The factors associated with asymptomatic carriage of Helicobacter pylori in children and their mothers living in three socio-economic settings.
ABSTRACT The number of children infected by Helicobacter pylori is increasing worldwide. The aim of this study is to identify demographic and maternal risk factors affecting H. pylori positivity in asymptomatic children. One hundred sixty-five asymptomatic children, 75 (45%) females, and 90 (55%) males, between 2 and 12 years of age (mean 6.8 -/+ 3.0 years) were tested for the presence of H. pylori stool antigen. The ages, genders, weights, heights, and breastfeeding histories of the children were reported. Information concerning the age and education levels of the mothers, number of siblings, and family incomes was also taken. H. pylori stool antigen positivity was 30.9% (n=51) of the children and 30.4% (n=48) of their mothers. H. pylori positivity was detected in 70.6% (36) of children whose mothers were positive (P<0.001, r=0.64). Lower education level of mothers, lower family income, poor living conditions, and higher numbers of siblings were correlated with higher H. pylori positivity in children. The children living in the worst conditions and having less well educated mothers were at higher risk for H. pylori infection. The best way to decrease the prevalence of H. pylori infection in children is to educate women about how to protect themselves and their offspring from H. pylori infection.
- SourceAvailable from: Marta Granström[show abstract] [hide abstract]
ABSTRACT: Helicobacter pylori infection is mainly acquired in early childhood, but the exact routes of transmission remain elusive. To distinguish between risks of intrafamilial and extraneous child-to-child transmission, we studied H. pylori seroprevalence among Swedish school children with varying family backgrounds. In a cross-sectional study, 695 of 858 (81%) 10-12-year-olds in 36 school classes in Stockholm donated blood and answered a questionnaire. Infection was detected by enzyme-linked immunosorbent assay and confirmed by immunoblot and urea breath test. Overall, 112 (16%) children were infected. The seroprevalence was 2% among 435 children with Scandinavian parents and 55% among 144 children with origin in high prevalence areas (Middle East and Africa). Among children born in Scandinavia, the odds ratios (adjusted for gender, socioeconomic status, and family size) for being seropositive were 39.1 (95% confidence interval, 16.7-91.3) and 5.6 (1.8-17.3) when having parents born in high and medium prevalence areas, respectively, relative to children with Scandinavian parents. Importantly, the prevalence of infection among the classmates was not a risk factor for H. pylori infection. Our data indicate that intrafamilial transmission is far more important than child-to-child transmission outside the family. The H. pylori prevalence in the parental generation may be a crucial determinant for the child's risk of contracting the infection.Gastroenterology 08/2001; 121(2):310-6. · 12.82 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Biopsy specimens of the antrum and corpus were obtained from four Helicobacter pylori-infected members of a family and from the same boy (son 1) in whom the infection reappeared after simultaneous successful eradication treatment of three family members, excluding the mother. A total of 18 to 60 H. pylori isolates were obtained from each specimen and subjected to rRNA gene restriction pattern analysis. The father's isolates and the initial isolates from son 1 showed the same HindIII type, which was divided into three HaeIII subtypes. Isolates from the mother and a brother (son 2) and posttreatment isolates from son 1 showed a distinct HindIII type (with one minor subtype), which was divided into six HaeIII subtypes. All subtypes of the initial isolates from son 1 were present in the father's isolates, and all subtypes of the posttreatment isolates from son 1 were present in the mother's isolates but not in son 2's. Electron microscopic analysis of the biopsy specimens demonstrated extremely high levels of H. pylori colonization in the father's gastric mucosa. H. pylori adherence with a ruffle formation was also demonstrated. The findings suggest that son 1 was infected initially with the H. pylori strain of the father and son 2 was infected with the H. pylori strain of the mother and that after eradication therapy son 1 was reinfected with the H. pylori strain of the mother, who did not undergo eradication therapy.Clinical and Diagnostic Laboratory Immunology 08/2001; 8(4):731-9. · 2.51 Impact Factor
- BMJ 08/1999; · 14.09 Impact Factor
The Factors Associated with Asymptomatic Carriage of Helicobacter pylori
in Children and Their Mothers Living in Three Socio-Economic Settings
Oya Yücel*, Ayse Sayan1, and Mustafa Yildiz
Medical Faculty and 1School of Health, Sakarya University, Sakarya, Turkey
(Received April 25, 2008. Accepted January 19, 2009)
SUMMARY: The number of children infected by Helicobacter pylori is increasing worldwide. The aim of this
study is to identify demographic and maternal risk factors affecting H. pylori positivity in asymptomatic children.
