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Archives of Disease in Childhood, 1974, 49, 917.
Prevalence of urinary tract infection in children
of preschool age
ROSEMARY BOOTHMAN, M. LAIDLAW, and I. D. G. RICHARDS
From the Social Paediatric and Obstetric Research Unit, Department of Child Health, University of Glasgow,
and Health Department, Corporation of Glasgow, and Glasgow City Laboratory
Boothman, R., Laidlaw, M., and Richards, I. D. G. (1974). Archives of
Disease in Childhood, 49, 917. Prevalence of urinary tract infection in children
of preschool age. 1000 children between the ages of 3 months and 5 years were
screened for urinary tract infection using a dipslide technique. Significant or doubtful
cultures were obtained in 130%, the rate being highest (47 0%) in children below the age
of one year. Higher rates were obtained in girls (16%) than in boys (11 %). After
serial dipslide and urine examinations, 9 children were considered to have a urinary
tract infection. 2 had radiological abnormalities.
In view of the uncertainty regarding the effect of treatment on the long-term
prognosis of children with asymptomatic bacteriuria, it is suggested that the results of
controlled studies should be awaited before any recommendation is made concerning
the urinary screening of this age group.
In childhood the prevalence of urinary tract
infection is second only to infection of the respiratory tract (Kass, 1956; Riley, 1964) and, while
there is no evidence to suggest that untreated
bacteriuria in the adult produces progressive kidney
damage (Asscher, 1970), the sequelae of untreated
infection in children may be more serious. British
Medical Journal (1963) suggested that persistent
urinary tract infection in childhood often leads to
chronic atrophic pyelonephritis and renal failure.
The prevalence of urinary tract infection in
childhood has been studied in the neonate and in
schoolchildren (see Table I) but little attention
seems to have been paid to children of preschool
age. This paper records the findings of a study in
which 1000 Glasgow children between the ages of
3 nAonths and 5 years were screened for urinary tract
infection using a dipslide technique.
To distinguish between bacteriuria due to
contamination before or after the collection of urine
and bacteriuria due to the presence of bacteria in the
bladder urine, Kass (1956) introduced the concept
of 'significant bacteriuria'. The term applies to
the presence of more than 100,000 organisms/ml
urine, and it is now widely believed that this demarcation between infection and contamination holds
true with few exceptions (Asscher, 1970).
Received 9 May 1974.
1B
Methods
The children studied were between the ages of 3
months and 5 years, any with known handicapping
conditions being excluded. In order to obtain a reasonably representative cross-section of the population, three
groups were examined.
(1) Children attending local authority child health
clinics (335).
(2) Children attending day nurseries (628).
(3) A small group of children visited at home in the
course of a study of child development (37).
Urine was voided into a sterile disposable gallipot
without preliminary cleaning up; it was used to inoculate
an Oxoid dipslide which was then incubated overnight
at 37 °C in the City Laboratory. The slides were all read
by one observer (ML) against the standards published by
the manufacturers, the results being recorded as follows.
more than 100,000 organisms/ml.
Significant
10,000 to 100,000 organisms/ml.
Doubtful
less than 10,000 organisms/ml.
Negative
In the cases reported as having significant bacteriuria
or a doubtful growth, a further dipslide was obtained for
culture and the urine itself was examined microscopically
and cultured. No special cleaning up procedure was
used except in the case of 2 babies and 2 older children
who were not 'socially clean'. For every child in the
study the nursery school staff, clinic health visitors, or
parents were asked about symptoms suggestive of urinary
tract infection.
The following rules were adopted at the beginning of
the study. (1) After a significant culture, whenever
917
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Boothman, Laidlaw, and Richards
918
TABLE I
Prevalence of urinary tract infection in studies of neonates and schoolchildren
Prevalence of UTI
Reference
Age group
Boys* (°'
Neonates
Schoolchildren
Entrants
13-14 yr
O'Doherty (1968)
O'Brien et a!. (1968)
Lincoln and Winberg (1964)
Littlewood, Kite, and Kite (1969)
Kunin, Southall, and Paquin (1960)
Kunin, Zacha, and Paquin (1962)
Meadow, White, and Johnston (1969)
Mair (1973)
Asscher et al. (1973)
Savage et al. (1973)
Savage et al. (1973)
Girls* (°,)
2 2
(410)
0 0
(420)
2
2
0
0
0
0
(298)
0 4
0-3
0*9
1 1
1 0
2 5
1 7
1 6
0 7
(286)
Both sexes* (%)
0 1
7
3
0
04
0
2
(309)
(1647)
(4968)
(1096)
(960)
(1000)
(29J)
(1601)
(4910)
(1026)
(1205)
(8722)
(5217)
(1455)
*Numbers investigated in parentheses.
