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Geographic distribution of wild turkey samples from 17 states by county that tested positive (red) or negative (gray) for LPDV proviral DNA.
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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 o...
Citations
... Because of increased opportunities for pathogen transmission among wild and domestic turkeys and other wild birds, it is important to assess pathogen prevalence in Wild Turkey populations. Two oncogenic avian retroviruses, lymphoproliferative disease virus (LPDV) and reticuloendotheliosis virus (REV), have varied virulence with subclinical to fatal outcomes (Allison et al. 2014; Thomas et al. 2015). Detections of LPDV are widespread in Wild Turkeys, including in Ontario, Manitoba, and Quebec, Canada; the eastern US; and historically in domestic turkeys in Israel and England (Ianconescu et al. 1972;Biggs et al. 1978;Thomas et al. 2015;Alger et al. 2017;MacDonald et al. 2019aMacDonald et al. , 2019bCox et al. 2022;Shea et al. 2022). ...
... Two oncogenic avian retroviruses, lymphoproliferative disease virus (LPDV) and reticuloendotheliosis virus (REV), have varied virulence with subclinical to fatal outcomes (Allison et al. 2014; Thomas et al. 2015). Detections of LPDV are widespread in Wild Turkeys, including in Ontario, Manitoba, and Quebec, Canada; the eastern US; and historically in domestic turkeys in Israel and England (Ianconescu et al. 1972;Biggs et al. 1978;Thomas et al. 2015;Alger et al. 2017;MacDonald et al. 2019aMacDonald et al. , 2019bCox et al. 2022;Shea et al. 2022). Lymphoproliferative disease virus infection may lead to immunosuppression and cachexia concurrent with lymphoid neoplasia, which may predispose birds to severe secondary infections (Niedringhaus et al. 2019) and has been associated with mortality in Wild Turkeys (Allison et al. 2014). ...
... Similar to LPDV, REV can cause lymphoproliferative disease (LPD), with similar clinicopathologic manifestations (Ley et al. 1989;Niedringhaus et al. 2019). Reticuloendotheliosis virus is globally distributed, with associated fatal disease documented in wild turkeys in North Carolina and Georgia, US, and detections in Texas, US, and Brazil, and in other avian species in Brazil and China (Ley et al. 1989;Hayes et al. 1992; Thomas et al. 2015;Stewart et al. 2019;Caleiro et al. 2020;Liu et al. 2020;Shi et al. 2021). Thus far, comparisons of LPDV and REV detection in Wild Turkeys across broader regions of North America are lacking but are necessitated by unknown population health implications of these viruses. ...
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.
... Thus, it will be of interest to determine if the loss of tetherin in wild and domestic birds, such as turkeys and Mikado pheasants, led to higher transmission rates and/or increased susceptibility of these species to various enveloped viruses. Recently, epidemiological monitoring of lymphoproliferative disease virus (LPDV), a retrovirus infecting various fowl species, revealed a rapid spread of this virus in North American wild turkey populations (48)(49)(50). It remains to be determined if the loss of tetherin in turkeys contributed to the extensive dissemination of LPDV in this species. ...
The restriction factor tetherin (bone marrow stromal cell antigen 2) is an interferon-inducible protein preventing the release of newly formed viral particles from infected cells. Tetherin displays antiviral activity against a broad range of enveloped viruses, including retroviruses. While tetherin orthologs have been identified in several mammalian species, little is known about its expression and activity in non-mammalian vertebrates, including birds. We have previously described antiviral activity of chicken ( Gallus gallus ) tetherin against the prototypical avian retrovirus avian sarcoma and leukosis virus (ASLV). Here, we report the loss of functional tetherin orthologs in several galliform birds, including turkey ( Meleagris gallopavo ) and Mikado pheasant ( Syrmaticus mikado ). In both species, the tetherin coding sequence acquired inactivating mutations, including an in-frame stop codon and frameshifting deletions. Similar to the chicken tetherin ortholog, reconstituted turkey and Mikado pheasant tetherins restricted ASLV and HIV-1 indicating antiviral activity of the ancestor protein. Previous work revealed the presence of the TMCC(aT ) gene in close proximity to tetherin, encoding a protein with tetherin-like structure in multiple vertebrates. Intriguingly, ectopic overexpression of chicken and turkey TMCC(aT) proteins in human cells decreased total HIV-1 yield. In contrast to tetherin, however, TMCC(aT) did not specifically restrict virion release, suggesting distinct antiviral mechanisms. In line with this, IFNα stimulation did not reduce the release of ASLV particles from infected turkey cells. Overall, our data describe the loss of functional tetherin genes in several galliform species and identify an antiviral activity of the related TMCC(aT) protein that is mechanistically different from that of tetherin.
