Surveillance for Lymphoproliferative disease virus in wild upland game birds in Pennsylvania

Lymphoproliferative disease virus (LPDV) is an exogenous, oncogenic retrovirus recently identified in wild turkeys (Meleagris gallopavo) in the Eastern United States. Historically, LPDV has only been a rare cause of lymphoid... [ view full abstract ]

Lymphoproliferative disease virus (LPDV) is an exogenous, oncogenic retrovirus recently identified in wild turkeys (Meleagris gallopavo) in the Eastern United States. Historically, LPDV has only been a rare cause of lymphoid tumors in domestic turkeys in the Middle East and Europe. However, in 2012, LPDV was identified in a wild turkey from Arkansas with systemic lymphoid tumors. This was the first identification of LPDV in wild turkeys and in North America. Subsequent surveillance showed LPDV infection was widespread and common in wild turkeys throughout the Eastern US, but the occurrence of tumors was rare. Currently, there is little information on the host range of LPDV but experimental data indicates chickens and turkeys are susceptible to infection and domestic ducks and geese are resistant. In wild birds, LPDV has only been reported from wild turkeys. To provide insights into the host range of LPDV, bone marrow samples were collected from hunter-harvested and diagnostic submissions of wild turkeys, ring-necked pheasants (Phasianus colchicus), and ruffed grouse (Bonasa umbellus) from Pennsylvania during 2012-2016. None of the birds included in this surveillance had evidence of tumors or lymphoproliferative disease. Samples were tested for LPDV proviral DNA using PCR. Consistent with previous surveillance results in surrounding Northeastern states, LPDV infection in wild turkeys was common (51/64 positive; 80%) and widespread with positive birds being detected in 27/29 counties tested. In contrast, LPDV was not detected in any ruffed grouse (n=77; 14 counties) or ring-necked pheasant (n=13; 3 counties) samples. LPDV positive wild turkeys were identified in 8/14 counties in which ruffed grouse were sampled and 1/3 counties in which ring-necked pheasants were sampled. These results indicate LPDV prevalence in ruffed grouse and ring-necked pheasants is significantly lower than in wild turkeys and suggest that the natural LPDV host range is relatively restricted.