Review for 10.1186/s12876-018-0767-1 (2018)

Reviewer ’s report  
 
Title:  Characterization of the hepatitis B virus DNA detected in urine of chronic hepatitis B 
patients  
 
Version: 0 Date: 21 Jan 2018 
 
Reviewer:  Eike Steinmann  
 
Reviewer’s report:  
 
In this study Jain et al. investigated the nature of the DNA detected in urine from patients with 
chronic HBV infection to assess the potential infectivity and to correlate HBV DNA detection in 
urine wit h clinical parameters. Urine from 60 HBV patients were analysed for HBV DNA by 
PCR analysis of six regions of the HBV genome. The results show that only one patient 
contained HBV DNA detected by all six regions, but had evidence of blood in the urine. All 
other patients showed partial detection of the six genomic regions from the HBV genome. The 
authors conclude that urine from chronic HBV patients with healthy kidney function should not 
contain full -length HBV DNA and therefore should not be infectious.  
 
The present study addresses an important topic in the prevention of HBV infections and suggests 
that the risk for HBV infection by urine is low. Previous studies have detected HBV DNA in the 
urine, however, only short PCR protocols were used. This study her e closes the gap of 
knowledge in this regard. The experiments are well conducted and the conclusions are drawn in 
the data. I have only minor comments to improve the study:  
 
- For tears, it has been shown that HBV DNA is present and infectious in humanized  mice. 
This study as another example of body fluid transmission can be discussed (Komatsu et 
al. JID 2012).  
 
- The high and low viral loads could be indicated in the table.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please s pecify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
Are you able to assess any statistics in the manuscript  or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
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financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
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below. If your reply is yes to any, please give details below.  
 
'I declare that I have no competing interests'  
 
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