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. Urinary Tract Infection. Urinary Tract Infection. Stages of life : Infancy Preschool
Stages of life :
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.
Characterised by significant bacteriuria, pyuria and sometimes haematuria.
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.
Care and insertion of Urethral Catheter :
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
Mostly Gram-negative bacilli
Other Gram negatives :
Gram-positive cocci :
Also yeasts (Candida species)
A significant bacteriuria (>100,000/ml) without symptoms - not treated except for at risk patients:
Predisposing factors :
Diagnosis as for UTI
Specimens are frequently contaminated with normal flora from perineum or genitalia.
Contamination reduced by taking ‘midstream urine’ specimens (MSU) having cleaned the genitalia
Collection methods :
NEVER by catheterisation
Must be transported rapidly to lab and refrigerated if delayed.
Use of transport kits have been recommended but often inhibitory to organisms
Interpretation of results for MSU:
1. >100,000 bacteria/ml urine – UTI
2. 10,000 bacteria/ml urine - usually either contamination or prior antibiotics
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)
Reasons for raised WCC cont’d:
Factors which facilitate ascent of organisms up the urethra :
Factors which result in the stagnation of urine in the bladder :
1. Increase fluid intake (= urine output)