Current understanding of lymphoproliferative disease virus in wild turkeys

Lymphoproliferative disease virus (LPDV) has been detected in healthy and moribund wild turkeys (Meleagris gallopavo) throughout the United States and Canada. High LPDV prevalence paired with regional population declines in wild turkeys have generated interest in investigating its potential effects on population health. Progress has been made in elucidating pathogenesis, determining spatiotemporal patterns of infected wild turkeys, and developing diagnostic tests since initial LPDV documentation in the United States in 2009. While infection generally does not lead to outward signs of disease, it can cause widespread tumors in skin and internal organs. We reviewed literature on LPDV in domestic and wild turkeys to consolidate our current understanding of LPDV. Estimated LPDV prevalence among wild turkeys ranges from 26-83% and varies by region, landscape, and season. Surveillance has revealed the largest prevalence in the northeastern and southeastern United States and central Canada, with detections west to Idaho, USA. Detection of LPDV is most frequently in adult female wild turkeys. Whole blood, bone marrow, and tumors are the most sensitive samples for diagnostic testing; however, LPDV has been detected in dried blood spots, plasma, oropharyngeal and cloacal swabs, and numerous tissues via polymerase chain reaction. In experimentally infected domestic turkeys with North American LPDV strains from wild turkeys, LPDV was detected in blood as early as 7 days post-inoculation and transiently for up to 3 months. Further, domestic turkeys can develop clinical disease as early as 35 days post-inoculation. Although LPDV can spread from turkey-to-turkey, the predominant natural route(s) of transmission is unclear. Additional diagnostic tools to distinguish LPDV lesions from other potential causes are in development. Despite the growing body of research, further work is needed to clarify aspects of epidemiology and potential effects of LPDV on wild turkey reproductive fitness, immune health, and behavior to assess potential population-level effects.