Avian oncogenesis induced by lymphoproliferative disease virus: A neglected or emerging retroviral pathogen?

- LPDV is responsible for periodic fatal tumorigenic disease in galliform birds.
- First description of LPDV in North America.
- First description of LPDV in wild birds.
- Phylogenetic analysis suggests transcontinental spread between New and Old World.
- LPDV has likely been the clandestine agent in many undiagnosed cases of neoplasia.

Lymphoproliferative disease virus (LPDV) is an exogenous oncogenic retrovirus that induces lymphoid tumors in some galliform species of birds. Historically, outbreaks of LPDV have been reported from Europe and Israel. Although the virus has previously never been detected in North America, herein we describe the widespread distribution, genetic diversity, pathogenesis, and evolution of LPDV in the United States. Characterization of the provirus genome of the index LPDV case from North America demonstrated an 88% nucleotide identity to the Israeli prototype strain. Although phylogenetic analysis indicated that the majority of viruses fell into a single North American lineage, a small subset of viruses from South Carolina were most closely related to the Israeli prototype. These results suggest that LPDV was transferred between continents to initiate outbreaks of disease. However, the direction (New World to Old World or vice versa), mechanism, and time frame of the transcontinental spread currently remain unknown.