One hundred sixty-five asymptomatic children, 75 (45%) females, and 90 (55%) males, between 2 and 12 years
of age (mean 6.8 ± 3.0 years) were tested for the presence of H. pylori stool antigen. The ages, genders, weights,
heights, and breastfeeding histories of the children were reported. Information concerning the age and education
levels of the mothers, number of siblings, and family incomes was also taken. H. pylori stool antigen positivity
was 30.9% (n = 51) of the children and 30.4% (n = 48) of their mothers. H. pylori positivity was detected in
70.6% (36) of children whose mothers were positive (P < 0.001, r = 0.64). Lower education level of mothers,
lower family income, poor living conditions, and higher numbers of siblings were correlated with higher H.
pylori positivity in children. The children living in the worst conditions and having less well educated mothers
were at higher risk for H. pylori infection. The best way to decrease the prevalence of H. pylori infection in
children is to educate women about how to protect themselves and their offspring from H. pylori infection.
Jpn. J. Infect. Dis., 62, 120-124, 2009
*Corresponding author: Mailing address: Kos ¸uyolu, Veysi Pas ¸a
Sok. 100. Yıl Sitesi, I-Blok, No:22, Üsküdar, ˙Istanbul, Turkey.
Tel & Fax: +90-264-2956602, +90-21-4114033, E-mail: oyayucel
Although Helicobacter pylori infection is common all over
the world, the time of acquisition is unclear. The prevalence
of H. pylori differs significantly both between and within
countries. The high risk of intrafamilial infection was shown
in some previous studies (1-3). It is believed that in the vast
majority of infected individuals, infection is acquired during
early childhood (1-5), and that the mother probably plays a
key role in transmission (2,6).
Because of limited data on the epidemiology of H. pylori
and its associated risk factors in Turkey, our aim was to iden-
tify maternal risk factors associated with the acquisition of
H. pylori in asymptomatic Turkish children and to determine
relationships with the age, number of siblings, education level,
living space, and breastfeeding. In this study, we were inter-
ested in the role of mothers in H. pylori transmission in
asymptomatic children living in the northern part of Turkey.
This study was the first study in the region.
MATERIALS AND METHODS
Study design: The study was cross-sectional in design.
One hundred sixty-five asymptomatic children between 2 and
12 years of age and their mothers were tested for H. pylori
infection with monoclonal antibodies to H. pylori stool anti-
gen (HpSA). Children on no medication for the previous
month were enrolled. Children were admitted to the study
after being volunteered by their mothers or fathers. None of
the mothers had previously taken any medication for H.
The age, gender, weight, height, breastfeeding history, and
HpSA test result of each child was recorded. Details on the
age of the child, number of the child’s siblings, family in-
come, whether the mother worked outside the home or not,
and the mother’s level of education were obtained from each
Data were collected from children belonging to families
with differences in education level, family income, and do-
mestic living space at three separate sites. The first site was
the outpatient clinic of a university medical center, and
samples were collected from subjects who included the chil-
dren of academic staff members (Group 1). The members of
this group were living inside the university and had a higher
socioeconomic status and family income than the members
of the other two groups. The second site was a public health
center located in the city center, serving a population of people
of moderate socioeconomic conditions (Group 2). The last
site was a public health center located in a suburb where most
inhabitants were poor and unemployed. This site served an
area of high socioeconomic deprivation, and the members of
this group (Group 3) had the poorest conditions of the three.
Mothers were categorized into one of four educational lev-
els: illiterate; completed only elementary school education
(age 11); completed high school education (age 18); and com-
pleted university education. The mothers in Group 1 were
educated to the high school or university level. Most mothers
in the second group were educated only to the elementary
school level, and mothers in the third group were mostly
illiterate. The results of the HpSA tests were compared with
information from each group to evaluate the risk factors for
H. pylori in children.
Questionnaires: Assessment of the participants’ health
status and social and demographic characteristics was based
on data from questionnaires. The questionnaires concerned
the age, gender, number of siblings, breastfeeding history of
the participant, mother’s age, education level, and whether
she worked at home or not, and family income. After re-
ceiving the necessary permission from the authorities of the
institution and local authorities, the data collection process
began. A questionnaire was filled out for each subject by us.
