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

Experimental infection of domestic turkeys with lymphoproliferative disease virus of North American origin

Lymphoproliferative disease virus (LPDV) was first documented in wild turkeys in North America in 2009. LPDV infection is often subclinical but can manifest as lymphoid proliferation or round cell neoplasia. Despite high prevalence across many sampled areas corresponding to declining populations of wild turkeys, knowledge regarding LPDV pathogenesis, risk factors for disease development, and associated impacts on population dynamics are unknown. To understand transmission, viral shedding, and tissue tropism, we inoculated 21 domestic turkeys via the oral cavity, crop, nasal cavity, subcutis, or coelomic cavity. For 12 weeks, oropharyngeal swabs, cloacal swabs, and whole blood were collected weekly. At 1 week postinoculation, 3 turkeys (3/21; 14%) had detectable LPDV proviral DNA in blood by polymerase chain reaction, and 10 developed DNAemia (50%; 10/20) by 12 weeks. LPDV proviral DNA was intermittently detected in oropharyngeal and cloacal swabs. Splenomegaly was the most consistent gross finding in DNAemic birds (8/11; 73%). Lymphoid hyperplasia in the spleen was the most significant microscopic finding (9/11; 82%). Three turkeys (3/11; 27%) developed round cell neoplasia characterized by sheets of pleomorphic, round to polygonal cells in the adrenal gland, bone marrow, skin, small intestine, and/or spleen. LPDV was detected in the spleen and bone marrow from all turkeys with DNAemia and all neoplasms. Our study establishes that infection and disease with North American LPDV from wild turkeys can be experimentally reproduced in domestic turkeys, laying the groundwork for future investigations into LPDV pathogenesis, development of diagnostic techniques, and understanding the impacts of LPDV on wild turkey populations.

Detection of lymphoproliferative disease virus in Iowa Wild Turkeys (Meleagris gallopavo): Comparison of two sections of the proviral genome

An accurate diagnostic test is an essential aspect of successfully monitoring and managing wildlife diseases. Lymphoproliferative Disease Virus (LPDV) is an avian retrovirus that was first identified in domestic turkeys in Europe and was first reported in a Wild Turkey (Meleagris gallopavo) in the United States in 2009. It has since been found to be widely distributed throughout North America. The majority of studies have utilized bone marrow and PCR primers targeting a 413-nucleotide sequence of the gag gene of the provirus to detect infection. While prior studies have evaluated the viability of other tissues for LPDV detection (whole blood, spleen, liver, cloacal swabs) none to date have studied differences in detection rates when utilizing different genomic regions of the provirus. This study examined the effectiveness of another section of the provirus, a 335-nucleotide sequence starting in the U3 region of the LTR (Long Terminal Repeat) and extending into the Matrix of the gag region (henceforth LTR), for detecting LPDV. Bone marrow samples from hunter-harvested Wild Turkeys (n = 925) were tested for LPDV with the gag gene and a subset (n = 417) including both those testing positive and those where LPDV was not detected was re-tested with LTR. The positive percent agreement (PPA) was 97.1% (68 of 70 gag positive samples tested positive with LTR) while the negative percent agreement (NPA) was only 68.0% (236 of 347 gag negative samples tested negative with LTR). Cohen's Kappa (κ = 0.402, Z = 10.26, p<0.0001) and the McNemar test (OR = 55.5, p<0.0001) indicated weak agreement between the two gene regions. We found that in Iowa Wild Turkeys use of the LTR region identified LPDV in many samples in which we failed to detect LPDV using the gag region and that LTR may be more appropriate for LPDV surveillance and monitoring. However, neither region of the provirus resulted in perfect detection and additional work is necessary to determine if LTR is more reliable in other geographic regions where LPDV occurs.

First Report of Marek's Disease Virus in Commercial Turkeys in Slovenia

Marek's disease (MD), caused by Mardivirus gallidalpha 2 (GaAHV-2), also known as MD virus (MDV), is a lymphoproliferative disease that primarily affects chickens. Recently, MDV has been detected in lymphomatous tumors in turkeys in various countries. Between 2021 and 2023, three cases ranging from no to severe clinical disorders (depression, lameness, and increased mortality) occurred in commercial turkey flocks in Slovenia. In all cases, MDV was detected by PCR in DNA samples extracted from organs developing tumor infiltrations. Sequencing and phylogenetic analysis of the meq gene revealed that the GaAHV-2 detected has molecular features of a very virulent pathotype and genetic similarity with GaAHV-2 detected in chickens in Tunisia. This is the first report of MDV in commercial turkeys in Slovenia.

