1. Urinary Tract Infection
Very common
Significant cause of morbidity and mortality.
Occurs anywhere between the glomerulus and the external os of the urethra
Upper UTI is above the bladder
Lower UTI is from the bladder down

2. Urinary Tract Infection
Stages of life :
Infancy
Preschool
Honeymoon cystitis
Pregnancy
Prostatism

3. UTI - Who is susceptible?
Mostly females due to the (20cm) shorter urethra (30:1).
Exceptions are neonatal boys who are 4X more likely than neonatal girls to have an UTI – reasons not clear.
Elderly men become more susceptible due to prostatic hyperplasia but never overtake the females (2:1).
The one equalising factor is the urethral catheter.

4. UTI
Urinary tract and bladder are normally sterile apart from the anterior urethra which may be colonised with skin flora
Presence of microflora alone does not establish significance
Pyuria may or may not, reflect a response to infection

5. Urinary Tract Infection
Sterile Pyuria:
Renal TB Viral cystitis
Glomerulonephritis Prostatitis
Urethritis GU Fistula
Pelvic Abscess Stones
Schistosomiasis

6. UTI - Frequency and dysuria syndrome
Bacterial Cystitis
Characterised by significant bacteriuria, pyuria and sometimes haematuria.
Abacterial cystitis. Previously known as ‘urethral syndrome’. No bacteria are cultured from urine and the cause is usually unknown. (Often gut and vaginal anaerobes)

7. UTI
Infections are described as ‘uncomplicated’ as in most OPD or GP patients.
Or ‘complicated’ eg. in patients with congenital or surgical abnormalities of the tract or those having urological procedures and / or the presence of a urethral catheter.

8. UTI – Urinary Catheter

9. Hospital-Acquired UTI
Urinary catheter for relief of retention
Intermittent catheterisation following head or spinal cord injury, may be required several times a day.
Indwelling catheters - continuous drainage may be needed following spinal cord lesion or shorter term post TUR.
Any instrumentation or surgery on the urinary tract increases the chances of HA-UTI.

10. Hospital-Acquired UTI
Care and insertion of Urethral Catheter :
Motives?
Choice of catheter (smallest bore and balloon)
Insertion
Sterile procedure but NO disinfectant.
Bag emptying - maintain closed system.
Catheter toilet
Urine collection
Limit washouts and antibiotics.

11. UTI Almost all UTI’s are caused by organisms ascending the tract.
Few are caused by haematogenous transport of bacteria and other agents -
especially M. tuberculosis and Salmonella spp. Also rarely Schisto. haematobium,
Histoplasma and viruses such as CMV and Adenovirus

12. Recognised Urinary Pathogens
Mostly Gram-negative bacilli
Enterobacteriaceae
E. coli
Proteus spp
Klebsiella spp
Enterobacter spp
Citrobacter spp
Serratia spp
Providencia spp

13. Recognised Urinary Pathogens
Other Gram negatives :
Pseudomonadaceae
Pseudomonas spp
Alcaligenes spp
Gram-negative coccobacilli
Acinetobacter spp

14. Recognised Urinary Pathogens
Gram-positive cocci :
Micrococcaceae :
Staph saprophyticus
Staph aureus
Staph. epidermidis
Streptococcaceae :
Strep faecalis and other enterococci
Strep. agalactiae (Lancefield group B)
Also yeasts (Candida species)

15. UTI – Asymptomatic Bacteriuria
A significant bacteriuria (>100,000/ml) without symptoms - not treated except for at risk patients:
Pregnancy (To prevent acute Pyelonephritis)
Renal Disease diabetes or polycystic kidneys
The immunocompromised
Anatomical or neurological defects
Patients about to undergo urological examination
Children – require investigation for congenital reflux abnormalities

16. UTI – Acute Pyelonephritis
Predisposing factors :
Prostatic enlargement
Pregnancy (3rd Trimester)
Children with congenital malformations
Obstruction, calculi, tumours
Urethral catheterisation.
Diagnosis as for UTI

17. UTI – Lab. Diagnosis
Specimens are frequently contaminated with normal flora from perineum or genitalia.
Contamination reduced by taking ‘midstream urine’ specimens (MSU) having cleaned the genitalia

18. UTI – Lab. Diagnosis Collection methods : MSU/CSU Adhesive bags
Suprapubic stimulation (Babies)
Suprapubic aspiration
NEVER by catheterisation

19. UTI – Lab. Diagnosis
Must be transported rapidly to lab and refrigerated if delayed.
Use of transport kits have been recommended but often inhibitory to organisms

20. UTI – Lab. Diagnosis Interpretation of results for MSU:
1. >100,000 bacteria/ml urine – UTI
2. 10,000 bacteria/ml urine - usually either contamination or prior antibiotics
1,000 bacteria/ml urine – Usually contamination but may be significant with acute dysuria and frequency
More than one organism or mixed growth:
Contamination likely

21. UTI Factors affecting bacterial counts
Stage of infection
Fluid intake/ frequency of micturition.
Presence of antibiotics and other antibacterial substances (eg. Urea)
Underlying illness of the patient.
Whether patient is post-operative
The presence of a urinary catheter
Residual urine

22. UTI Factors affecting bacterial counts cont’d
Probably the age and sex of the patient
pH of urine
The growth rates of the organisms
The number of bacteria in a colony forming unit
The site of infection

23. UTI – Lab. Diagnosis
White cell count in urine is normally less than 10 white cells / cubic mm of urine.
Figures above this suggest an infection.
Though the WCC may be raised for other reasons eg :
Interstitial neuropathies (diabetes and analgesics)
Acute glomerulonephritis
Renal failure
Neoplasms

24. UTI – Lab. Diagnosis Reasons for raised WCC cont’d: Postoperative
Catheterisation
Fevers in children
Spread of inflammation of neighbouring sites (eg appendix or bowel)
White cells from preputial sac or vagina may contaminate the urine

25. UTI - Factors predisposing bladder to bacteruria
Factors which facilitate ascent of organisms up the urethra :
Urethral, bladder or prostatic surgery
Sexual intercourse
Vaginal prolapse

26. UTI - Factors predisposing bladder to bacteruria
Factors which result in the stagnation of urine in the bladder :
Infrequent micturition
Inadequate fluid intake (or urinary output)
Obstruction (Urethral valves, strictures, prostatic hypertrophy, constipation, calculi and catheters)
Vesico-ureteric reflux
Impairment of neurogical control of bladder
Bladder diverticula

27. UTI Treatment 1. Increase fluid intake (= urine output) Acidify urine
Antibiotics
Uncomplicated – 3 days
Pyelonephritis – days IV
Asymptomatic bacteriuria in pregnancy –
3-7 days