The study was conducted according to the principles of the
Declaration of Helsinki (1989). Informed consent was obtained
from all people questioned after full explanation of the study.
Written approval was obtained from the parents of the chil-
H. pylori analysis: Stool specimens were examined by a
one-step Helicobacter pylori antigen cassette test (Linear
Chemicals, S.L, Barcelona, Spain) for the presence of H.
pylori. This test was a qualitative immunochromatographic
assay using monoclonal antibodies. The test cassettes in the
preapplication period were stored between 4°C and 8°C dur-
ing the study. The HpSA tests were performed according to
the manufacturer’s instructions on fresh stool samples. The
results were evaluated within 10 min and any sample whose
test-line changed color was interpreted as a positive.
Statistical analysis: Statistical analysis was performed
using SPSS for Windows version 12.0 (SPSS Inc., Chicago,
Ill., USA). Data was presented as mean ± SD. The obtained
results were assessed by independent t-samples test and
ANOVA. Correlations were calculated with the Pearson test.
P < 0.05 was considered statistically significant.
One hundred sixty-five children and their mothers were
included in this study. The children’s average age was 6.8 ±
3.0 years, average weight was 22.2 ± 8.9 kg, and average
height was 1.16 ± 0.2 m. Seventy-five (45%) of them were
girls and 90 (55%) were boys. Fifty-one (30.9%) of the chil-
dren were found to be HpSA positive and 114 (69.1%) were
negative. The difference in the positivity of H. pylori between
males and females was not significant (P = 0.46). HpSA posi-
tivity was found in 48 (30.4%) of the mothers. The age of the
mothers ranged from 22 to 45 years (mean age 33.1 ± 5.2
years). The incidence of H. pylori positivity among mothers
of H. pylori-positive children was found to be 70.6% (36/51)
(Table 1). A statistically significant positive correlation be-
tween H. pylori-positive children and the positivity of their
mothers was demonstrated (P < 0.001, r = 0.64). The incidence
of HpSA positivity in the children of Group 3 was 58.3% (35/
60). This percentage fell to 17% (14/82) in Group 2 (city cen-
ter), and to 8.7% (2/23) in Group 1 (academic staff members’
children). When the HpSA status of the mothers of the chil-
dren was evaluated, 55% (33/60) of the mothers in Group 3,
15.9% (13/82) of the mothers in Group 2, and 8.7% (2/23) of
the mothers in Group 1 tested positive. A statistically signifi-
cant difference was determined between Group 3 and Group
1 according to the H. pylori positivity of children and their
mothers (P < 0.001; 95% confidence interval [CI], –0.83528
There was no statistically significant correlation in H.
pylori positivity in children with the age of the mothers or
the children (P = 0.08; P = 0.07). The relationship between
the education levels of the mothers and H. pylori positivity
of their children is also shown in Table 2 and Figure 1. A
statistical correlation was found between the duration of
breastfeeding and H. pylori positivity, but it was not signifi-
cant (P = 0.02; 95% CI, 0.517-7.349; r = –0.18).
Of the children, 10 had never breastfed, and their HpSA
positivity ratio was found to be 30% (3/10). Eighty-one chil-
dren (49.1%) had breastfed in the first 6 months, and HpSA
positivity was determined in 13 of them (16%). In the children
Fig. 1. Distribution of education levels of the mothers having H. pylori
stool antigen positivity among groups.
Fig. 2. Relationship between H. pylori-positivite subjects and breastfeeding
according to the groups.
Table 2. Relationship between education level and H. pylori positivity
HpSA (+)HpSA (–)
No. (%)No. (%)No. (%)
IIliterate22 (44) 18 (16)0 40 (24)
Primary school 24 (52) 62 (57)4 90 (54)
High school 2 (4) 21 (20)2 25 (15.5)
University 0 9 (7)1 10 (6.5)
Total48 1107 165
Table 3. Statistical analysis of the factors associated with HpSA
positivity in asymptomatic children and their mothers
Mother HpSA (+)< 0.0010.762/–0.5190.64
No. of siblings< 0.0011.031/1.890
Mother education < 0.001
Family income < 0.001
Living space < 0.001
Table 1. Comparison of the relationship H. pylori positivity between
mothers and children
HpSA (+) childrenHpSA (–) childrenTotal
HpSA (+) mothers 36 12 48
HpSA (–) mothers 12 98 110
Total 48 110158
HpSA, H. pylori stool antigen.
who had breastfed for 12 months, the HpSA positivity ratio
was 65.4% (17/26), and this ratio for those who had breastfed
for more than 12 months was 37.5% (18/48) (Figure 2).
