Uti Flashcards
What are host factors that can end to uti
shorter
urethra more infections in females
obstruction
enlarged prostate, pregnancy, stones, tumours
neurological problems
incomplete emptying, residual urine, e.g. at night, organisms can multiply
ureteric reflux
ascending infection from bladder especially in children, If valves nto working, urnie forced back into kidneys
What are sites and causes of uti
a. PUJ: calculi
b. Ureter: calculi, Ca, retroperitoneal fibrosis
c. Bladder: Neuropathic bladder
d. VUJ: calculi
e. Bladder neck: hypertrophy
f. Prostate: BPH / Ca
g. Urethra: stricture
What are Pasternak factors that lead to infection
- Fimbriae allow attachment to host epithelium
- Haemolysins damage host membranes and cause renal damage
- K antigen permits production of polysaccharide capsule
- Urease breaks down urea creating a favourable environment for bacterial growth
What are teh clinical syndrome related to ui
Cystitis - frequency & dysuria (lower UTI)
acute pyelonephritis (upper UTI)
chronic pyelonephritis - some patients go on to have chronic infection
asymptomatic bacteriuria - generally not a problem clinically (e.g. pregnancy - bacteria may nonetheless go in to cause infection)
septiceamia +/- shock
What are the clinical symptoms and signs
Lower UTI (cystitis) – Dysuria – Frequency – Urgency – Sometimes low grade fever Upper UTI (pyelonephritis) – Fever – Loin pain - Usually unilateral pain near oen kidney – May have dysuria, frequency.
What is uncomplicated uti
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 & females of any age
What is complicated uti
UTI when one or more factors are present that predispose the person to persistent infection, recurrent infection, or treatment failure. Examples include UTI with:
Abnormal urinary tract (e.g., vesicoureteric reflux, indwelling catheter, etc).
Virulent organism (e.g. Staph. aureus).
Impaired host defences (e.g. poorly controlled diabetes, immunosuppression).
Impaired renal function.
Compare when uncomplicated and complicated it is occur
Infections in children and men and some cases of pyelonephritis may meet the definition of ‘uncomplicated’
BUT in practice most cases in children, men and pregnant women, are investigated and managed as ‘complicated’
Pyelonephritis also requires further investigations and longer treatment
Desrieb investogatio of uti
in healthy non pregnant women of child- bearing age (uncomplicated UTI) no need to culture urine culture urine in ‘complicated UTI’ ie pregnancy, treatment failure, recurrent infections, suspected pyelonephritis, complications, male, children.
Describe how specifics are collected
MSU - cleansing not required in women (Collect id stream - representative of urine already in bladder - 10-20ml)
clean catch in children - no antiseptic
collection bag (20% false positives)
catheter sample
supra-pubic aspiration
transportation: 40C +/- boric acid
A sample of the organimsis that are present in the organisms.
There are organisms in urethra, orifice, ureter, more oragamisms get in - these can multiply i a lot of time before it gets analyse.. this can affect results
Either refrigerate or preserve with boric acid - stops organisms multiplying
Describe near patient testing
Turbidity
Dipstick testing:
– leucocyte esterase
– nitrite (Nitrites are an indicator of bacterial activity producing nitrites - very good indicator of uti. But NOT ALL units produce. If present, likely to be, but nto always present)
– haematuria
– proteinuria.
Check for glucose, bilirubin, etc. But the top 2 in list are the most important
Significant haematuria an be seen readily. Proteinuria is nto a major marker of infection
Where are dipstick tests usefu and not usefu
Useful to EXCLUDE UTI
– in children >3yrs
– men with mild/non-specific symptoms
– Elderly/institutionalised women
NOT useful
– Acute uncomplicated UTI in women
– Men with typical/severe symptoms - Mc can be positive and negative
– Catheterised patients - Catheter - lwograde inflammatory process - bacteria will be present - finding organisms doesnt make a diagnosis
– Older patients without features of
infection (asymptomatic bacteriuria common)
Describe miscorspy
Ss
What adescribe screening in the laboratory
Detects white cells, red cells, bacteria and cast Partials the same shape and size as bacteria. Casts - cells within the urinary tract which form concrete minor plaster cast in upper urinary tract - accumulation of white cells and other organisms
Screening is a way of giving a rapid result - the nes of interest can thenn be sent for culturing?? Testing»???
Descrbe urine culture
1 plate for 4 specimens. 4 urines from 4 patients. This medium is an indicator - particular reactions produce different colours. Coliform = pink. Culled small but finit volume- want to see how many organisms are presents. Bottom left - a lot of organisms. Pop left , large numbers growing, here it is lactose, no coliform. Different romp of organisms. Bottom right= no organisms. Top right - small numbers of organisms - contaminant from collection of urine - no significant growth
What is significant bacteriuria
asymptomatic females compared with females with pyelonephritis
>105 cfu/ml distinguishes bacteriuria/contamination
single specimen 80% predictive
?role in cystitis, men, and children
Acute infecton - very large amounts of organisms present.. smaller number - more likely to be non significant
What is teh role of culture
Investigation of children, males and other ‘complicated’ infections
increased sensitivity (down to 102 cfu/ml)
epidemiology of isolates
susceptibility data
control of specimen quality
Want guidance on treating individual - but also need data on how to treat patents we havent examined. Need to refresh ideas on what is a good agent for uti. Some agents used before - now resistance has developed. Culture helps to determines where ther we have a property collectured sample. Squares, = contamination. Plus cells, organisms = diagnostic
What is sensitivity testing
Antibiotic disks places on agar with culture. Can measure zones and make a mathematical estimation - whether or not they are active
Describe the interpretation o culture reports
Clinical details symptoms previous antibiotics quality of specimen delays in culture microscopy (if available) organism(s) isolated If they have been given antibiotics - started treatment for suspected infection -. Does it look like uti or not? Or use findings in context of specific patient
What re teh findings in symptomatic adult women
50% significant bacteriuria eg E. coli
50% urethral syndrome
– low-count bacteriuria
– fastidious organisms
– vaginal infection/inflammation
– sexually-transmitted pathogens - urethritis
– mechanical, physical & chemical causes
Describe imaging of the urinary tract
considered in all children with UTI Valuable in septic patients to identify renal involvement Males: posterior urethral valves Females: vesico – ureteric reflux Ultrasound
Describe sterile Perugia
Antibiotics urethritis (chlamydia/gonococci) vaginal infection/inflammation chemical inflammation tuberculosis - bear in mind appendicitis ?fastidious organisms
Describe asymptomatic bacteria
High prevalence in older people especially elderly females
Generally have associated pyuria
– Hence will have ‘positive’ dip stick test
– Therefore do not ‘routinely’ dipstick/culture
Not associated with ↑risk of morbidity/mortality
Leads to unnecessary antibiotic treatment
Only requires action in pregnancy and urological surgery
Antibiotics can drive up resistance, - increasing the problem .
Do not five antibiotics
Dipstick: Leukocyte eateries positive if white cells
Concern with asymptomatic bacteria in pregnancy but others, only do it iii certain cases, if it will be helpful
How are uti treated
increase fluid intake - flushing procecss
address underlying disorders eg uncrontlled diabetes, enlarges prostate
3 day course for uncomplicated UTI
5-7 day course for complicated lower UTI ie, pregnant, male, underlying disorders
CSU: only treat if systemically unwell
