Editor- Urinary tract infection is common and can lead to renal
scarring, especially in infants, but the collection of urine from small
children remains a problem. Liaw et al1 provide an interesting comparison
of urine collection methods and parents' preferences. We note their
report of the low contamination rate in clean catch urines far surpassing
that of the other methods, however they also report that parents disliked
clean catch collections and commented that their views should be heeded.
We have looked at the problem of urine collection in a somewhat different
way2. The clean catch method used by Laiw et al might well have been
more acceptable if the following points had been taken into account:
1. We have shown in a study of boys and girls that washing the
perineum does not make a significant difference to the contamination
rate2.
2. Clean catch urine collection does not need to be time consuming.
77% of children will produce a urine specimen within ten minutes if the
'finger tap' method is used one hour after a feed. The mean collection
time using this method is 5.5 minutes and the longest time twenty
minutes2. We recommend that if urine is not obtained within ten minutes
the attempt should be abandoned and a repeat attempt
made after the next feed. We would view a median collection time of
25 minutes as far too long. Long waiting times lead to loss of
concentration and missed specimens
Liaw et al have shown a contamination rate for pads of 22%, for bags of
27% and for clean catch of 3% when the nine samples growing >105
organisms (collection method not recorded) are excluded. The major
disadvantages of a contaminated specimen are the need to collect another
specimen and the waste of laboratory time and finance.
Liaw et al might find that the parental ranking of the clean catch method
improved if they used the 'finger tap' method with a ten minute time cut
off and ensured that collection was attempted one hour after a feed.
We were somewhat confused by the statement 'Parents found the pads and
bags easy to use and preferred them to clean catch collections for both
sexes' as only boys are mentioned as subjects in the study although at one
point there is reference to 'five children (four boys)' in relation to
suggested urinary tract infection.
1 Liaw LCT, Nayar DM, Pedler SJ, Coulthard MG. Home collection of
urine from infants by three methods: survey of parents' preferences and
bacterial contamination rates. BMJ 2000; 320: 1312 -3 (13 May)
2 Reduction in mixed growth rates in urine by using a "finger-tap"
method of collection Taylor MRH, Dillon M, Keane CT. BMJ 1986; 292 : 990.
Mervyn R. H. Taylor
Senior Lecturer & Consultant Paediatrician
Department of Paediatrics Trinity College Dublin,
National Children's Hospital,
(Adelaide & Meath Hospital Dublin incorporating the National
Children's Hospital)
Tallaght, Dublin 24, Ireland
C. T. Keane
Professor of Clinical Microbiology
Trinity College Dublin,
St. James's Hospital, James's St., Dublin 8 Ireland
Rapid Response:
"Finger tap" method of collection
Editor- Urinary tract infection is common and can lead to renal
scarring, especially in infants, but the collection of urine from small
children remains a problem. Liaw et al1 provide an interesting comparison
of urine collection methods and parents' preferences. We note their
report of the low contamination rate in clean catch urines far surpassing
that of the other methods, however they also report that parents disliked
clean catch collections and commented that their views should be heeded.
We have looked at the problem of urine collection in a somewhat different
way2. The clean catch method used by Laiw et al might well have been
more acceptable if the following points had been taken into account:
1. We have shown in a study of boys and girls that washing the
perineum does not make a significant difference to the contamination
rate2.
2. Clean catch urine collection does not need to be time consuming.
77% of children will produce a urine specimen within ten minutes if the
'finger tap' method is used one hour after a feed. The mean collection
time using this method is 5.5 minutes and the longest time twenty
minutes2. We recommend that if urine is not obtained within ten minutes
the attempt should be abandoned and a repeat attempt
made after the next feed. We would view a median collection time of
25 minutes as far too long. Long waiting times lead to loss of
concentration and missed specimens
Liaw et al have shown a contamination rate for pads of 22%, for bags of
27% and for clean catch of 3% when the nine samples growing >105
organisms (collection method not recorded) are excluded. The major
disadvantages of a contaminated specimen are the need to collect another
specimen and the waste of laboratory time and finance.
Liaw et al might find that the parental ranking of the clean catch method
improved if they used the 'finger tap' method with a ten minute time cut
off and ensured that collection was attempted one hour after a feed.
We were somewhat confused by the statement 'Parents found the pads and
bags easy to use and preferred them to clean catch collections for both
sexes' as only boys are mentioned as subjects in the study although at one
point there is reference to 'five children (four boys)' in relation to
suggested urinary tract infection.
1 Liaw LCT, Nayar DM, Pedler SJ, Coulthard MG. Home collection of
urine from infants by three methods: survey of parents' preferences and
bacterial contamination rates. BMJ 2000; 320: 1312 -3 (13 May)
2 Reduction in mixed growth rates in urine by using a "finger-tap"
method of collection Taylor MRH, Dillon M, Keane CT. BMJ 1986; 292 : 990.
Mervyn R. H. Taylor
Senior Lecturer & Consultant Paediatrician
Department of Paediatrics Trinity College Dublin,
National Children's Hospital,
(Adelaide & Meath Hospital Dublin incorporating the National
Children's Hospital)
Tallaght, Dublin 24, Ireland
C. T. Keane
Professor of Clinical Microbiology
Trinity College Dublin,
St. James's Hospital, James's St., Dublin 8 Ireland
Competing interests: No competing interests