IMPORTANCE
Birds represent important hosts for numerous viruses, including zoonotic viruses and pathogens with the potential to cause major economic losses to the poultry industry. Viral replication and transmission can be inhibited or blocked by the action of antiviral restriction factors (RFs) encoded by the host. One well-characterized RF is tetherin, a protein that directly blocks the release of newly formed viral particles from infected cells. Here, we describe the evolutionary loss of a functional tetherin gene in two galliform birds, turkey ( Meleagris gallopavo ) and Mikado pheasant ( Syrmaticus mikado ). Moreover, we demonstrate that the structurally related protein TMCC(aT) exerts antiviral activity in several birds, albeit by a mechanism different from that of tetherin. The evolutionary scenario described here represents the first documented loss-of-tetherin cases in vertebrates.
... However, retrovirus infections are associated with decreased reproductive success, hatchability, and sexual maturation in domestic poultry (Payne 1998;Wei et al. 2012). First identified in the UK in 1972, LPDV has been credited with neoplastic disease outbreaks in Europe and Israel Ianconescu et al. 1983 Thomas et al. 2015;Alger et al. 2017). In a 2016-17 survey, we identified five REVpositive Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) and one REV-positive Eastern Wild Turkey (Meleagris gallopavo silvestris) imported from West Virginia (Stewart et al. 2019). ...
... A discrete gamma distribution was used to model evolutionary rate differences among sites (5 categories [þG, parameter¼0.4955]). The initial analysis involved 195 nucleotide sequences previously published from the US and Israel (Allison et al. 2014; Thomas et al. 2015). Redundant sequences were removed from the dataset and the remaining sequences were re-analyzed. ...
... Our finding that LPDV is present in Texas Wild Turkeys supports previous studies indicating that LPDV is widespread across the Eastern and Central US and that Central states have lower prevalence than the Northeastern, Mid-Atlantic, and Southeastern states (Thomas et al. 2015;Alger et al. 2017). Wild Turkey susceptibility to LPDV may vary by subspecies . ...
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 United States 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.
... In 2009, LPDV was identified in Wild Turkeys in the US, revealing an expanded geographic range for the virus (Allison et al. 2014). Subsequent surveys of apparently healthy Wild Turkeys reported high prevalence (26-83% by state) in the eastern US (Thomas et al. 2015), as well as among provinces in Canada (31-65%; MacDonald et al. 2019a, b). Wild Turkeys can show nonspecific clinical signs suggestive of LPDV infection including lethargy and ataxia, and lesions such as lymphoid proliferation have been reported in 15-25% of LPDV-infected Wild Turkeys submitted to diagnostic laboratories (Allison et al. 2014;MacDonald et al. 2019a). ...
... We extracted bone marrow (postmortem sample type with highest LPDV detection probability; Thomas et al. 2015) from tarsometatarsus bones using flame-sterilized loppers and tweezers sterilized with a Germinator 500 Bead Sterilizer (Cell Point Scientific, Gaithersburg, Maryland, USA). When whole blood samples contained a sufficient volume (n¼256), we centrifuged the EDTA blood tube for 15 min at 775 3 G to isolate the buffy coat (antemortem sample type with highest LPDV detection probability; Alger et al. 2015). ...
