Glen- yes, that research is very much to the point of what I was asking- thank you for finding that. I was only able to read the abstract (no link I could find to the actual study) , but it does counter the general thought that the virus can only be transmitted from bee to bee, horizontally, or vertically. It suggests the these RNA viruses also have a life span in wax and in air. That seems significant.

I would also add- that my concern was initially only with reusing comb with dead capped larva in it- which is common in many dead outs, and just feels like a potent source of viral infection. In general, like Richard, I would reinstall comb , but only without brood- though this research seems to suggest that any frame is a possible source of infection.

Peter made the point that the origin of the virus if of no interest, and I assume its longevity of the hose is also of no interest,  as it only is of importance when Varroa is involved. 

I of course understand his point. However, my question is related to the  growing prevalence of more toxic strains of DWV- and wondering if ignoring the virus itself was still a wise approach. I don't doubt that eventually the more virulent strains will win out- but isn't it possible that this is hastened by not treating it as a virulent pathogen capable of evolving into even more toxic strains? And if a particular hive, or hives, in one's apiary have a particularly virulent strain, wouldn't it be a wise thing to treat it at a higher level than as just background noise? Or is that just not practical?

I say that in part as i feel like I often see a "wave" of infection move through an apiary. Certainly drift and mite bombs cause some of this- but it also feels to me like how a very bad cold in humans can spread. I would guess that rhinovirus  exists in humans at all times- but its the virulent strains that one gets sick from, and one wants to stay away from and isolate each season. Mites or no mites- keeping the strain alive and promoting it by moving equipment around, seems counter intuitive. 

Therefore, I was wondering if there might be a duration that one could wait to reduce this possibility. Though it sounds like this information is not readily available. 

Thanks for the input.

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