Lymphoproliferative Disease Virus and Reticuloendotheliosis Virus Detection and Disease in Wild Turkeys (Meleagris gallopavo)

Lymphoproliferative disease virus (LPDV) and reticuloendotheliosis virus (REV) are oncogenic retroviruses that can cause disease in wild and domestic fowl. Lymphoproliferative disease virus infections are common and widespread in Wild Turkeys (Meleagris gallopavo) in the US and east-central Canada, while REV has been detected worldwide in numerous avian host species. We tested tissues (spleen, liver, and/or bone marrow, plus neoplastic tissue, if present) from 172 Wild Turkeys that underwent necropsy from December 2018 through October 2021 for both viruses using PCR. We evaluated demographic, geographic, temporal, and seasonal data by chi-square test of independence and logistic regression for turkeys infected with LPDV and/or REV. At least one of these retroviruses was detected in 80.8% (139/172) of Wild Turkeys from 15 US states, with significantly more turkeys being positive for LPDV (72.1%, 124/172) versus REV (43.6%, 75/172; P<0.001). Both viruses (coinfections) were detected in 34.9% (60/172) of turkeys. Among LPDV-infected turkeys (including coinfections), bone marrow had the highest detection rate (38/58, 65.5%), significantly higher than spleen (30/58, 51.7%) and liver (20/58, 34.5%; P<0.001). In REV-infected turkeys, bone marrow had the highest detection rate (24/58, 41.4%). All three tissues (spleen, liver, bone marrow) concurrently tested positive in most (15/25, 60%) REV-infected turkeys. These results suggest LPDV tissue tropism for bone marrow, whereas REV may have broader tissue tropism. Histopathology consistent with lymphoid proliferation and/or neoplasia characteristic of lymphoproliferative disease was evident in 29/172 (16.9%) turkeys assessed, including two REV-only-infected turkeys. Season was significantly associated with LPDV prevalence (highest in winter); year and season were both significantly associated with REV prevalence (highest in 2020 and winter). These data contribute to optimizing diagnostic strategies that may aid in pathogen monitoring and improve detections to increase our understanding of the potential impacts of these viruses on Wild Turkey populations.

Comparison of Endogenous Alpharetroviruses (ALV-like) across Galliform Species: New Distant Proviruses

The Genus Alpharetrovirus contains viruses pathogenic mainly for chickens, forming the Avian Sarcoma and Leukosis Virus group (ASLV). Cells of most Galliform species, besides chickens, contain genetic elements (endogenous retroviruses, ERVs) that could recombine with other alpharetroviruses or express proteins, complementing defective ASLV, which may successfully replicate and cause disease. However, they are quite unknown, and only ALV-F, from ring-necked pheasants, has been partially published. Upon scrutiny of 53 genomes of different avian species, we found Alpharetrovirus-like sequences only in 12 different Galliformes, including six full-length (7.4-7.6 Kbp) and 27 partial sequences. Phylogenetic studies of the regions studied (LTR, gag, pol, and env) consistently resulted in five almost identical clades containing the same ERVs: Clade I (presently known ASLVs); Clade II (Callipepla spp. ERVs); Clade IIIa (Phasianus colchicus ERVs); Clade IIIb (Alectoris spp. ERVs); and Clade IV (Centrocercus spp. ERVs). The low pol identity scores suggested that each of these Clades may be considered a different species. ORF analysis revealed that putatively encoded proteins would be very similar in length and domains to those of other alpharetroviruses and thus potentially functional. This will undoubtedly contribute to better understanding the biology of defective viruses, especially in wild Galliformes, their evolution, and the danger they may represent for other wild species and the poultry industry.