The number of siblings in the families varied from 1 to 7.
The mean number of siblings was found to be 2.2 ± 1.4, and a
positive correlation was determined between H. pylori posi-
tivity and the number of siblings (P < 0.001, r = –0.04). The
lowest ratio of H. pylori positivity was found in mothers with
one child. The incidence of H. pylori positivity increased with
family size. The distributions of HpSA positivity among chil-
dren according to the number of children who lived in the
same home are presented in Figure 3. Statistical parameters
are shown in Table 3, and all data in Table 4.
Fig. 3. Distribution of H. pylori positivity among groups according to
the number of children living at same home.
Fig. 4. Relationship between H. pylori positivity and the ages of chil-
dren according to the groups.
Table 4. Analysis of factors associated with H. pylori infection
Helicobacter (+)Helicobacter (–)
Total Group 1Group 2Group 3Total Group 1Group 2Group 3
No. (%)(n = 2)(n = 14)(n = 35)No. (%)(n = 21)(n = 68)(n = 25)
Children 16551 (30.9) 114 (69.1)
Mothers15848 (30.4) 110 (69.6)
Female 75 (45)21 (41.2) 2 (100) 4 (28.5)15 (42.8) 54 (47.4) 9 (42.8)35 (51.5) 10 (40)
Male 90 (55)30 (58.8)0 0 (71.4)20 (57.1) 60 (52.6)12 (57.1)33 (48.5) 15 (60)
2-4 y 44 (26.6) 13 (25.4)0 3 (21.4)10 (28.6) 31 (27.4) 1 (4.8)25 (36.7) 5 (20)
5-6 y 34 (20.6) 7 (13.7)0 2 (14.2) 5 (14.2) 27 (23.6) 8 (38)14 (20.5) 5 (20)
7-8 y 36 (21.9)12 (23.5) 1 (50) 4 (28.4) 7 (20) 24 (20.8) 5 (23.8)11 (16.1) 8 (32)
9-10 y 27 (16.4) 6 (11.7) 1 (50) 1 (7.1) 4 (11.4) 21 (18.4) 3 (14.2) 4 (20.5) 4 (16)
11-12 y 24 (14.5)13 (25.4)0 4 (28.4) 9 (25.7) 11 (9.6) 4 (19) 4 (5.9) 3 (12)
No. of siblings
1 56 (33.9) 7 (13.7)1 (50) 3 (21.4) 3 (8.5) 49 (87.5)10 (47.6)34 (50) 5 (20)
2 60 (36.4)15 (29.4) 1 (50) 9 (64.3) 5 (14.2) 45 (75) 9 (42.8)33 (48.5) 3 (12)
3 20 (12.1) 9 (17.6)0 2 (14.2) 7 (20) 11 (55) 0 1 (1.5)10 (40)
4 16 (9.6) 9 (17.6)0 0 9 (25.7) 7 (43.7) 2 (9.6) 0 5 (20)
5 5 (3.0) 3 (5.9)0 0 3 (8.5) 2 (40) 0 0 2 (8)
6 4 (2.4) 4 (7.8)0 0 4 (11.4) 0 0 0 0
7 4 (2.4) 4 (7.8)0 0 4 (11.4) 0 0 0 0
Age of mothers
20-30 49 (29.6)10 (19.6)0 3 (21.4) 7 (20) 39 (34.2) 7 (33.3)26 (38.2) 6 (24)
31-40 101 (61.2)35 (68.6) 2 (100)11 (78.5) 22 (62.8) 66 (57.8) 13 (61.9)35 (51.5)18 (72)
>40 15 (9.1) 6 (11.8)0 0 6 (17.1) 9 (7.9) 1 (4.8) 7 (10.3) 1 (4)
None 10 (6) 3 (5.8)0 0 3 (8.7) 7 (6.1) 2 (9.6) 1 (1.5) 3 (12)
0-6 m 81 (49.1)13 (25.5)010 (71.4) 3 (8.7) 68 (59.6) 9 (42.8)59 (86.5) 1 (4)
0-12 m 26 (15.7)17 (33.3) 2 (100) 4 (28.4)11 (31.4) 9 (7.9) 1 (4.8) 5 (7.5) 3 (12)
0-24 m 39 (23.7)14 (27.4)0 014 (40) 25 (21.9) 9 (42.8) 2 (3)14 (56)
0-48 m 9 (5.5) 4 (7.8 )0 0 4 (11.4) 5 (4.4) 0 1 (1.5) 4 (16)
Illiterate 40 (24.2) 22 (43.1)0 022 (62.8) 18 (15.7) 0 0 18 (72)
Primary school 90 (54.5) 26 (51)1 (50) 13 (92.8)12 (34.3) 64 (56.1)10 (47.6) 48 (70.5) 6 (24)
High school 25 (15.1) 3 (5.9)1 (50) 1 (7.2) 1 (2.9) 24 (68.6) 6 (28.6)16 (23.5) 0
University 10 (6.1) 00 0 0 10 (28.6) 5 (23.8) 4 (5.9) 1 (4)
The monoclonal H. pylori stool antigen test is an accurate,
non-invasive method for the initial diagnosis of H. pylori
infection (7,8). It is possible that children from developing
countries have higher bacterial loads and larger amounts of
H. pylori antigen in the stool. It has been reported that this
can improve the sensitivity of this test (9). In the analysis of
studies performed, pretreatment evaluation of the monoclonal