... Our estimated LPDV prevalence in Maine's Wild Turkeys is similar to that in New York State, US (55%; Alger et al. 2017) and Ontario, Canada (65%; MacDonald et al. 2019b), but higher than other areas, including South Carolina, US (45%; Allison et al. 2014) and Manitoba, Canada (31%;MacDonald et al. 2019a). These data are in line with Thomas et al. (2015), who found that the northeastern region of North America experiences higher LPDV transmission and prevalence compared with southern and western regions. Increased LPDV transmission at the species' northern range limit could be driven by increased Wild Turkey interactions due to limited nutrient sources during winter months. ...
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.
... Viral-induced neoplasms are not uncommon in domestic poultry, including turkeys. [1][2][3][4] Clinical signs are nonspecific but can include anorexia and lethargy, as was observed in this case. 1,4,5 Microscopically, neoplastic proliferation of lymphoid cells often disrupts and infiltrates the normal architecture in multiple organs. ...
... Spontaneous, systemic round cell tumors occur in older turkeys, but are not a common cause of death. 3 If an operation reports an increased number of turkey deaths, further diagnostic procedures are warranted to rule out a viral agent. Cases of viral-induced neoplasia are rarely reported in backyard poultry, but they may be underdiagnosed because full workups, including retroviral testing, are not always pursued. ...
In collaboration with the American College of Veterinary Pathologists
... In 2009, LPDV proviral DNA was first identified in a wild turkey in the United States, and subsequent surveys revealed a high prevalence (26-83% by state) and broad distribution across the eastern United States (Allison et al. 2014, Thomas et al. 2015, Alger et al. 2017), and Canada (MacDonald et al. 2019a. Although surveillance of hunter-harvested wild turkeys suggested 100% of LPDV-infected turkeys may be outwardly asymptomatic (Thomas et al. 2015), other studies have reported neoplastic lesions in~15% of clinically-ill birds infected with LPDV (Allison et al. 2014). ...
... In 2009, LPDV proviral DNA was first identified in a wild turkey in the United States, and subsequent surveys revealed a high prevalence (26-83% by state) and broad distribution across the eastern United States (Allison et al. 2014, Thomas et al. 2015, Alger et al. 2017), and Canada (MacDonald et al. 2019a. Although surveillance of hunter-harvested wild turkeys suggested 100% of LPDV-infected turkeys may be outwardly asymptomatic (Thomas et al. 2015), other studies have reported neoplastic lesions in~15% of clinically-ill birds infected with LPDV (Allison et al. 2014). However, co-infection of LPDV with other pathogens was also reported (Allison et al. 2014, MacDonald et al. 2019a, raising concerns that LPDV infection may increase susceptibility to other pathogens and induce subsequent disease symptoms. ...
... Current sampling for LPDV diagnostics relies on sampling of blood from live-captured turkeys (Alger et al. 2015), or collection of tissue from dead turkeys (Thomas et al. 2015). The blood's separated buffy coat layer (white blood cells) is the standard sample type for antemortem detection of LPDV in a genetic-based assay (Alger et al. 2015), whereas bone marrow is typically used for postmortem detection (Thomas et al. 2015). ...
The monitoring of infectious diseases in wildlife is crucial for assessing animal health, pathogen range expansion, and the risk of spillover to naive species, but may be resource and labor intensive. Lymphoproliferative disease virus (LPDV) is an avian oncogenic retrovirus that was first identified in wild turkeys ( Meleagris gallopavo ) in 2009, though it historically caused mortality in domestic turkeys in Europe and Israel. Subsequent surveys detected a high prevalence and broad distribution throughout the eastern United States, warranting further research on LPDV in wild turkey populations. Current LPDV diagnostics require the collection of tissues, such as bone marrow from dead birds or blood during live capture. In our study, we assessed the sensitivity (true positive) and specificity (true negative) of cloacal swab samples as an alternative LPDV detection method. We compared results from cloacal swab samples with both postmortem detection from bone marrow and antemortem detection from blood, using a multi‐tube PCR approach with 3 replicates. Swab samples collected from live‐captured turkeys had a greater sensitivity (88%) than swabs collected from hunter‐harvested turkeys (31%), whereas specificity was similar for both collection approaches (live‐capture swabs = 75%, n = 85; hunter‐harvest swabs = 80%, n = 54). In live‐captured turkeys, the estimated LPDV prevalence using cloacal swab samples (73%) was not significantly different from the true prevalence determined using coupled blood samples (76%). However, in hunter‐harvested turkeys, the estimated prevalence using cloacal swab samples (28%) was different from the true prevalence estimated using coupled bone marrow samples (72%). In summary, cloacal swab samples can be used to reliably detect LPDV infection in live‐captured wild turkeys but should not be used for LPDV detection in hunter‐harvested wild turkeys.
