must make sure the urine is transported quickly and at a temperature of 4 degrees with or without boric acid.
What test can be performed on the specimen before it is sent to the labs?
Before sending to the lab can do a screening (near patient testing). Do a dipstick test that tests for leucocytes esterase (effectively testing for pus) and nitrite due to breakdown of nitrates by bacterium. We can also test for blood and proteins in the urine.
Also, inspect the urine visually for its turbidity. Normal urine should be clear whilst an abnormal urine will be slightly opaque.
When are/aren’t dipsticks useful?
Dipsticks are useful to exclude UTI in children under 3, men with mild/nonspecific symptoms and elderly women. It is not useful for acute uncomplicated UTIs in women, men with typical/severe symptoms, catheterised!!!! patients and older patients without features of infection.
What would you be looking for in urine under the microscope?
Looking for WBC and RBC, quite normal to see epithelial cells which may be covered in microorganisms normally present as flora in skin.