stool antigen test was presented that demonstrated a mean
sensitivity of 96% and a specificity of 97% (10). In asymp-
tomatic children, the specificities and sensitivities of the HpSA
test have been reported as 94 and 88.9%, respectively (11).
This is the main reason why the HpSA test was chosen for
Apart from its high sensitivity and specificity, the mono-
clonal HpSA test was also chosen for use in this study be-
cause of technical difficulties using the other non-invasive
tests in Group 3. For this reason, we did not use these other
tests as confirmation. An additional problem was that some
mothers refused to provide stool samples.
The positivity of H. pylori infection among mothers was
found to be 30.4%, and 30.9% in children. However, these
incidences were different in the three groups. The HpSA
positivities in children and mothers were the lowest in Group
1. The highest HpSA positivity in children was found in Group
3--68.6% (35/51). In Groups 2 and 1, this value was 27.5 and
3.9%, respectively. This result shows that higher income and
education levels of mothers and a more convenient living
space can reduce HpSA infection in children as well as in the
rest of their family. Several studies have shown that H. pylori
positivity is correlated with low socioeconomic status (12-
14). In a study from Turkey, an infection rate of 89% was
detected in a low socioeconomic group compared to 70% in
a middle level group and 41% in a high level group (15).
Socioeconomic status plays a significant role in the acquisi-
tion of H. pylori.
The influence of adult socioeconomic factors on preva-
lence of infection has been less well characterized. Wizla-
Derambure et al. (12) stated that the number of persons liv-
ing together was more important than socioeconomic status,
and the presence of the mother at home did not appear to
influence the rate of H. pylori infection in children. These
results are also supported by our study. None of our children
went to day-care centers, but were all taken care of at home.
Likewise, none of the mothers were working away from home,
except the Group 1 mothers. The HpSA positivity in the chil-
dren of Group 1 was 3.9%, the lowest rate among all groups.
This shows that mothers working outside do not facilitate
infection of children by H. pylori. In contrast, children living
with the mother at home all day are more susceptible to
infection by H. pylori. It was thus found that mother’s H.
pylori infection and close contact with her all day are the
main causes of contamination of children.
There was a strong association between the number of
siblings and the incidence of H. pylori infection among the
children in our study. Family size ranged from 3 to 4 in Group
1, from 4 to 6 in Group 2, and from 5 to 9 in Group 3. In our
study, the incidence of HpSA positivity increased with
increasing family size. It has been claimed that the most im-
portant socioeconomic and demographic factors associated
with H. pylori infection are an overcrowded family, parents’
lack of education and father’s occupation (12). Goodman
and Correa (13) pointed out that the strongest predictor of
H. pylori status was the number of children who lived at home.
Our results concur with these findings. The relationship be-
tween HpSA positivity and the number of siblings living in
the same home is presented in Figure 3.
