HBV Infection Trend in Iranian Disabled Children; Is It really Worrying?

We read with a great interest the article written by Davoodbeglou and colleagues entitled “Evaluation of Hepatitis B Infection Prevalence in Institutionalized Intellectually Disabled Children” which is recently published in your prestigious journal1. The authors concluded that HBV infection is more prevalent among institutionalized disabled children and that we should change our health policies for HBV infection management in this population. They have conducted a valuable study with an important subject in a high risk population for hepatitis. Despite our interest to the findings of Davoodbeglou et al. study there are some challenging points about their work; so we think that some comments may be of benefit. The first, authors have claimed a higher prevalence of HBV infection among vaccinated children in comparison with those with no or undetermined vaccination history. While there are studies in which the efficacy of neonatal HBV immunization has been proven2. How the authors justify this finding?
In addition the authors have not mentioned the sampling method of their study which is the crucial factor of prevalence studies. This may seriously affect the results of study. Also the time period in which the study was conducted has not been determined by the authors. Was it after or before distribution of national vaccination program for hepatitis B? In this regard we should be aware of the maximum age of disabled individuals included in the study.
In conclusion we appreciate the valuable effort of the authors; however we were wondering if we could kindly ask them to interpret better our concerns.