Helicobacter pylori (H. pylori) is a spiral, gram negative bacterium and its role in gastritis, peptic ulcer, gastric carcinoma has been defined. Seroepidemiologic studies have indicated that the infection with this organism is very common throughout the world. Social and economic development decreases the prevalence both within and between countries. In developing countries a high prevalence and early colonization of H. pylori in childhood was described, in contrast to developed ones [1] [2] .

H. pylori infection is diagnosed by invasive and non-invasivemethods. The invasive method involves endo- scopy, followed by other tests, such as rapid urease, histo-pathology, culturing and Polymerase Chain Reaction (PCR). In previous years concern has been raised on the validation of non-invasive tests for assessing. Non- invasive methods include the urea breath test, serologic testsand detecting bacterial antigens in feces. In children, stool antigen test and urea-breath test demonstrated satisfactory sensitivity and specificity for the diagnosis [3] .

In Turkey, results of some seroepidemiological studies of both healthy and symptomatic children, from dif- ferent regions have been reported. Data obtained with non-invasive prodecures based on detecting the bacteria are still limited. Tekirdağ is a province of Turkey, located in the North-West of Turkey, in Thrace Region. No data representing this region, have since been reported. In this study we aimed to obtain the first results of this region with investigating the prevalence of H. pylori infection by using H. pylori stool antigen test in sympto- matic children.

The study was carried out, for a two year period from January 01, 2010 to December 31, 2011. The study population consisted of children between the ages of 6 months to 15 years, who attented to the Clinics of Paediatrics of Tekirdağ State Hospital. The complaints of the children were anemia, gastroenteritis, abdominal pain, nausea and vomiting. Patients were excluded if they had undergone previous treatment for H. pylori, and if they had taken any antibiotics or proton-pump inhibitors in the 4 weeks prior to the study.

After the physical examination stool samples of the children were collected. The stool samples were tested for the presence of H. pylori antigen with ELISA method (DIA.PRO, Diagnostic Bioprobes, Italy) according to the recommendations of the manufacturer.

Evaluating the results, the subjects were divided into three groups based on their ages: Group A (6 months - 5 years), Group B (6 - 10 years) and Group C (11 - 15 years).

All statistical evaluations were performed using the Statistical Package for the Social Sciences (SPSS) for Windows (version 18.0). Descriptive statistics were calculated (frequency, mean and standard deviation) after performing data control. Chi-Square (χ²) test were used to compare for categorical variables. All statistical analyses were performed with a 95% confidence interval (CI) and evaluated that two-ways.

A total of 1441 children, 689 (47.8%) boys and 752 (52.2%) girls, a range age of 6 months to 15 years were studied. Of the stool samples obtained from 1441 children 96 (6.6%) were positive for H. pylori antigen.

The median age of children with H. pylori positive samples was 6.6 ± 4.1. Distribution due to genders was 47.9% girls and 52.1% boys. In H. pylori positive patient group, no difference due to gender was obtained (x² = 0.17, p = 0.68) (see Table 1).

H. pylori stool antigen positivity was, decreasing with age, as 8.9%, 5.8%, 5.2% in Groups A, B and C, respectively (x² = 9.3, p = 0.01) (see Table 2).

During the last decade, investigators focused on the role of H. pylori, the cause of gastritis and peptic ulcer dis- ease, in the development of other digestive diseases and several extra-intestinal pathologies (iron deficiency anemia (IDA), growth retardation, idiopathic thrombocytopenic purpura (ITP), asthma andallergic disorders) [4] [5] .

H. pylori, shows worldwide distribution, predominantly in countries or regions with poor socioeconomic con- ditions. All studies to date have shown an inverse relationship between H. pylori infection and socioeconomic status. Person-to-person spread is widely considered to be the most prevalent means of transmission. H. pylori

(x² = 0.17, p = 0.68).

