14. UTI Flashcards
What is a common source of gram negative septicaemia?
UTI.
Name 3 factors which increase a patients risk of developing a UTI.
Shorter urethra (females).
Obstruction eg enlarged prostate, pregnancy, stones, tumours.
Neurological problems eg incomplete emptying, residual urine.
Ureteric reflux - valves not fully developed in children leading to backflow.
Name 2 bacterial virulence factors that can help them infect a patient causing a UTI.
Fimbriae allow attachment to host epithelium.
K antigen permits production of polysaccharide capsule.
Haemolysins damage host membrane and cause renal damage.
Urease breaks down urea creating a favourable environment for bacterial growth.
What is the most common microorganism causing UTI and what does it’s gram stain look like?
E. coli.
Gram negative bacilli.
What are the 5 different clinical syndrome related to UTI?
Cystitis - lower UTI. Acute pyelonephritis - upper UTI. Chronic pyelonephritis - repeated UTI. Asymptomatic bacteriuria - pregnancy. Septicaemia with or without shock.
Give 3 symptoms of cystitis.
Dysuria.
Frequency.
Urgency.
Sometimes low grade fever.
Give 2 symptoms of pyelonephritis.
Fever.
Loin pain.
May have dysuria and frequency.
What is the definition of an uncomplicated UTI?
Infection by a usual organism in a patient with a normal urinary tract and normal urinary function.
What is the definition of a complicated UTI?
UTI when one or more factors are present that predispose the person to persistent infection, recurrent infection or treatment failure.
Give 2 examples of complicated UTIs.
UTI with abnormal urinary tract eg indwelling catheter.
Virulent organism eg staph aureus.
Impaired host defences eg poorly controlled diabetes (optimises bacterial growth) or immunosuppression.
Impaired renal function.
Cases in children, men and pregnant women are investigated and managed as what type of UTI?
Complicated.
When would you do a urine culture if you suspected a UTI?
In complicated UTI.
How is an MSU transported?
4 degrees celcius in boric acid.
How would you visually inspect a urine sample for a UTI?
Look for turbidity.
When is dipstick testing in a suspected UTI useful?
Useful to exclude UTI in:
children older than 3 years, men with mild/non-specific symptoms, elderly/institutionalised women.
What would you see on a urine microscopy that would indicated that the urine is contaminated?
Squame epithelial cell.
What is significant bacteriuria?
The amount to bacteriuria needed to distinguish between asymptomatic females (where the sample has become contaminated) and females with pyelonephritis. >10^5 cfu/ml distinguishes bacteriuria from contamination.
In a symptomatic adult woman with a UTI, half will have significant bacteriuria. What will the other half have and what is it?
Urethral syndrome - low count bacteriuria, fastidious organisms, vaginal infection/inflammation, sexually transmitted pathogens causing urethritis, mechanical, physical, chemical causes.
In what UTIs would you do imaging of the urinary tract?
All children.
Septic patients to identify renal involvement.
Posterior urethral valves in males.
Vesicles-ureteric reflux in females.
Name 3 causes of sterile pyuria.
Antibiotics. Urethritis (chlamydia/gonorrhoea). Vaginal infection. Chemical inflammation. TB. Appendicitis. Fastidious organisms.
What is asymptomatic bacteriuria?
Bacteriuria, usually in elderly females, with associated pyuria but no other symptoms. Only needs treating in pregnancy and urological surgery.
How would you treat simple cystitis?
3 day course of trimethoprim.
When would you only treat a patient with a UTI shown with CSU?
If systemically unwell.
How would you treat a patient with complicated UTI?
5-7 day course of trimethoprim. Post treatment follow-up cultures in paediatric patients and pregnant women.
How would you treat a patient with pyelonephritis/septicaemia?
14 day course of co-amoxiclav.
When would you treat a patient with prophylaxis against UTIs? What would you use?
3 or more episodes in one year and no treatable underlying condition.
Trimethoprim single nightly dose.
Name 2 structural abnormalities that can cause UTIs in children.
Posterior urethral valves in boys.
Vesicoureteric reflux, with or without renal hypoplasia.
Duplex ureters.
What is vesicoureteric reflux?
Reflux of urine from the bladder to the kidneys via the ureters.