... To further investigate LPDV, multiple active surveillance projects were initiated throughout eastern North America (Allison et al. 2014, Alger et al. 2017. The results were consistent among studies, which indicated a high prevalence of LPDV infection among wild turkeys in North America, even in birds that were in apparent good health (Thomas et al. 2015, Alger et al. 2017, MacDonald et al. 2019a). Collectively, passive and active surveillance data defined the existing epidemiology of LPDV in wild turkeys; many turkeys are infected but only a small subset develops lymphoid tumors and associated clinical disease. ...
... We tested for avian paramyxovirus serotype-1 (APMV-1) using a commercially available ELISA kit (ProFLOK Newcastle Disease Virus (NDV) Antibody Test Kit; Zoetis, Parsippany, NJ, USA) and influenza A virus (IAV) by agar gel immunodiffusion (Thayer and Beard 2008). We molecularly tested bone marrow samples for proviral DNA of LPDV using PCR targeting a portion of the gag polyprotein (Thomas et al. 2015). None of the turkeys tested for LPDV had any evidence of lymphoid tumors. ...
There are increasing concerns about the effects of disease on wild turkeys (Meleagris gallopavo). Yet, many management agencies lack adequate data on wild turkey diseases and pathogens to address this concern. Toward that end, the Pennsylvania Game Commission increased surveillance efforts on wild turkeys beginning in 2013 (referred to hereafter as the enhanced surveillance period). From 2008–2018, 121 wild turkeys from Pennsylvania were submitted for necropsy, with 102/121 (84.3%) submitted during the enhanced surveillance period (2013–2018). We examined cases to determine causes of morbidity/mortality through gross and microscopic examinations and ancillary tests. The most common causes of morbidity/mortality in the examined wild turkeys were avian pox (66/121; 54.5%), chronic dermatitis (15/121; 12.4%), and trauma (10/121; 8.3%). We diagnosed additional diseases for the first time or more frequently during the enhanced surveillance period, including histomoniasis (7/121; 5.7%) and infectious sinusitis (1/121; 0.8%). Skin lesions were the most common cause of submission (94/121; 77.7%) and were most often attributed to avian pox (66/94, 70.2%), chronic dermatitis (15/94; 16.0%), or lymphoproliferative disease (3/94; 3.2%). During 2013–2018, tissues and sera were collected from any diagnostic cases and hunter‐harvested turkeys to create a tissue repository. We used these samples to test for infection or exposure to specific pathogens. We found that 75.3% (61/81) of wild turkeys were positive for lymphoproliferative disease virus, 61.9% (52/84) for Heterakis gallinarum, 28.6% (10/35) for Toxoplasma gondii, and 15.6% (15/32) for Borrelia burgdorferi. We detected antibodies (indicating exposure) to avian paramyxovirus‐1 in 34.9% (22/63) of the wild turkeys and West Nile virus in 21% (13/62), but none were seropositive to influenza A viruses (0/62; 0%). The presence of diseases and pathogens in wild turkeys in Pennsylvania are being defined through active and passive surveillance approaches. Such data can begin to address the broader questions of disease impacts on wild turkey populations. There are increasing concerns about the effects of disease on wild turkeys (Meleagris gallopavo). Disease data can be obtained through active or passive surveillance. When used in combination, active and passive surveillance provide complementary data on occurrence of diseases in wildlife, as well as the distribution of pathogens and contaminants. We summarized data generated and outline the value of this combined approach for wild turkeys in Pennsylvania.