Molecular Surveillance for Lymphoproliferative Disease Virus and Reticuloendotheliosis Virus in Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) in Texas, USA

Reticuloendotheliosis virus (REV) and lymphoproliferative disease virus (LPDV) are avian retroviruses that can cause neoplastic disease and present with similar pathologies. Lymphoproliferative disease virus has been reported in the Eastern US and states bordering Texas, USA, but has not been previously detected within the state. In a prior study, we detected REV in native Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) and an Eastern Wild Turkey (Meleagris gallopavo silvestris) originating from West Virginia. Given LPDV detection in states bordering Texas and our finding of an REV-positive Eastern Wild Turkey imported from a LPDV endemic region, we sought to determine LPDV prevalence in Texas and continue surveillance for REV. During 2018-20, dried blood spots from 373 individual Rio Grande Wild Turkeys from 20 different counties were tested for the presence of proviral REV or LPDV DNA. In affected counties, approximately 4% of individuals were infected with REV (7/197) or LPDV (10/273) and one bird was coinfected with both viruses. Phylogenetic analysis indicated a close relationship of the LPDV isolates to variants from other Southern and Central states. This study provides molecular evidence of LPDV in Texas, and continued surveillance is necessary to determine the potential effects of the virus on reproductive success, coinfections, and overall health of Wild Turkey populations.

An Investigation of the Cause of Wild Turkey Mortality in Mississippi

Lymphoproliferative disease virus (LPDV) is an exogenous alpharetrovirus that sporadically causes fatal lymphoid neoplasia in affected turkeys. Previous studies of wild turkeys (Meleagridis gallopavo) in the United States have demonstrated geographically widespread LPDV infection and frequent coinfection with avian poxvirus (APV) and reticuloendotheliosis virus (REV). This study was conducted to better understand health risks to Mississippi wild turkeys, including the relative importance of LPDV, APV, and REV in contributing to mortality. Thirteen wild turkeys, which died naturally or were euthanized due to illness, were submitted to Mississippi State University's Poultry Research and Diagnostic Laboratory for postmortem examinations. Birds originated from nine counties across the state over the past 5 yr. Carcasses were submitted as fresh (nonfrozen) or frozen. At autopsy, 9 of 13 turkeys had severe, proliferative cutaneous lesions on the head and neck, with diphtheritic or proliferative oral and esophageal lesions. Samples were collected for molecular diagnostic testing (LPDV and REV PCR), histopathology, and bacterial culture and isolation. External and internal parasites were preserved in formalin for identification. APV (cutaneous and/or diphtheritic forms) was diagnosed in 9 of 13 birds by identification of pathognomonic histologic lesions (including intracytoplasmic inclusion bodies). Interestingly, all birds with APV were also REV PCR positive. Furthermore, eight turkeys were positive for LPDV, and LPDV was commonly associated with coinfections with APV and REV.

PATHOGEN SURVEY AND PREDICTORS OF LYMPHOPROLIFERATIVE DISEASE VIRUS INFECTION IN WILD TURKEYS (MELEAGRIS GALLOPAVO)

Growing populations of Wild Turkeys (Meleagris gallopavo) may result in increased disease transmission among wildlife and spillover to poultry. Lymphoproliferative disease virus (LPDV) is an avian retrovirus that is widespread in Wild Turkeys of eastern North America, and infections may influence mortality and parasite co-infections. We aimed to identify individual and spatial risk factors of LPDV in Maine's Wild Turkeys. We also surveyed for co-infections between LPDV and reticuloendotheliosis virus (REV), Mycoplasma gallisepticum, and Salmonella pullorum to estimate trends in prevalence and examine covariance with LPDV. From 2017 to 2020, we sampled tissues from hunter-harvested (n=72) and live-captured (n=627) Wild Turkeys, in spring and winter, respectively, for molecular detection of LPDV and REV. In a subset of captured individuals (n=235), we estimated seroprevalence of the bacteria M. gallisepticum and S. pullorum using a plate agglutination test. Infection rates for LPDV and REV were 59% and 16% respectively, with a co-infection rate of 10%. Seroprevalence for M. gallisepticum and S. pullorum were 74% and 3.4%, with LPDV co-infection rates of 51% and 2.6%, respectively. Infection with LPDV and seroprevalence of M. gallisepticum and S. pullorum decreased, whereas REV infection increased, between 2018 and 2020. Females (64%), adults (72%), and individuals sampled in spring (76%) had higher risks of LPDV infection than males (47%), juveniles (39%), and individuals sampled in winter (57%). Furthermore, LPDV infection increased with percent forested cover (β=0.014±0.007) and decreased with percent agriculture cover for juveniles (β=-0.061±0.018) sampled in winter. These data enhance our understanding of individual and spatial predictors of LPDV infection in Wild Turkeys and aid in assessing the associated risk to Wild Turkey populations and poultry operations.