In previous studies from Turkey, among asymptomatic
children, the prevalence of H. pylori infection was found to
be between 49.5 and 56.6% (15,16). In another study from
Turkey, it was 42.0% under 10 years of age (17). This value
was found to be 30.9% among all asymptomatic children in
our study. However, more than half of these children who
were H. pylori positive were under 7 and 8 years of age.
According to our findings, the HpSA test may be used in child-
hood as a screening test in the pretreatment period for the
general population. There was no significant relation between
the H. pylori positivity and rising age, but it was notable that
there were sharp increases in three age groups: between 2-4
years of age, 7-8, and 11-12 (Figure 4). This increase, how-
ever, could not be clearly explained by our findings.
H. pylori positivity in children and mothers was affected
by the mother’s level of education in our study. Group 3, which
contained mostly less well educated mothers and their chil-
dren, had considerably higher levels of infection when com-
pared with the other groups (68.6% versus 27.5% and 3.9%).
The children who had illiterate mothers also had an increased
prevalence of H. pylori infection compared with the children
who had well educated mothers. In contrast, the prevalence
of infection among the well educated mothers was extremely
low. The education levels of the mothers were affected by
socioeconomic conditions, as it was determined that illiterate
mothers were living in the deprivation area which we clas-
sified as Group 3. The education level of the mothers was
one of the most important factors affecting the H. pylori
positivity of children. The rate of H. pylori infection among
children having well educated mothers was extremely rare.
These results are presented in Figure 1. In another study from
our population, Abasiyanik et al. (17) could not show any
relationship between education levels and H. pylori infection,
in contrast to our data. In our study, very different regions
were chosen in order to determine and emphasize educational
and socioeconomic differences. However, in Abasiyanik’s
study, the subjects were randomly chosen within a homog-
enous society (a city center). The reason why educational dif-
ference was not determined in the Abasiyanik et al. (17) study
may be because these researchers did not classify the study
Several studies have investigated the association between
H. pylori and breastfeeding with conflicting results. Some
studies on the effect of breastfeeding have pointed out that it
did not protect against H. pylori infection, and that the preva-
lence could be highest in children breastfed more than 6
months (18,19). It has been emphasized that horizontal
contagion of infection from nipple to child might occur in
unhygienic mothers. Horizontal contagious can also be ex-
plained as an effect of close contact between a mother and
her child (18). However, in other studies it has been claimed
that breastfeeding has had a major protective effect against
H. pylori infection (14,15). The mechanisms that would pro-
mote an association between H. pylori and breastfeeding are
unclear. In our study, a statistically significant correlation was
not found between breastfeeding and H. pylori positivity. Half
of our children had been breastfed for 6 months (49.1%).
The highest HpSA positivity was reported in children who
had been breastfeeding for 12 months (33.3%). In the study
from Turkey, it was claimed that lack of breastfeeding was
an important risk factor for H. pylori infection (15). On the
other hand, the other population-based study stated that the
prevalence of H. pylori was found to be 8.4% in children
who had never been breastfed (19). This ratio was 5.8% in
our study. The relationship between HpSA positivity and the
breastfeeding duration of the children is presented in Figure
Infected mothers play an important role in H. pylori trans-
mission to their children. However, the education level of
the mothers, the number of siblings, living space, and family
income also strongly affect the living conditions of the family
and their H. pylori positivity. H. pylori infection is more com-
mon in families with the lowest income and education level.
The best way to decrease the prevalence of H. pylori infec-
tion in children is, therefore, to support women in increasing
their education and protecting themselves from H. pylori
infection. We speculated that increasing the education levels
of mothers would improve the hygienic conditions in their
homes. Mothers must be given the opportunity to learn pro-
tective measures for avoiding H. pylori, including improving
their standards of hygiene.
Thanks to Associate Professor Remzi Altunıs ¸ık for supporting statistical
analysis. Thanks to Aysegul Dogan and Pınar Obakan for helping in sample
1. Tindberg, Y., Nyren, O., Blennow, M., et al. (2001): Helicobacter
pylori infection in Swedish school children: lack evidence of child-to-
child transmission outside the family. Gastroenterology , 121, 310-316.
