UTIs Flashcards
What does the term ‘UTI’ represent?
A wide range of clinical syndromes.
Define bacteriuria.
The presence of bacteria in urine that does not necessarily imply infection.
What is asymptomatic bacteriuria?
Presence of bacteria in the urinary tract in the absence of symptoms.
In which patient populations is asymptomatic bacteriuria clinically significant?
- Pregnant women
- Patients undergoing invasive procedures of the urinary tract
What are normal mechanisms that maintain sterility of urine?
- Adequate urine volume
- Free-flow from kidneys through urinary meatus
- Complete bladder emptying
- Normal acidity of urine
- Peristaltic activity of ureters
- Increased intra-vesicular pressure preventing reflux
- In males, antibacterial effect of zinc in prostatic fluid
Classify UTIs based on location.
- Upper (pyelonephritis)
- Lower (cystitis and urethritis)
What are the classifications of UTIs based on the condition of the urinary tract?
- Uncomplicated
- Complicated
Differentiate between acute, chronic, and recurring UTIs.
- Acute: sudden onset
- Chronic: symptoms persist over time
- Recurring: relapse or reinfection
What are the symptoms of cystitis?
- Dysuria
- Urinary frequency
- Urinary urgency
- Supra-pubic pain
- Hematuria
- Nocturia
- Bladder tenesmus
- Absence of vulvar or vaginal discharge or irritation
What is pyelonephritis?
Clinical diagnosis implying a more invasive infection, inflammation of the kidney and renal pelvis.
What are the systemic findings associated with pyelonephritis?
- Fever
- Flank pain
- Nausea
- Chills
- Malaise
- Headache
What defines uncomplicated UTIs?
Occurs in patients with normal genitourinary tracts, usually non-pregnant premenopausal women of childbearing age.
What defines complicated UTIs?
Involves structural or functional abnormality of the genitourinary tract.
What are the two types of recurrent infections?
- Relapse: recurrence of infection by the same organism
- Re-infection: recurrence of infection by a different organism
What is the primary route of infection for UTIs?
Ascending route of infection via the urethra.
List some risk factors for UTIs.
- Aging
- Female gender
- Male prostatic hypertrophy
- Urinary tract obstruction
- Impaired bladder innervation
- Hematogenous spread
What is the most commonly isolated pathogen in UTIs?
Escherichia coli (~70% of all UTIs).
What is the significance of adherence in uropathogenic E. coli?
Adherence is a major virulence factor.
What role do urease-producing organisms play in UTIs?
They increase urinary pH leading to crystal formation and struvite stone formation.
What are the typical pathogens associated with nosocomial UTIs?
- E. coli
- Pseudomonas
- Proteus
- Enterobacter
- Candida
- Enterococcus
What is the significance of urinalysis by dipstick testing?
Primarily detects nitrites and leukocytes produced by infection.
What defines significant bacteriuria in urine culture?
> 10^5 bacteria/ml (10^8/litre).
Describe the clean catch mid-stream specimen collection method.
Urethra cleaned, first void urine passed, mid-stream collected in sterile container.
What is the preferred method for specimen collection from indwelling catheters?
Obtain urine by inserting a needle into the catheter or through the diaphragm.
How should specimens be transported to the lab?
Sent as quickly as possible, refrigerated if not received within 1-2 hours.
What is empiric therapy in the context of UTIs?
Based on most probable pathogens and local rates of resistance.
What are typical treatment regimens for uncomplicated cystitis?
- Nitrofurantoin
- Fosfomycin
- TMP/SMX (if resistance <24%)
- Doxycycline (2nd line)
- Ciprofloxacin (3rd line)
What may complicate the treatment of UTIs?
Increasing resistance to oral first-line agents.