Characterization of Avian Pox in a Ruffed Grouse (Bonasa umbellus) from Pennsylvania

A free-ranging, adult male ruffed grouse (Bonasa umbellus) was harvested by a hunter during November 2019 in Forest County, PA. The bird was submitted for necropsy due to a skin mass on its left leg. Upon necropsy, two proliferative skin masses were grossly visible, one on the left leg and one on the cere. An additional mass was present on the oropharyngeal mucosa covering the hard palate. These masses were diagnosed as avian pox based on histopathologic and cytologic findings, including marked epithelial hypertrophy, hyperplasia, vacuolar degeneration with eosinophilic stippling, and intracytoplasmic inclusion bodies. An avipoxvirus was detected using PCR and was identified as fowlpox virus through sequencing of the 4b core gene segment. The avipoxvirus from this case showed genetic similarity to isolates from Eastern wild turkeys (Meleagris gallopavo silvestris).

Two Cases of Marek's Disease in Backyard Turkeys

In two independent submissions, a 3-yr-old, dead Bourbon Red turkey tom from a zoo and a Royal Palm turkey hen from a backyard flock were submitted for necropsy. Both birds had been kept together with chickens. Findings of the necropsy of the first turkey were an enlarged and dark liver with many pale white foci and a few small white nodules, pale and enlarged spleen, prominent thymus, mottled and pale kidneys, and pale and enlarged testes. Findings of the necropsy of the second turkey were a dark and mildly enlarged liver and severely enlarged, firm, and pale kidneys. Histopathology revealed infiltration of most organs of both birds with neoplastic lymphocytes, which were uniform in the first turkey and pleomorphic in the second turkey. Immunohistochemistry with a CD3 marker identified the neoplastic lymphocytes as T cells. Marek's disease virus serotype 1 was detected with PCR in the livers of both birds, whereas PCRs for reticuloendotheliosis virus and lymphoproliferative disease virus were negative. Based on these findings, Marek's disease was diagnosed in both turkeys, which is very rare and were the first definitive cases reported in the United States. It is likely that the chickens were the source of infection.

Lymphoproliferative Disease Virus in Wild Turkeys (Meleagris gallopavo) from Manitoba and Quebec, Canada

This study describes the first recognized clinical case of lymphoproliferative disease virus (LPDV) in Canada and extends the range of LPDV in Canada through its detection in Manitoba and Quebec. We assessed the prevalence of LPDV in eastern wild turkeys (Meleagris gallopavo silvestris) with the use of whole, clotted blood from live birds in Manitoba (n = 65) and tissue samples collected postmortem in Quebec (n = 4). We tested for LPDV proviral DNA through PCR amplification and sequencing of a portion of the gag (p31) gene. Samples were also tested for reticuloendotheliosis virus (REV) by PCR. Twenty-four birds (34.8%) were positive for LPDV, including all diagnostic cases. One bird (1.4%) from Quebec had gross and microscopic lesions consistent with LPDV. Two turkeys (2.9%) were REV positive, one (1.4%) of which was co-infected with LPDV. Phylogenetic analysis of LPDV strains from Quebec and Manitoba grouped with previously sequenced samples from Ontario and publicly available sequences from a North American lineage. This study contributes valuable information toward ongoing surveillance and monitoring of LPDV in North America.

Multicentric Round Cell Neoplasms and Their Viral Associations in Wild Turkeys (Meleagris gallopavo) in the Southeastern United States

Multiple oncogenic viruses, including lymphoproliferative disease virus (LPDV) and reticuloendotheliosis virus (REV), have been detected in wild turkeys (Meleagris gallopavo). The prevalence of infection with these viruses appears to be more common than overt disease; thus, data on the manifestation of associated disease in wild turkeys are scarce. Diagnostic records from wild turkeys submitted to the Southeastern Cooperative Wildlife Disease Study from 1980 to 2017 were reviewed to identify cases of neoplasia. Neoplasia was reported in 59 of 851 (6.9%) wild turkeys submitted. Of the cases of neoplasia tested by polymerase chain reaction, LPDV was detected in 34 of 58 (59%), REV in 10 of 39 (26%), both viruses in 3 of 39 (8%), and no retroviruses detected in 5 of 39 (13%) turkeys. The most common gross lesions observed among turkeys with neoplasms were emaciation (30/40; 75%); nodules in the skin (26/59; 44%), liver (17/59; 29%), or spleen (9/59; 15%); and splenomegaly (14/59; 24%). Microscopically, nodules were composed of pleomorphic round cells with large eccentric nuclei and prominent nucleoli resembling lymphocytes or lymphoblasts (57/59; 97%) except for 2 cases, one of myeloid cell origin and the other with primarily spindloid cells. This study indicates the need to characterize the pathogenesis and potential health threat posed by REV and LPDV to wild turkeys. Experimental infection studies and the development of additional diagnostic tests to confirm the role of retroviruses in lymphoproliferative disease are warranted.