possible 3 negative cultures were sought before a child
discharged from the study. (2) After a doubtful
culture, one negative culture was required before a child
was discharged. (3) A diagnosis of urinary tract
infection was made when 3 dipslide cultures were
significant, or if there were persisting significant and
doubtful cultures. Children with the infection were
referred to the Renal Unit at the Royal Hospital for Sick
Children, Glasgow, for further investigation.
In order to ensure that the method was technically
reliable and that the results were being correctly recorded
two control studies were undertaken. In the first, urine
specimens from 220 children were examined by standard
laboratory methods and the results compared with the
dipslides. In the second, 230 duplicate slides were sent
to the Bacteriology Department of the Royal Hospital
for Sick Children for culture and examination.
was
Results
Validation of the method. The comparison of
dipslide and urine cultures from 220 children is
shown in Table II. Negative results were recorded
for 154 dipslides; 4 of the related urine cultures were
reported as significant and 2 as doubtful. Repeat
urine cultures from these 6 children were negative
and the initial false positive results are attributable
to a delay of several hours between voiding and
plating out the specimens. 35 dipslides were
reported as positive; 7 of the related urine cultures
were recorded as negative and repeat cultures were
also negative.
The comparison of dipslide cultures in the study
and control laboratories is shown in Table III.
187 slides were reported as negative in the study
laboratory; none of the duplicates from these
children was reported as significant by the control
laboratory and only 3 as doubtful. 19 were reported
as significant by the study laboratory; 17 of the
duplicate slides were reported by the control
laboratory as positive and two as doubtful.
Main results. Dipslide cultures from 545 boys
and 455 girls were examined. The results of the
initial cultures are shown in Table IV. Overall,
130" had significant or doubtful cultures but the
rate varied with the child's age, the highest rate
(47%) being in children below the age of one year.
The rate then decreased to 400 in children aged 4
years. With the exception of 4-year-old children,
girls had a higher rate of significant or doubtful
cultures than boys. Overall, 16% of girls had
significant or doubtful cultures and 11° 0, of boys;
this difference is significant (P <0 05), but none of
the age-specific sex differences is significant.
Details of the children with urinary tract infection
TABLE
II
Comparison of dipslide and urine cultures
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Prevalence of urinary tract infection in children of preschool age
919
TABLE III
Comparison of dipslide cultures in the study and control laboratories
Control Laboratory
Study Laboratory
No.
Significant
Doubtful
Negative
17
1
2
14
Negative
187
0
3
0
9
184
Total
230
18
19
193
Significant
Doubtful
19
24
TABLE IV
Sex and age distribution of initial dipslide cultures and cases of urinary tract infection
Age (yr) and sex of children
3/12
All ages
4+
3
2
1
M
F
M
F
M
F
M
F
M
F
M
F
4
1
10
9
3
9
11
9
46
11
12
38
6
15
185
11
11
146
6
4
149
8
6
124
3
3
93
0
1
66
30
32
483
39
33
383
Total
15
21
66
61
206
168
159
138
99
67
545
455
Percentage
33
57
30
38
10
13
6
10
6
1
11
16
0
4
1
0
2
0
0
0
0
6
Dipslide culture
Significant
Doubtful
Negative
aignificant
or
doubtful
Cases of UTI
Number
Percentage
5*6
3*9
are shown in Table V. The initial dipslide had
been significant in 8 and doubtful in one. At the
Renal Clinic, serial urine examinations failed to
confirm infection in Cases 4, 6, 7, and 9. It is
thought that Case 3 was infected and that the
changing urine pattern was due to administration
of antibiotics for a chest infection; 2 further
children (Cases 1 and 8) were given antibiotics by
their general practitioners because of suspected
urinary tract infection. 3 children had symptomsfeeding problems (Case 1), frequency, dysuria, and
abdominal pain (Case 8), and nocturnal enuresis
(Case 9). The intravenous pyelogram was normal
in these 3 children. Cases 1 and 8 were admitted
to hospital for treatment of urinary tract infection
and Case 4 for isotope renography. A duplex
kidney was found in one child (Case 2) and impaired
renal function, described as 'difficult to interpret',
in another (Case 4).