(x² = 9.3, p = 0.01).

infection is most likely to occur in populations in which fecal-oral disease transmission is common [4] [6] . Early acquisition of H. pylori occurs generally in children less than five years ofage and the agent does not lead to clinically apparent disease. In some developing countries, most of the population is reported to be infected by age ten years and infection is universal by midlife. Similarly, our results showed that, majority of the H. pylori antigen positive children were exposed to the agent in the first 10 years of life [2] [6] .

Seroepidemiological studies have shown that a large proportion of healthy people have antibodies against H. pylori and infection rate increases with advancing age [6] . Some serological studies conducted in asymptomatic Turkish children showed the overall seropositivity rates, ranging between 30.9% - 78.5% [7] - [16] . The results of a study in asymptomatic people in Turkish population indicated that, more than 30% of the subjects acquired infection before teenage and about 70% of adults had antibodies against H. pylori [11] . In a study conducted in the northwest region of Turkey, overall seropositivity was found as 23.9% increasing with age, similar in males and females and inversely related to economic status in asymptomatic children [17] . Data on H. pylori seropre- valence in Turkish children mainly depends on studies carried out in the middle and western regions of Turkey [8] - [10] . But, still there is limited data on seroepidemiology of H. pylori infection among children living in the urban areas of eastern Turkey [15] . In our study, the children had some complaints concerning the disease and we focused on the presence of bacteria. Our results—representing an example of a western region with a developed socio-economic status—showed that, the bacteria presence was decreasing with age that correlates with the results of seroepidemiological studies performed in our country. Also no relationship was observed in H. pylori acquisition due to genders, showing similarly to the results of other studies.

Several invasive and non-invasive tests are available to diagnose H. pylori infection. An ideal test for H. pylori is noninvasive or minimally invasive, highly accurate, inexpensive, and readily available and enables dif- ferentiation between active or past infection with the organism. In addition, such a test must enableto discri- minate the presence of H. pylori infection and H. pylori-associated disease. As such an ideal test do not cur- rently exist, the advantages and drawbacks of tests that are available require critical evaluation and must be as- sessed for suitability for use in children [13] [18] .

Testing of H. pylori antigens in stools has shown promising results in adults for the non-invasive diagnosis of gastric infection [19] and appears to be accurate for use in monitoring the success of eradication therapy. However, patients may be reluctant to collect stool specimens. In addition, refrigerated stools are more difficult to test. For children, H. pylori stool antigen test is a suitable test with many of the above characteristics. Studies about the performance of test has revealed the sensitivity 96% - 98% and specificity 80% - 100% [20] [21] .

Diagnostic methods based on the isolation of bacteria is still the gold standard, but the requirement of an invasive procedure restricts its usage in the pediatric age group. For this reason this study was planned to detect the presence of the bacteria with the stool antigen test. The correlations of our results with results of some serological studies conducted in different regions of Turkey has shown this test to be reliable in children. In pediatric population, additional studies in evaluating the accuracy of stool antigen testing for both initial diag- nosis and posttreatment follow-up are required before specific recommendations can be considered [22] .

In conclusion, the data of this study which is based on 1441 children-aged between 6 months to 15 years, who are applied to the hospital in a period of two years, are important, but actually the results of this hospital based study do not represent the community. Our results showing the higher antigen positivity in the first group, indicate the exposure to the agent in the early years of childhood. Lack of hygiene during the baby feeding is very important. In Turkey, there are some traditional behaviors which may lead the acquisition of the agent in early childhood, as sucking the teat before giving it to the baby and sharing the spoons, forks and cups. Such behaviors are common in general population, but more often in uneducated families. So physicians in maternal and child health centers need to give education about the usage of teat and the feeding bottles, as well as the importance of hygiene, hand washing to the patients and education need to be provided in general. So with these data, the importance of preventive measures for the development of H. pylori infection in children, especially in developing countries and societies with poor socioeconomic conditions is emphasized.