Nonvirulent Infectious Salmon Anemia Virus (ISAV-HPR0) Not Detectable in Eggs or Progeny of Infected Captive Atlantic Salmon Brood

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The brief report « Non-virulent infectious salmon anemia virus (ISAV-HPR0) not 2 detectable in eggs or progeny of infected Atlantic salmon brood” by Polinsky et al. describes screening for infectious salmon anemia virus (ISAV) in eggs and gill clips from a number of family crosses using qPCR where most of the broodfish (both male and female) had tested positive for ISAV HPR0. There were no findings of positive PCRs that could have indicated vertical transmission of this virus variant under the management conditions used.

The report is well written, and the message is easy to grasp. Tables are ok. I have very few comments or suggestions for corrections.

Minor suggestions.

The title should reflect that the study concerns cultured Atlantic salmon. The study does not encompass wild fish and therefore not Atlantic salmon as such.

A short, written sketch of the normal treatment of the eggs could be given in the M&M.

I’m surprised by that for one of the cohorts of the study there were no egg-disinfection protocols implemented – is that common? In most part of the salmon-farming world such protocols are mandatory.

Author Response

Comment 1: The title should reflect that the study concerns cultured Atlantic salmon. The study does not encompass wild fish and therefore not Atlantic salmon as such.

Response 1: "captive" has been added to the title to specifically indicated cultured rather than wild fish.

Comment 2: A short, written sketch of the normal treatment of the eggs could be given in the M&M.

Response 2: "as per standard industry practice" has been added to Ln142 to indicate this description is normal egg treatment processing.

Comment 3: I’m surprised by that for one of the cohorts of the study there were no egg-disinfection protocols implemented – is that common? In most part of the salmon-farming world such protocols are mandatory.

Response 3: Egg-disinfection is typically utilized at this facility and in commercial/or state-run aquaculture facilities in the United States. This was not done in 2018 partly to maximize the chance of detecting ISAV-HPR0 vertical transmission in this study and also as an attempt to potentially boost eye-up rate (we have seen a ~5% eye-up rate reduction by using iodophor). We do not feel that this explanation would enhance the manuscript and therefore no changes have been applied to the text in this regard. 

Reviewer 2 Report

Comments and Suggestions for Authors

With the exception of one minor comment, I have no criticism of this paper. I have deemed it acceptable to publish it in Viruses as is.

Line 54, please check "at least in in some instances"

Author Response

Comment 1: Line 54, please check "at least in in some instances"

Response 1: We have corrected the typographical error. The section now reads " at least in some instances"