Discussion
The dipslide technique, introduced by Guttmann
and Naylor (1967), has been shown to be a useful
and reliable quantitative method in screening for
bacteriuria (Arneil, McAllister, and Kay, 1970,
I
0 5
4
8
I
11
34
47
2
0*0
0*0
13
3
0*9
1973; Arneil, 1972, 1973; Savage et al., 1973). The
control studies conducted as part of our investigation
confirm the reliability of this method. 13% of the
initial dipslides gave significant or doubtful cultures.
The rate decreased with age, and this trend may be
associated with the greater difficulty of obtaining
uncontaminated specimens in the earlier years. It
is estimated that if equal numbers had been screened
in each age group, the rate would have been approximately 20%.
Although we attempted to follow closely the rules
laid down at the start of the survey, in a small
number of instances we were unable to obtain 3
negative cultures before discharging a patient after
a significant result, or to obtain a negative after a
doubtful culture. Reasons for this include parental
anxiety and difficulty in tracing some children.
We believe that few, if any, cases of urinary tract
infection were missed as a result of incomplete
follow-up. Whether any cases of the intermittent
bacteriuria of early pyelonephritis (Gower et al.,
1968) are overlooked in a study such as this can be
determined only by an investigation in which serial
dipslide cultures are made over several months.
The prevalence of urinary tract infection in this
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Boothman, Laidlaw, and Richards
920
TABLE
Summary of 9 cases of
Age (mth)
Case no.
Sex
1
M
DisieSLanure
at initial
Dpslide (SL) and urine
screening(U)clue
3
2
M
9
3
M
13
4
M
15
5
M
17
6
M
19
7
F
21
8
F
35
9
F
35
SL
UR
SL
UR
SL
UR
SL
UR
DSSS
SNSS
SSS
-NS
SSNDDD
-NNDD
SDSSDS
-DSSDS
SL
UR
SL
UR
SL
UR
SL
UR
SL
UR
SSDDSS
-SDDSS
SDNSNNDDNS
-DNSNNDDNS
SSDS
-SDS
SNS
-NN
SSS
-NS
Organism
Esch. coli
Intravenous pyelogram
Normal
Esch. coli
Duplex right kidney
Esch. coli
Normal
Pseudomonzas, Esch. coli,
Esch. coli
Fullness in left pelvi-calycea
system; large postmicturi
tion bladder residue
Normal
Esch. coli
Normal
Esch. coli
Esch. coli
Large postmicturition
bladder residue
Normal
Proteus
Normal
Proteus
S, significant; N, negative; D, doubtful.
study (9/1000) falls between the rate recorded in
previous studies of neonates and schoolchildren
(Table I). However, it should be realized that the
number of children at different ages in our study
varied greatly, and we estimate that were there equal
numbers in each group, the overall prevalence would
be 2 2.o
Of the 9 children with urinary tract infection, 6
were boys and all were aged less than 3 years. This
higher prevalence among boys is in contrast to the
female excess of significant or doubtful cultures
obtained from the initial dipslides. A higher
frequency of infection in male neonates than in
females has often been recorded (e.g. Craig, 1935;
Neumann and Pryles, 1962; Stansfeld, 1966;
Bergstrom, 1972; Littlewood, 1972) and has been
attributed to a greater prevalence of congenital
abnormalities of the urinary tract in males (Hutchison, 1965) and to the mode of infection thought
usually to be blood-borne (Littlewood, 1972).
In contrast, the prevalence of bacteriuria in schoolchildren shows a marked excess among girls, and
Kunin (1968) has reported that the prevalence rises
steadily with age with an annual acquisition rate of
0 32o%. Mair (1973) found that 40o of children
with so called 'asymptomatic bacteriuria' in fact had
symptoms of urinary tract infection. In our study,
one child (Case 8) had such symptoms at the time
of the investigation and another child (Case 1) had
feeding problems; the remainder were symptom
free.
