Thank you for your reply Brian.

Another participant in this LISTSERV sent me this paper (thanks!).  Suresh D. Desai, Santosh Kumar, and Robert W. Currie. 2016. “Occurrence, detection, and quantification of economically important viruses in healthy and unhealthy honey bee (Hymenoptera: Apidae) colonies in Canada.” The Canadian Entomologist. 148:22-35.

Here’s the abstract (I don’t have access on-line to the full paper without making a trip to the university library). https://www.cambridge.org/core/journals/canadian-entomologist/article/occurrence-detection-and-quantification-of-economically-important-viruses-in-healthy-and-unhealthy-honey-bee-hymenoptera-apidae-colonies-in-canada/F541AD2772E090F4AF96D74AE74A762C

I take note of the authors’ use of qPCR. In discussing their results they propose that “[q]uantitative data on unhealthy colonies provide important baseline information on the pathogen profile and range of virus concentrations in collapsing colonies that will inform the design of future studies on the impacts of specific viruses” (p.30). Nonetheless, data are not presented that would link qPCR data with thresholds for clinical manifestation of a given viral infection; that was not a purpose of their research.

Several of us in my beekeeping cohort in Newfoundland have already come to the conclusion that the current results of virus testing through the National Bee Diagnostic Centre in Alberta and the Animal Health Laboratory at the University of Guelph are of little practical value for our beekeeping craftwork. Sure, it’s helpful to know that SBV turned up in my colonies; I’ll keep my eyes open for it and it will be variable I’ll consider should I have a problem with a colony in the spring. But otherwise, the test results, which consist of a simple (+) or (-), presence or absence of a virus, are not particularly helpful in terms of other beekeeping practices (e.g., managing traffic in bees, comb and other used beekeeping equipment among apiaries).  Lack of confidence in test results does not help the situation. qPCR values also are of no practical use to us, as I noted previously.

I note the following in the Desai, et al. paper: “Our results suggest that since unhealthy and healthy colonies had similar prevalence for all viruses within Manitoba and to most viruses across Canada, the identification of the mere presence or absence of bee viruses in colonies is not likely to be useful for assessing the impact of viruses on colonies or informing the development of successful management strategies for colonies.”

All grist for the mill…

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