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Updated: May 31, 2026

Preparation of Virus-Enriched Inoculum for Oral Infection of Honey Bees (Apis mellifera)
Published on: August 26, 2020
Lack of evidence for an association between Iridovirus and colony collapse disorder
Rafal Tokarz1, Cadhla Firth, Craig Street
1Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York, United States of America.
Abstract:
Colony collapse disorder (CCD) is characterized by the unexplained losses of large numbers of adult worker bees (Apis mellifera) from apparently healthy colonies. Although infections, toxins, and other stressors have been associated with the onset of CCD, the pathogenesis of this disorder remains obscure. Recently, a proteomics study implicated a double-stranded DNA virus, invertebrate iridescent virus (Family Iridoviridae) along with a microsporidium (Nosema sp.) as the cause of CCD. We tested the validity of this relationship using two independent methods: (i) we surveyed healthy and CCD colonies from the United States and Israel for the presence of members of the Iridovirus genus and (ii) we reanalyzed metagenomics data previously generated from RNA pools of CCD colonies for the presence of Iridovirus-like sequences. Neither analysis revealed any evidence to suggest the presence of an Iridovirus in healthy or CCD colonies.
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