Radiographic abnormalities of the urinary tract
are often found in children with bacteriuria (Kunin
et al., 1960, 1962; Meadow et al., 1969; Asscher
et al., 1973; Mair, 1973; Savage et al., 1973).
Vesicoureteric reflux is a commonly reported defect
and Smellie and Normand (1968) have shown that in
such children an uncontrolled urinary tract infection
leads to impaired kidney growth and the development of renal scarring; reduction of the infection
results in improved kidney growth and prevents
further scarring. In our study only 2 of the 9
children investigated radiographically were found
to have renal abnormalities; one had a congenital
lesion and another had impaired renal function of
unknown cause. This low prevalence of kidney
defects may be due to the early age at which these
children were examined; it could be that renal
scarring and impaired growth are detected radiographically only after a longer exposure to infection.
It has been estimated by Kunin (1968) that 5%
of girls leaving school have had a urinary tract
infection, while Arneil (1973) and Savage et al.
(1973) suggest that the Scottish figure is likely to be
higher than this. Many of these children have
x-ray abnormalities of the urinary tract, and Kunin
(1971) and Arneil (1973) have both called for the
general introduction of screening of schoolgirls for
urinary tract infection. Meadow et al. (1969)
emphasized the need for careful long-term studies
before recommending screening on a national scale,
and the outcome of studies such as that of Asscher
et al. (1973) is awaited with interest.
Our investigations indicate that urinary screening
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921
Prevalence of urinary tract infection in children of preschool age
irinary
tract
infection
Micturatinlg
Remarks
cystogram
Treatment
Esch. coli
Proteus
Esch. coli
Nitrofurantoin
Atrioseptal defect
Esch. coli
Nitrofurantoin
Isotope renogram showed impaired function
of right kidney
Normal
Nil
Feeding problems; antibiotics prescribed by
GP after first dipslide
Normal
Normal
Urine at
renal climc
|
Normal
Frequency, dysuria, abdominal pain;
antibiotics prescribed by GP
Nocturnal enuresis
in children of preschool age would give a low yield of
cases of infection; their detection would lead to the
identification of only a small number of congenital
anatomical anomalies of the urinary tract. It is
uncertain how the long-term prognosis is affected
by treatment and we believe that the results of
controlled studies are required before any recommendation can be made regarding the screening of
this age group.
We thank all who participated in this study, the
children and their parents, and the day nursery and clinic
staffs who collected the specimens; Dr. T. McAllister
and his staff for examining the duplicate dipslides and
the technical staff of the City Laboratory; Professor G.
C. Arneil and Dr. Anna Murphy for investigating the
children with urinary tract infection, Professor J. H.
Hutchison for helpful advice, and Miss M. Tinning for
clerical assistance.
The work of the Social Paediatric and Obstetric
Research Unit is supported by a grant from the Scottish
Home and Health Department.
R-EFRENCES
Arneil, G. C. (1972). Urinary tract infection in children. Update,
5, 1115.
Arneil, G. C. (1973). Latent urinary tract infection in schoolchildren. Scottish Medical_Journal, 18, 33.
Arneil, G. C., McAllister, T. A., and Kay, P. (1970). Detection of
bacteriuria at room-temperature. Lancet, 1, 119.
Ameil, G. C., McAllister, T. A., and Kay, P. (1973). Measurement
of bacteriuria by plane dipslide culture. Lancet, 1, 94.
Asscher, A. W. (1970). The Early Diagnosis of Urinary Tract
Infection. Early Diagnosis Paper 8. Office of Health Economics, London.
Asscher, A. W., McLachlan, M. S. F., Jones, R. V., Meller, S.,
Sussman, M., Harrison, S., Johnston, H. H., Sleight, G., and
Fletcher, E. W. (1973). Screening for asymptomatic urinarytract infection in schoolgirls. Lancet, 2, 1.
Sulphadimidine
Protetus
Sulphadimidine
Normal
Nil
Normal
Nil
Esch. coli
Nalidixic acid
Normal
Nil
Bergstrom, T. (1972). Sex difference in childhood urinary tract
infection. Archives of Disease in Childhood, 47, 227.
British Medical_Journal (1963). Renal transplantation, 1, 69.
Craig, W. S. (1935). Urinary disorders occurring in the neonatal
period. Archives of Disease Childhood, 10, 337.