... The pathogen was first detected in domestic turkeys in Europe and Israel, often resulting in flock mortality greater than 20% Gazit and Yaniv 1999), and the pathogen has been shown to be capable of infecting chickens in experimental settings (Ianconescu et al. 1983). In 2009, LPDV proviral DNA was first identified in a wild turkey in the United States, and subsequent surveys revealed a high prevalence (26-83% by state) and broad distribution across the eastern United States (Allison et al. 2014;Thomas et al. 2015;Alger et al. 2017), and Canada (MacDonald et al. 2019a, 2019b. Although surveillance of hunter-harvested wild turkeys suggested 100% of LPDV-infected turkeys may be outwardly asymptomatic (Thomas et al. 2015), other studies have reported neoplastic lesions in ~15% of clinically-ill birds infected with LPDV (Allison et al. 2014). ...
... In 2009, LPDV proviral DNA was first identified in a wild turkey in the United States, and subsequent surveys revealed a high prevalence (26-83% by state) and broad distribution across the eastern United States (Allison et al. 2014;Thomas et al. 2015;Alger et al. 2017), and Canada (MacDonald et al. 2019a, 2019b. Although surveillance of hunter-harvested wild turkeys suggested 100% of LPDV-infected turkeys may be outwardly asymptomatic (Thomas et al. 2015), other studies have reported neoplastic lesions in ~15% of clinically-ill birds infected with LPDV (Allison et al. 2014). However, coinfection of LPDV with other pathogens was also reported (Allison et al. 2014;MacDonald et al. 2019aMacDonald et al. , 2019b, raising concerns that LPDV infection may increase susceptibility to other pathogens and induce subsequent disease symptoms. ...
... Current sampling for LPDV diagnostics relies on sampling of blood from live-captured turkeys (Alger et al. 2015), or collection of tissue from dead turkeys (Thomas et al. 2015). The blood's separated buffy coat layer (white blood cells) is the standard sample type for antemortem detection of LPDV in a genetic-based assay (Alger et al. 2015), whereas bone marrow is typically used for postmortem detection (Thomas et al. 2015). ...
Widespread wild turkey reintroductions in the late 1900s have led to increases in population density and geographic distribution across North America. This rapid population expansion has put them into proximity with closely-related wild and domestic avian species, increasing the risks of pathogen transmission. Lymphoproliferative disease virus (LPDV) is an avian oncogenic retrovirus detected in wild turkeys in 2009, and previously known to infect domestic turkeys. Following its initial detection, surveys reported variable LPDV prevalence across eastern North America with most wild turkeys being asymptomatic, however diagnostic cases revealed 10% mortality of LPDV-infected individuals. Given its recent detection, little is known about LPDV ecology, transmission or evolution in wild turkeys. We sought to evaluate (1) an alternative detection method for surveillance, (2) individual risk factors, (3) fitness effects, and (4) the genetic diversity and evolutionary history of LPDV in Maine’s wild turkeys. From 2017–2020, we collected tissues and associated data from 72 hunter-harvested and 627 live-captured wild turkeys, and attached radiotransmitters to a subset of live-captured females to monitor survival and reproduction. We used PCR to estimate the infection prevalence of LPDV (59%) and reticuloendotheliosis virus (REV; 16%), another oncogenic retrovirus. In a sample subset, we used plate agglutination to determine the prevalence of exposure to the bacteria, Mycoplasma gallisepticum (74%) and Salmonella pullorum (3.4%). We found cloacal swabs are a reliable LPDV detection method for live-captured wild turkeys. Sex, age, and season were significant predictors of LPDV infection, with females, adults, and individuals sampled in spring having a higher infection risk. Furthermore, we found both LPDV and REV infection negatively affected individual fitness by reducing clutch size and weekly hen survival rate, respectively. Finally, LPDV in Maine is characterized by high diversity and weak spatial genetic structure, which we hypothesize may be driven by high mutation rates, intrahost pathogen dynamics, and/or the history of human-induced and natural wild turkey movement across the state. Overall, this study provides valuable insights into LPDV infection, transmission, and evolution in wild turkeys, data which will aid in future disease monitoring and risk assessments to evaluate effects of infection on wild turkey population dynamics.