Survey of Reticuloendotheliosis Virus in Wild Turkeys (Meleagris gallopavo) in Texas, USA

Reticuloendotheliosis virus (REV) is an immunosuppressive and sometimes oncogenic avian retrovirus that establishes lifelong infection in a wide range of avian species. REV-infected wild birds roaming near at-risk captive flocks, such as is the case for the highly endangered Attwater's Prairie Chicken (APC; Tympanuchus cupido attwateri), could act as a reservoir for viral transmission. In wild birds, prevalence rates of REV are low and appearance of associated disease is uncommon. During 2016-17, nearly half of all captive adult APC mortality at Fossil Rim Wildlife Center captive breeding facility in Glen Rose, Texas, US was attributed to REV infection. The unusually high REV prevalence rate prompted us to survey for this virus in wild galliforms throughout the region. From 2016-17, 393 blood samples collected from two subspecies of Wild Turkeys (Meleagris gallopavo) were tested for REV proviral DNA through amplification of the viral 3' long terminal repeat and segments of the viral pol gene. In REV-affected counties, 5% (5/98) of native Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) were identified as REV-positive. In addition, we detected REV in one of 62 Eastern Wild Turkeys (Meleagris gallopavo silvestris) that had been imported during conservation efforts. To better determine protective measures, continued surveillance, including collection and genetic analysis of REV-infected samples, is necessary to identify sources of REV outbreaks in captive APC flocks.

Central Nervous System B-cell Lymphoma in a Bald Eagle ( Haliaeetus leucocephalus)

An adult bald eagle ( Haliaeetus leucocephalus) presented for nystagmus and an inability to fly. On physical examination, the eagle was open-mouth breathing and tachycardic at 200 beats per minute, had a wrinkled cere and sunken eyes, and was an estimated 10% dehydrated. Additionally, the eagle was extremely weak, with neurologic abnormalities including bilateral proprioceptive deficits, nystagmus, and no pupillary light reflex in the left eye. Despite aggressive treatment, the eagle continued to decline rapidly and subsequently died. On histologic examination, diffuse and widespread infiltration of neoplastic lymphocytes was present in the brain, optic nerves, and pecten. Immunohistochemical PAX-5 labeling confirmed B-cell lymphoma confined to the eye and nervous system. Test results for select avian retroviruses, Marek's disease, West Nile virus, avian influenza viruses, and Mycoplasma were negative. To our knowledge, this is the first report of B-cell lymphoma in a bald eagle. Although rare, this condition is a differential diagnosis in cases of neurologic or ocular diseases in birds.

Galliformes and Columbiformes

Galliformes and columbifomes are closely associated with humans and some species have been domesticated for well over 5000 years. Both orders remain diverse, ranging from the common domestic poultry species (e.g., chicken, turkey, and squabs) to the more exotic species found in the wild and in zoological collections. While many species have been benefited from human activities and have increased their ranges, others have declined in numbers and some have become threatened (e.g., Trinidad piping-guan and wood quail) or even extinct (e.g., dodo and passenger pigeon). Nondomestic galliformes and columbiformes are susceptible to many of the same diseases that occur in domestic species, yet predisposition may be different. Furthermore, disease prevalence depends on exposure and potential risk factors. Infectious diseases that tend to be more common under intensive commercial production may not pose as great a risk to exotic and free-living species.

