Mordecai, et al. published "Superinfection exclusion and the long-term survival of honey bees in Varroa-infested colonies" in 2015. This paper claimed to have isolated a non-virulent strain of DWV, "Type B" characteristic of a non-treatment apiary in England. The non-virulent strain "vaccinated" bees against the virulent versions of the virus.
Randy Oliver, in coordination with Dr. Stephen Martin, organized a citizen science effort to collect viral samples across the US in an effort to detect a similar phenomenon in this country.
I received my apiary results in the morning mail. I know Square Peg participated in this effort, will he also share his per apiary result? His relatively resilient TF apiary is on the opposite end of the spectrum than mine which is a "death trap" for colonies.
Type A = 27.10%, Type B = 72.90%, Type C = NegativeTotal infection = 2.05 x 10^6
About 3/4 dominance of "Type B" in my TF yard. DWV viral loading was on the low end of "moderate" in the researcher's scaling.
Alongside establishing the average total DWV infection in your apiaries, the percentage of each variant has also been calculated. Based on current scientific evidence we understand that colonies with high loads of DWV type A are at a greater risk of dying. The type B variant may be providing some level of ‘protection’ to colonies, although it has been evidenced to be lethal when injected into caged adult bees in laboratory conditions. Type C is rare and is suspected to be lethal, as we found this present in colonies which died unexpectedly during the winter (Please read the suggested papers for more information).
Total infection refers to the average total amount of deformed wing virus detected in the apiary.
High viral loads are those above 1 x 10^10,
Medium loads are in the range of 1 x 10^6 – 1 x 10^10
Low loads are less than 1 x 10^6.
Samples which were extremely low in DWV fell outside the quantifiable; these results are marked as BL .