... All game birds were free-living and not from captive-propagated sources. Tissue samples were collected and processed as previously reported [16]. Bone marrow samples were collected from the tarsometatarsus (ring-necked pheasants and wild turkeys) or tibiotarsus (ruffed grouse and American woodcock) using sterile bone rongeurs, scalpel blade, and forceps. ...
The Borrelia genus contains two major clades, the Lyme borreliosis group, which includes the causative agents of Lyme disease/borreliosis (B. burgdorferi sensu stricto and other related B. burgdorferi sensu lato genospecies), and the relapsing fever borreliosis group (B. hermsii, B. turicatae, and B. parkeri). Other unclassified reptile- and echidna-associated Borrelia spp. (i.e., B. turcica and ‘Candidatus Borrelia tachyglossi’, respectively) do not belong in either of these two groups. In North America, Borrelia spp. from both of the major clades are important pathogens of veterinary and public health concern. Lyme disease is of particular interest because the incidence in the northeastern United States continues to increase in both dogs and humans. Birds have a potentially important role in the ecology of Borrelia species because they are hosts for numerous tick vectors and competent hosts for various Borrelia spp. Our goal was to investigate the prevalence of Borrelia spp. in four free-living species of upland game birds in Pennsylvania, USA including wild turkey (Meleagris gallopavo), ruffed grouse (Bonasa umbellus), ring-necked pheasants (Phasianus colchicus), and American woodcock (Scolopax minor). We tested 205 tissue samples (bone marrow and/or spleen samples) from 169 individuals for Borrelia using a flagellin gene (flab) nested PCR, which amplifies all Borrelia species. We detected Borrelia DNA in 12% (24/205) of samples, the highest prevalence was in wild turkeys (16%; 5/31), followed by ruffed grouse (13%; 16/126) and American woodcock (3%; 1/35). All pheasants (n = 13) were negative. We sequenced amplicons from all positive game birds and all were B. burgdorferi sensu stricto. Our results support previous work indicating that certain species of upland game birds are commonly infected with Borrelia species, but unlike previous studies, we did not find any relapsing fever borreliae.
... Hence, our objectives were to estimate economic value of turkey hunting and compare whether and how the value differs among geographic regions and between hunting seasons. This study is relevant because many states in the southern United States, including Tennessee, have recently documented declines in turkey populations due to unknown causes and are considering investing in research and increased management to sustain populations and hunting opportunities (Thomas et al. 2015, NWTF 2018. Doing so would require an understanding of its public value in economic terms. ...
Wild turkey (Meleagris gallopavo silvestris; hereafter, turkey), hunting is a popular outdoor recreation activity in many states, including Tennessee, USA. Despite its cultural and social significance, economic benefits associated with turkey hunting are largely unknown. Past economic studies either focused on other big game species or provided generic value for big game, and do not offer benefit estimates specific to turkey. We estimated a demand model for turkey hunting trips in Tennessee and quantified per-trip and statewide aggregate value of turkey hunting. We compared the net economic value of turkey hunting trips between hunting seasons (autumn and spring) and wildlife management regions that differ in many aspects including turkey population, hunting regulations, etc. Per person per trip value of turkey hunting ranged between US$34 and US$90 depending on the modeling assumption regarding hunters’ opportunity cost of time. Moreover, estimated value differed among regions and between hunting seasons, with the value of a turkey-hunting trip in the spring season being twice that of the autumn season. Many states in southern United States, including Tennessee, have recently experienced declines in turkey populations and are in need of economic justifications for investment in research and management. Our results are useful to wildlife agencies in characterizing economic benefits of turkey hunting and evaluating the welfare implications of regulations (e.g., closure, reduction in season length) restricting or expanding hunting opportunities.
