Infections of Kidney and Urinary Tract Flashcards
What is a UTI?
A urinary tract infection (UTI) is an infection of the kidneys, bladder, or urethra.
What is teh difference between an upper and lower UTI?
- Upper UTI: upperurinary tractcompriseskidneysand theureters(pyelonephritis)
- Lower UTI: lowerurinary tractcomprises thebladder(cystitis, the most common location of UTI),urethra(urethritis), andprostatein males (prostatitis)
What is urethral syndrome?
Urethral syndrome-irritation or inflammation of the lower UTI with no signs of bacteraemia or culture
RF?
Structure Sex Preg Post-menopause Chronic constipation Conditions-DM Intercourse Catheterisation
ddx?
Interstitial cystitis
- Symptoms have a gradual onset and last≥6 weeks(required for diagnosis).
- Painrelieved by voidingand worsened bybladderfilling (most common feature)
- Suprapubicpain, pressure, or discomfort
- Increasedurinaryurgencyand frequenc
Asymptomatic bacteriuria
Presence of≥ 100,000CFU/mLin at leasttwo voidedurinesamplesin patients withno symptoms ofUTI
Vaginitis
Discharge, irritation
PID
Pain, o urinary symptoms
Prostatitis
thismay present with feverish illness of sudden onset, symptoms of prostatitis (low back, suprapubic, perineal, or sometimes rectal pain), symptoms of UTI (dysuria, frequency, urgency or retention), or exquisitely tender prostate on rectal examination.
Urethritis and STI
suspect when there is dysuria, frequency, or urethral discharge, if the man is sexually active or at risk of a sexually transmitted infection
TB/drug/haemorrhagic cystitis
some drugs such as cyclophosphamide, opioids, and nifedipine can cause urinary tract symptoms, recurrent voiding symptoms or sterile pyuria.
Trauma
genitourinary procedures, sexual intercourse, sexual abuse or physical activity (such as cycling).
Structural abnormalities
Recurrent UTI’s , scan
Bladder cancer
in addition to symptoms of UTI, there may be haematuria
Obstructions
Recurrent UTI’s scan
Epidemiology?
Age: Older
Sex: Females
Ethnicity:
P:
Aetiology?
• Causative organisms
• Escherichia coli: leading cause of UTI (approx. 80%)[1]
• Staphylococcus saprophyticus:2ndleadingcause of UTI in sexually active women
• Klebsiella pneumoniae:3rdleadingcause of UTI
• Proteusmirabilis
○ Producesammonia, giving theurinea pungent or irritatingsmell
○ Associated withstruvite stoneformation
• Nosocomialbacteria:Serratia marcescens,Enterococcispp., andPseudomonas aeruginosaare associated with increased drug resistance.
• Enterobacterspecies
• Ureaplasma urealyticum
Viruses
• Immunocompromisedpatients and children are particularly susceptible to viral UTIs.[2]
• Adenovirus,cytomegalovirus, andBK virusare commonly involved inhemorrhagic cystitis.[3]
Other pathogens
• Yeast: rare (usuallyCandidaspecies)
• Abacterial:interstitial cystitis
CP-lower?
- Hematuria
- Increasedurinary frequency
- Urinary urgency
- Suprapubic tenderness
- Dysuria
CP-higher?
- Symptoms of lowerurinary tractinfection
- Fever
- Flankpain
- Fatigue/malaise
- Nausea and vomiting
additional CP?
• Male individuals:painin theprostatic/perineal area • Children[15] ○ Urinary incontinence ○ Malodorousurine ○ Irritability ○ Poor feeding ○ Failure to thrive • Elderly:delirium/acute confusion
Comapre CP of pyelonephritis, cystitis, and prostatitis
- Acute pyelonephritis:High fever, rigors, vomiting, loin pain and tenderness,(triad) oliguria (if acute kidney injury).
- •Cystitis:Frequency, dysuria, urgency, haematuria, suprapubic pain.
- •Prostatitis:Flu-like symptoms, low backache, few urinary symptoms, swollen or tender prostate onpr.
P?
- Women-shorter urethra-increased risk of UTI
- Main cause is bacterial-colonise in bladder, prostate or urethra
- Can move up towards upper urinary tract-pyelonephritis
- Bacteria contaminate tract due to risk factors and colonise certain regions of the tract
- This stimulates an inflammatory response-neutrophils are attracted to the site
- But bacteria have certain virulence factors that allow them to evade these and multiply
- Can also form biofilms-form groups and stick to each other and adhere to surfaces
- If treatment is not given or person is immunocompromised, then it ascends to the upper part
- Can also spread to the blood via renal arteries and so causes bacteraemia/sepsis
- Catheter- colonisation and immune response-neutrophils and fibrinogen accumulate-allow attachment of bacteria and can form biofilms, damage epithelial cells too
- Preg-progesterone causes smooth muscle relaxation-stasis-more likely to spread to the upper region-also more likely to be asymptomatic-more important to treat to prevent spreading to foetus
First line investigations?
urinalysis
Diagnostic criteria?
- Pyuria:≥ 5–10WBC/HPF
- Bacteriuria: abnormal number of bacteria present inurinesample (≥ 106organisms/mL)
- Positiveleukocyte esterase: an enzyme produced byWBCthatindicatespyuria
- Positivenitrites: indicates presence of bacteria that convertnitratestonitrites, which are most commonlygram-negative bacteria(e.g.,E.coli)
- Positiveurease: indicates presence ofurease-producing organisms(e.g.,Proteus,Klebsiella,S. saprophyticus), whichcause theurineto become more alkaline (pH> 7)
- Leukocytecasts will likely be absent with lower UTIs.
- Hematuriaand mildproteinuria
Urine culture?
GS
• Significantbacteriuria: defined as≥ 105CFU/mL; confirms the diagnosis
• The presence of any organisms in aurinespecimen obtained by suprapubicaspirationof thebladderconfirms the diagnosis.