Mortality and Disease in Wild Turkeys ( Meleagris gallopavo silvestris) in Ontario, Canada, from 1992 to 2014: A Retrospective Review

Wild turkeys ( Meleagris gallopavo silvestris) were extirpated from Ontario, Canada, in the early 1900s due to unregulated over-hunting and habitat loss. Despite a successful reintroduction program and strong population numbers, information regarding the health of wild turkeys in Ontario is scarce. A 22-yr (1992-2014) retrospective study was performed to evaluate diagnostic data, including the cause(s) and contributors to death, in wild turkeys submitted to the Ontario-Nunavut node of the Canadian Wildlife Health Cooperative (n = 56). Noninfectious diagnostic findings (39/56; 69.6%) were more common than infectious, with emaciation recognized most frequently (n = 19; 33.9%) followed by trauma (n = 11, 19.6%). The majority of deaths due to emaciation occurred in winter and spring (17/18; 94.4%), which is consistent with lack of access to or availability of food resources. Morbidity and mortality due to infectious diseases was diagnosed in 16 (28.6%) wild turkeys. Avian poxvirus was the most common infectious cause of disease (n = 7; 12.5%), followed by bacterial infections (n = 5; 8.9%), the most common of which was Pasteurella multocida . Zinc phosphide toxicosis (n = 7; 12.5%) occurred in two incidents involving multiple birds. This study aims to provide baseline data that can be used for reference and comparison in future wild turkey disease surveillance and population monitoring studies.

A RETROSPECTIVE STUDY OF CAUSES OF SKIN LESIONS IN WILD TURKEYS (MELEAGRIS GALLOPAVO) IN THE EASTERN USA, 1975-2013

Skin lesions of Wild Turkeys ( Meleagris gallopavo ) are a common cause of concern to wildlife biologists and the general public and are a frequent reason for submission to diagnostic laboratories. The purpose of this retrospective study is to evaluate the causes, occurrence, and epidemiologic patterns of skin lesions in Wild Turkeys in the eastern US. Skin lesions were diagnosed in 30% (n=199) of the 660 Wild Turkey samples submitted to the Southeastern Cooperative Wildlife Disease Study diagnostic service from 1975 to 2013. Avian pox was the most frequent cause of skin lesions (66%, n=131), followed by bacterial dermatitis (22%, n=44), ectoparasitism-related dermatitis (3%, n=6), fungal dermatitis (2.5%, n=5), and neoplasia (2.0%, n=4). Although the gross appearance of skin lesions is often insufficient to determine the etiology, the anatomic distribution of lesions and temporal occurrence of certain diseases may offer insights into likely causes. Cases with lesions involving or restricted to the head and neck were much more likely to be caused by avian pox than other etiologies. Similarly, lesions restricted to the feet were more likely to be of bacterial origin. Skin lesions observed in the fall and winter were more likely to be caused by avian pox, whereas bacterial dermatitis was more frequently observed in the spring and summer. This retrospective study provides a summary of the causes of skin lesions in Wild Turkeys and serves as a useful reference to diagnosticians and biologists when evaluating Wild Turkeys with skin lesions.

Molecular Surveillance for Lymphoproliferative Disease Virus in Wild Turkeys (Meleagris gallopavo) from the Eastern United States

Lymphoproliferative disease virus (LPDV) is a poorly understood, oncogenic avian retrovirus of domestic turkeys that has historically been restricted to Europe and Israel. However, a recent study reported LPDV in multiple wild turkey diagnostic cases from throughout the eastern United States of America (USA). To better understand the distribution of LPDV in the eastern USA, we surveyed 1,164 reportedly asymptomatic hunter-harvested wild turkeys from 17 states for the presence of LPDV proviral DNA by PCR. In total, 564/1,164 (47%) turkeys were positive for LPDV. Wild turkeys from each state had a relatively high prevalence of LPDV, although statewide prevalence varied from 26 to 83%. Phylogenetic analysis revealed two major clades of LPDV in the USA, although one was at a low frequency suggesting restricted transmission, as well as significant clustering by state of isolation. To determine the best tissue to target for diagnostic purposes, liver, spleen, and bone marrow were tested from a subset of 15 hunter-harvested wild turkeys and 20 wild turkey diagnostic cases. Overall, bone marrow provided the highest level of detection for both hunter-harvested turkeys and diagnostic cases. The sensitivity of LPDV detection between tissues was not significantly different for diagnostic cases, but was for hunter-harvested birds. These results indicate that LPDV infection is common and widespread in wild turkey populations throughout the eastern USA, even without overt signs of disease.