The diagnosis of urinary tract infection in infancy has significant
implications both in relation to initial management and the requirement
for subsequent potentially invasive investigation. The recent report by
Liaw et al (1) suggests that parental preference for collection of urine
specimens from infants would be for urinary pad (UPS) rather than clean
catch (CCU) or bag collection (BSU).
Although parental preference for UPS has been reported previously (2), it
is important to recognise that the accuracy of this technique in infants
is similar to that of BSU, with documented contamination rates of up to
68% (3). In addition, UPS has not been validated against the recognised
"gold-standard" of supra-pubic aspiration (SPA). In contrast, we have
recently reported that CCU is an accurate and reliable technique in direct
comparison to SPA (4). Indeed Liaw et al demonstrate a contamination rate
for CCU of 1/34, with no false positives. Unfortunately, the perception
that CCU collection is time consuming and inconvenient has limited its
widespread application but in our experience, and provided adequate
instruction and encouragement is given, parents are able to obtain a CCU
using a sterile bowl, in a median time of 15 - 17 minutes (5). We feel the
CCU technique is therefore applicable to both hospital and primary care
settings.
It is perhaps significant that Liaw et al stop short of advocating the use
of UPS in infants, and highlight the false positive rate associated with
this technique. We are concerned however that parental preference for UPS
will influence clinicians in adopting this technique and believe that if
parents were fully informed of the implications of a positive urine
culture in their infant, they would choose the most reliable technique for
urine collection and would not sacrifice accuracy for convenience.
1. Liaw LCT, Nayar DM, Pedler SJ, Coulthard MG. Home collection of
urine for culture from infants by three methods: survey of parents'
preferences and bacterial contamination rates. BMJ 2000;320:1312-1313.
2. Roderick E, Cox J. Nappy pads for collecting urine samples from
infants-pilot study. Br J Gen Pract
3. Macfarlane PI, Houghton C, Hughes C. Pad urine collection for
early childhood urinary-tract infection. Lancet 1999;354:571.
4. Ramage IJ, Chapman JC, Hollman AS, Elabassi M, McColl JH, Beattie
TJ. Accuracy of clean-catch urine collection in infancy. J Pediatr
1999;135:765-767.
5. McKune I. Catch or bag your specimen? Nursing times 1989;85:80-82.
Rapid Response:
Urine collection in infants
The diagnosis of urinary tract infection in infancy has significant
implications both in relation to initial management and the requirement
for subsequent potentially invasive investigation. The recent report by
Liaw et al (1) suggests that parental preference for collection of urine
specimens from infants would be for urinary pad (UPS) rather than clean
catch (CCU) or bag collection (BSU).
Although parental preference for UPS has been reported previously (2), it
is important to recognise that the accuracy of this technique in infants
is similar to that of BSU, with documented contamination rates of up to
68% (3). In addition, UPS has not been validated against the recognised
"gold-standard" of supra-pubic aspiration (SPA). In contrast, we have
recently reported that CCU is an accurate and reliable technique in direct
comparison to SPA (4). Indeed Liaw et al demonstrate a contamination rate
for CCU of 1/34, with no false positives. Unfortunately, the perception
that CCU collection is time consuming and inconvenient has limited its
widespread application but in our experience, and provided adequate
instruction and encouragement is given, parents are able to obtain a CCU
using a sterile bowl, in a median time of 15 - 17 minutes (5). We feel the
CCU technique is therefore applicable to both hospital and primary care
settings.
It is perhaps significant that Liaw et al stop short of advocating the use
of UPS in infants, and highlight the false positive rate associated with
this technique. We are concerned however that parental preference for UPS
will influence clinicians in adopting this technique and believe that if
parents were fully informed of the implications of a positive urine
culture in their infant, they would choose the most reliable technique for
urine collection and would not sacrifice accuracy for convenience.
1. Liaw LCT, Nayar DM, Pedler SJ, Coulthard MG. Home collection of
urine for culture from infants by three methods: survey of parents'
preferences and bacterial contamination rates. BMJ 2000;320:1312-1313.
2. Roderick E, Cox J. Nappy pads for collecting urine samples from
infants-pilot study. Br J Gen Pract
3. Macfarlane PI, Houghton C, Hughes C. Pad urine collection for
early childhood urinary-tract infection. Lancet 1999;354:571.
4. Ramage IJ, Chapman JC, Hollman AS, Elabassi M, McColl JH, Beattie
TJ. Accuracy of clean-catch urine collection in infancy. J Pediatr
1999;135:765-767.
5. McKune I. Catch or bag your specimen? Nursing times 1989;85:80-82.
Dr Ian J Ramage
Competing interests: No competing interests