Reviewer's report
 Helicobacter pylori (H pylori) infection in South-East Europe: the changing prevalence during a Title:
ten-year period and its antigenic profile.
Authors:
Periklis Apostolopoulos (periklisapo@yahoo.com )
Irene Vafiadis (i.vafiadis@grmedia.gr )
Michael Tzivras (pola@med.uoa.gr )
Dimitrios Kourtessas (akorba@med.uoa.gr )
Nicolaos Katsilambros (laennec@techlink.gr )
Athanasios Archimandritis (aarchim@hotmail.com )
 1  27 Dec 2001 Version: Date:
 Dr Angel Lanas Reviewer:
 A paper of limited interest Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
COMMENTS 
The authors of this article evaluate the changes of H. pylori prevalence in 
Greece during a ten-year period. They also evaluate the antigenic profile of 
this infection regarding CagA and VacA status. They found a significant 
decrease of H. pylori infection in Greece between 1987 and 1997. Data support the birth cohort phenomenon for the infection. They also found a high prevalence of type I H. pylori strains in Greece. 
The results of this study agree with previous studies that had already 
reported a similar outcome. It is of interest to note that the study has been carried out in a Mediterranean country where the prevalence of H. 
pylori infection is high. 
COMPULSORY REVISIONS 
1. Patients were obtained from a Gastroenterology clinic rather than from a 
general population sample. Patients suffering from some digestive diseases may have a higher prevalence of H. pylori infection than that found in the general population. The authors should address this issue and describe the 
type of populations analysed. Although they had used 2 different populations 
in 1997 and found no differences between them , there is no subgroup of patients for those older than 65 in the BD-patients group. It would be also of interest to have a similar group (BD ) in 1987. 
2. In order to better define the antigenic profile of H. pylori infection 
and the evolution of this profile with time, it would be important to 
evaluate both CagA and VacA in serum samples obtained in 1987. 
3. This study does not evaluate and does not compare samples from a 
Mediterranean country with those obtained in Scandinavian or other western 
countries. Therefore, the last part of the last paragraph (aim of the study) 
in the background section should be modified. 
4. More information should be provided regarding the statistical methods 
used. Software and type of tests used in the different types of data and 
questions evaluated. They also should address the reason/s for choosing the sample size used in the study. 
5. Spelling errors have been detected in the core text and references. 
Competing interests:
None declared.
Reviewer's report
 Helicobacter pylori (H pylori) infection in South-East Europe: the changing prevalence during a Title:
ten-year period and its antigenic profile.
Authors:
Periklis Apostolopoulos (periklisapo@yahoo.com )
Irene Vafiadis (i.vafiadis@grmedia.gr )
Michael Tzivras (pola@med.uoa.gr )
Dimitrios Kourtessas (akorba@med.uoa.gr )
Nicolaos Katsilambros (laennec@techlink.gr )
Athanasios Archimandritis (aarchim@hotmail.com )
 1  27 Dec 2001 Version: Date:
 Dr Angel Lanas Reviewer:
 A paper of limited interest Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
COMMENTS 
The authors of this article evaluate the changes of H. pylori prevalence in 
Greece during a ten-year period. They also evaluate the antigenic profile of 
this infection regarding CagA and VacA status. They found a significant 
decrease of H. pylori infection in Greece between 1987 and 1997. Data support the birth cohort phenomenon for the infection. They also found a high prevalence of type I H. pylori strains in Greece. 
The results of this study agree with previous studies that had already 
reported a similar outcome. It is of interest to note that the study has been carried out in a Mediterranean country where the prevalence of H. 
pylori infection is high. 
COMPULSORY REVISIONS 
1. Patients were obtained from a Gastroenterology clinic rather than from a 
general population sample. Patients suffering from some digestive diseases may have a higher prevalence of H. pylori infection than that found in the general population. The authors should address this issue and describe the 
type of populations analysed. Although they had used 2 different populations 
in 1997 and found no differences between them , there is no subgroup of patients for those older than 65 in the BD-patients group. It would be also of interest to have a similar group (BD ) in 1987. 
2. In order to better define the antigenic profile of H. pylori infection 
and the evolution of this profile with time, it would be important to 
evaluate both CagA and VacA in serum samples obtained in 1987. 
3. This study does not evaluate and does not compare samples from a 
Mediterranean country with those obtained in Scandinavian or other western 
countries. Therefore, the last part of the last paragraph (aim of the study) 
in the background section should be modified. 
4. More information should be provided regarding the statistical methods 
used. Software and type of tests used in the different types of data and 
questions evaluated. They also should address the reason/s for choosing the sample size used in the study. 
5. Spelling errors have been detected in the core text and references. 
Competing interests:
None declared.
Please review this paper.
user
Reviewer's report
 Helicobacter pylori (H pylori) infection in South-East Europe: the changing prevalence during a Title:
ten-year period and its antigenic profile.
Authors:
Periklis Apostolopoulos (periklisapo@yahoo.com )
Irene Vafiadis (i.vafiadis@grmedia.gr )
Michael Tzivras (pola@med.uoa.gr )
Dimitrios Kourtessas (akorba@med.uoa.gr )
Nicolaos Katsilambros (laennec@techlink.gr )
Athanasios Archimandritis (aarchim@hotmail.com )
 1  27 Dec 2001 Version: Date:
 Dr Angel Lanas Reviewer:
 A paper of limited interest Level of interest:
 Unable to decide on acceptance or rejection until the authors have responded Advice on publication:
to the compulsory revisions
COMMENTS 
The authors of this article evaluate the changes of H. pylori prevalence in 
Greece during a ten-year period. They also evaluate the antigenic profile of 
this infection regarding CagA and VacA status. They found a significant 
decrease of H. pylori infection in Greece between 1987 and 1997. Data support the birth cohort phenomenon for the infection. They also found a high prevalence of type I H. pylori strains in Greece. 
The results of this study agree with previous studies that had already 
reported a similar outcome. It is of interest to note that the study has been carried out in a Mediterranean country where the prevalence of H. 
pylori infection is high. 
COMPULSORY REVISIONS 
1. Patients were obtained from a Gastroenterology clinic rather than from a 
general population sample. Patients suffering from some digestive diseases may have a higher prevalence of H. pylori infection than that found in the general population. The authors should address this issue and describe the 
type of populations analysed. Although they had used 2 different populations 
in 1997 and found no differences between them , there is no subgroup of patients for those older than 65 in the BD-patients group. It would be also of interest to have a similar group (BD ) in 1987. 
2. In order to better define the antigenic profile of H. pylori infection 
and the evolution of this profile with time, it would be important to 
evaluate both CagA and VacA in serum samples obtained in 1987. 
3. This study does not evaluate and does not compare samples from a 
Mediterranean country with those obtained in Scandinavian or other western 
countries. Therefore, the last part of the last paragraph (aim of the study) 
in the background section should be modified. 
4. More information should be provided regarding the statistical methods 
used. Software and type of tests used in the different types of data and 
questions evaluated. They also should address the reason/s for choosing the sample size used in the study. 
5. Spelling errors have been detected in the core text and references. 
Competing interests:
None declared.
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