# Third "quasi-species" of DWV isolated from UK and Hawaii



## JWChesnut (Jul 31, 2013)

A paper looks deeper at the variants of DWV. It isolates a distinct (Type C) quasi species from hives in Devon, UK and on Kauai (non-Varroa Hawaii). It estimates the age from branching off the master Type A at 319 years. It notes introgression forming new combinations (Type A-C) in the Devon population.

It notes that non-Varroa transmitted DWV may absorb hyper-virulence from the DWV Type A strain. It speculates that colony losses in treated colonies may result from these new non-Varroa hypervirulent combinations.

http://www.nature.com/ismej/journal/vaop/ncurrent/pdf/ismej2015178a.pdf


----------



## squarepeg (Jul 9, 2010)

sounds like a plausible explanation for why target thresholds are decreasing and why we still have significant losses despite treating for mites. i haven't read the entire paper jwc, do the authors propose any practical measures that make use of this new knowledge?


----------



## JWChesnut (Jul 31, 2013)

The paper is of "pure research" nature. It proposes DWV as a model organism to study recombinant RNA virus. This might lead to further intensive research, leading to practical steps. The paper refers to the Mordecai paper on the non-treated Swindon apiary where Type B DWV is predominant, and notes that if Type B is Varroa dependent, its transmission in the test apiaries of the present study would be reduced, as the Varroa were treated.

I believe the subtext in the paper is that the virulent strain of DWV (Type A) has escaped from its chief vector (Varroa) by recombining with the background Type C. The recombination forms a non-Varroa transmitted but highly lethal variant. The paper implies that this recombination is an "emerging" disease -- much like epidemic outbreaks of influenza, and such.

The paper concluding paragraph reads:

As well as being of significance to globally
important honey bee health, the ability to study
highly heterogeneous virus genomes is of wider
importance. Cross-species virus transmission and
emergence of new epidemic diseases such as severe
acute respiratory syndrome, Ebola and influenza are
major threats to public health (Parrish et al., 2008).
Exploring the extent of viral diversity in RNA
quasispecies, of which DWV may be a suitable
model, may offer insight into the mechanisms by
which viruses are able to transmit between different
hosts as well as how viruses are able to develop
resistance to antiviral therapies (Domingo et al.,
2012). Further study of the DWV quasispecies may
help to explain how DWV is able to exist as multiple
variants in many hosts, and may elucidate mechanisms
by which it establishes a persistent infection
among several hosts but only proves pathogenic
in some.​


----------



## squarepeg (Jul 9, 2010)

many thanks for sharing the paper jwc. it's scary stuff as to how the viruses (and the virulence associated with them) can change. are you hearing anything through the grapevine about the ongoing work with dwv type b?


----------



## JWChesnut (Jul 31, 2013)

The present paper details a streamlined analysis pipeline for the various DWV variants. This method section will speed up the detection of Type B, and will catalyze future research.

The paper opens the rabbit hole to an Alice-in-Wonderland world where beeks will be frantically breeding Varroa in a last-ditch effort to inoculate the bees with "Type B" in the face of a world wide epidemic of unstoppable non-Varroa Type C. The maligned "mite-bombs" will be auctioned to frantic bidders for thousands of doubloons by those seeking the magic elixirs of Varroa infection.


----------



## squarepeg (Jul 9, 2010)

awesome. care to purchase any futures for my 'mite bombs'?


----------