2. Taneike, I., Tamura, Y., Shimizu, T., et al. (2001): Helicobacter pylori
intrafamilial infections: change in source of infection of a child from
father to mother after eradication therapy. Clin. Diagn. Lab. Immunol.,
3. Dominici, P., Bellentani, S., Di Biase, A.R., et al. (1999): Familial clus-
tering of Helicobacter pylori infection: population based study. Br. Med.
J., 319, 537-540.
4. Perez-Perez, G., Rothenbacher, D. and Brenner, H. (2004): Epidemiology
of Helicobacter pylori infection. Helicobacter, 1, 1-6.
5. Czinn, S.J. (2005): Helicobacter pylori infection: detection, investiga-
tion and management. J. Pediatr., 146, 21-26.
6. Rothenbacher, D., Bode, G., Berg, G., et al. (1999): Helicobacter
pylori among preschool children and their parents: evidence of parent-
child transmission. J. Infect. Dis., 179, 398-402.
7. Hauser, B., Wybo, I., Tshibuabua, G., et al. (2006): Multiple-step
polyclonal versus one-step monoclonal enzyme immunoassay in the
detection of Helicobacter pylori antigen in the stools of children. Acta
Paediatr., 95, 297.
8. Konstantopoulos, N., Rüssmann, H., Tasch, C., et al. (2001): Evalua-
tion of the Helicobacter pylori stool antigen test (HpSA) for detection
of Helicobacter pylori infection in children. Am. J. Gastroenterol., 96,
9. De Carvalho Costa Cardinali, L., Rocha, G.A., Rocha, A.M., et al.
(2003): Evaluation of [13C]urea breath test and Helicobacter pylori stool
antigen test for diagnosis of H. pylori infection in children from a
developing country. J. Clin. Microbiol., 41, 3334-3335.
10. Gisbert, J.P. and Pajares, J.M. (2004): Stool antigen test for the diagnosis
of Helicobacter pylori infection: a systematic review. Helicobacter, 9,
11. Chang, M.C., Chang, Y.T., Sun, C.T., et al. (2002): Quantitative correla-
tion of Helicobacter pylori stool antigen (HpSA) test with 13C-urea
breath test (13C-UBT) by the updated Sydney grading system of gastri-
tis. Hepatogastroenterology, 49, 576-579.
12. Wizla-Derambure, N., Michaud, L., Ategbo, S., et al. (2001): Familial
and community environmental risk factors for Helicobacter pylori
infection in children and adolescents. J. Pediatr. Gastroenterol. Nutr.,
13. Goodman, K.J. and Correa, P. (2000): Transmission of Helicobacter
pylori among siblings. Lancet, 355, 358-362.
14. Malaty, H.M., Logan, N.D., Graham, D.Y., et al. (2001): Helicobacter
pylori infection in preschool and school-aged minority children. Effect
of socioeconomic indicators and breast-feeding practices. Clin. Infect.
Dis., 32, 1387-1392.
15. Ertem, D., Harmancı, H. and Pehlivanoglu, E. (2003): Helicobacter
pylori infection in Turkish preschool and school children: role of socio-
economic factors and breastfeeding. Turk. J. Pediatr., 45, 114-122.
16. Ozen, A., Ertem, D. and Pehlivanoglu, E. (2006): Natural history and
symptomatology of Helicobacter pylori in childhood and factors deter-
mining the epidemiology of infection. J. Pediatr. Gastroenterol. Nutr.,
17. Abasiyanik, M.F., Tunc, M. and Salih, B.A. (2004): Enzyme immuno-
assay and immunoblotting analysis of Helicobacter pylori infection in
Turkish asymptomatic subjects. Diagn. Microbiol. Infect. Dis., 50, 173-
18. Kitagawa, M., Natori, M., Katoh, M., et al. (2001): Maternal transmis-
sion of Helicobacter pylori in the perinatal period. J. Obst. Gynaecol.
Res., 27, 225-230.
19. Rothenbacher, D., Bode, G. and Brenner, H. (2002): History of
breastfeeding and Helicobacter pylori infection in pre-school children:
results of a population-based study from Germany. Int. J. Epidemiol.,