UTI Flashcards
What are the different areas you may get a UTI and what is the infection called in each area?
Kidney - acute/chronic pyelonephritis Bladder - cystitis Urethra - urethritis Prostate - prostatitis Epididymis/testis - epididymo-orchitis
What is the ratio of occurrence in females vs males?
F:M 3:1
What are the risk factors/causes of UTI? Including general features that may make a person more susceptible to infections in general
Stasis of urine
Pushing bacteria up urethra from below
Generalised predisposition to infection
Stasis
- obstruction (congenital or acquired)
- loss of feeling of full bladder (SCI/brain injury)
Pushing bacteria up
- sexual activity in females
- catheterisation
General factors which make an individual more susceptible to UTI or other infection)
- immunosuppression
- steroids
- malnutrition
- diabetes
Other causes
- Female sex (short urethra)
- Oestrogen deficiencies in post-menopausal women
- Fistula between bladder and bowel
What organisms are often responsible for UTI? What are uncommon pathogens?
Usually bowel organisms (gram-negative)
- E. coli (70-90%), proteus, klebsiella, enterococcus
Uncommon causes of UTIs
- Tuberculosis
- Schistosomiasis
What are the symptoms/signs of UTI in adults and children?
Adults
- flank pain
- dysuria (like passing broken glass)
- cloudy offensive urine
- urgency
- chills
- strangury
- confusion (elderly)
Children
- diarrhoea
- excessive crying
- fever
- nausea and vomiting
- not eating
What are the symptoms of acute pyelonephritis?
Pyrexia Poor localisation Loin tenderness (renal angle) Signs of dehydration Turbid urine
What investigations might be done in suspected UTI?
MSSU/CSU
lower tract - flow studies, residual bladder scan, cystoscopy
Urinalysis in ward - blood, leucocytes, protein, nitrites
upper tract - USS kidneys, IVU/CT-KUB, MAG-3 renogram, DMSA scan
Diagnosis requires microbiological evidence and symptoms/signs
- i - microbiological evidence - bacterial count of 104cfu/mL from MSSU specimen with no more than two species of micro-organisms (urine culture)
- ii - symptoms/signs - at least one
What level of bacteria in the urine is considered bacteruria?
How does it correlate with illness?
> 10^5
But depends on clinical symptoms
Can be asymptomatic
Bacteruria of pregnancy - 30% progress to symptomatic illness
When might you consider a diagnosis of reflux nephropathy? How do you confirm and treat it?
UTIs in children
Damage is caused by reflux + infection
Micturating cystogram (radionuclide 99Tc techniques)
Assess progression by USS and biochemistry
Surgery
How is UTI treated?
Principles
- identify infecting organism and institute appropriate treatment
- identify predisposing factors and treat if possible
Treatment
- fluids
- antibiotics - amoxicillin, cephalosporin, trimethoprim, IV in severe infections
What advice should be given to people with recurrent UTIs?
Fluid intake 2L/day
Void every 2-3 hours
Void before bedtime and before/after intercourse
What can recurrent/prolonged UTIs cause?
How is diagnosed, what are the signs, what is the prognosis?
Chronic Pyelonephritis
Radiological diagnosis Scarring and clubbing Hypertension/CRF ?Reflux 15% progress to renal failure
How do pathogens end up in the urinary tract?
Transurethral route
Bloodstream
Lymphatics
Transurethral
- periurethral area contaminated - recurrent UTIs, diaphragms
- urethra to bladder - intercourse, catheterisation
- bladder (and up ureters)
Route of infection almost always ascending
i.e. kidney infection spread from bladder
Why does obstruction lead to infection?
Slowed urine flow - cannot flush out bacteria
Sediments form > calculous formation (further obstruction + infection)
What are some common causes of urinary tract obstruction leading to infection?
Men - benign prostatic hyperplasia
Women - uterine prolapse
Both - tumours and calculi