Gower, P. E., Haswell, B., Sidaway, M. E., and de Wardener, H. E.
(1968). Follow-up of 164 patients with bacteriuria of pregnancy. Lancet, 1, 990.
Guttmann, D., and Naylor, G. R. E. (1967). Dip-slide: an aid to
quantitative urine culture in general practice. British Medical
Journal, 3, 343.
Hutchison, J. H. (1965). Acute infections of the urinary tract in
childhood. Practitioner, 194, 338.
Kass, E. H. (1956). Asymptomatic infections of the urinary tract.
Transactions of the Association of American Physicians, 69, 56.
Kunin, C. M. (1968). Emergence of bacteriuria, proteinuria, and
symptomatic urinary tract infections among a population of
school girls. Pediatrics, 41, 968.
Kunin, C. M. (1971). Epidemiology and natural history of urinary
tract infection in school age children. Pediatric Clinics of North
America, 18, 509.
Kunin, C. M., Southall, I.. and Paquin, A. J. (1960). The epidemiology of urinary-tract infections-a pilot study of 3057 school
children. New England Journal of Medicine, 263, 817.
Kunin, C. M., Zacha, E., and Paquin, A. J. (1962). Urinary-tract
infections in schoolchildren. I. Prevalence of bacteriuria and
associated urological findings. New England J7ournal of
Medicine, 266, 1287.
Lincoln, K., and Winberg, J. (1964). Studies of urinary tract
infections in infancy and childhood. II. Quantitative estimation
of bacteriuria in unselected neonates with special reference to
the occurrence of asymptomatic infections. Acta Paediatrica,
53, 307.
Littlewood, J. M. (1972). 66 infants with urinary tract infection in
first month of life. Archives of Disease in Childhood, 47, 218.
Littlewood, J. M., Kite, P., and Kite, B. A. (1969). Incidence of
neonatal urinary tract infection. Archives of Disease in Childhood, 44, 617.
Mair, M. I. (1973). High incidence of 'asymptomatic' urinary tract
infection in infant schoolgirls. Scottish Medical,Journal, 18, 51.
Meadow, S. R., White, R. H. R., and Johnston, N. M. (1969).
Prevalence of symptomless urinary tract disease in Birmingham
schoolchildren. I. Pyuria and bacteriuria. British Medical
Journal, 3, 81.
Neumann, G. C., and Pryles, C. V. (1962). Pyelonephritis in infants
and children. AmericanJournal of Diseases of Children, 104,215.
Downloaded from http://adc.bmj.com/ on June 16, 2017 - Published by group.bmj.com
922
Boothman, Laidlaw, and Richards
O'Brien, N. G., Carroll, R., Donovan, D. E., and Dundon, S. P.
(1968). Bacteriuria and leucocyte excretion in the newborn.
Journal of the Irish Medical Association, 61, 267.
O'Doherty, N. (1968). Urinary tract infection in the neonatal
period and later infancy. In Urinary Tract Infection, p. 113.
Ed. by F. O'Grady and W. Brumfitt. Oxford University Press,
London.
Riley, H. D. (1964). Pyelonephritis in infancy and childhood.
Pediatric Clinics of North America, 11, 731.
Savage, D. C. L., Wilson, M. I., McHardy, M., Dewar, D. A. E., and
Fee, W. M. (1973). Covert bacteriuria of childhood. A
clinical and epidemiological study. Archives of Disease in
Childhood, 48, 8.
Smellie, J. C., and Normand, I. C. S. (1968). Experience of follow-
up of children with urinary tract infection. In Urinary Tract
Infection, p. 123. Ed. by F. O'Grady and W. Brumfitt.
Oxford University Press, London.
Stansfeld, J. M. (1966). Clinical observations relating to incidence
and aetiology of urinary-tract infections in children. British
Medical.Journal, 1, 631.
Correspondence to Professor I. D. G. Richards,
Department of Community Medicine and General
Practice, University of Leeds, 32 Hyde Terrace, Leeds
LS2 9LN.
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Prevalence of urinary tract
infection in children of preschool
age
Rosemary Boothman, M. Laidlaw and I. D. G.
Richards
Arch Dis Child 1974 49: 917-922
doi: 10.1136/adc.49.12.917
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