DIAGNOSING LYMPHOPROLIFERATIVE DISEASE VIRUS IN LIVE WILD TURKEYS (MELEAGRIS GALLOPAVO) USING WHOLE BLOOD.

Lymphoproliferative disease virus (LPDV) is a retrovirus that infects wild and domestic turkeys ( Meleagris gallopavo ). The first cases of LPDV in the United States were diagnosed in 2009, and subsequent surveillance has revealed the virus to be widespread in wild turkey populations throughout the eastern half of the country. More research is needed to determine whether LPDV is having a negative effect on turkey populations, but progress has been impeded by the lack of a simple method for diagnosing the virus in living birds. Infected animals may appear asymptomatic, and diagnostics currently rely on tissue or bone marrow, which can be difficult to obtain. This study investigated the reliability of polymerase chain reaction (PCR) to detect LPDV in whole blood, compared with previous methods using buffy coat (concentrated white blood cells) and bone marrow. Paired samples of whole blood and buffy coat were collected from 137 live turkeys and paired samples of whole blood and bone marrow were collected from 32 turkeys postmortem. Compared with buffy coat, whole blood had 97% sensitivity and 100% specificity. When compared with bone marrow, whole blood had 100% sensitivity and 89% specificity. Both comparisons had a high degree of agreement using Cohen's kappa statistic. Based on these results, PCR of whole blood provides detection of LPDV in living birds that is on par with both buffy coat and bone marrow.

Inactivation of Viable Surrogates for the Select Agents Virulent Newcastle Disease Virus and Highly Pathogenic Avian Influenza Virus Using Either Commercial Lysis Buffer or Heat.

Introduction: Federal Select Agent Program regulations require laboratories to document a validated procedure for inactivating select agents prior to movement outside registered space. Avian influenza viruses and virulent Newcastle disease virus (vNDV) are cultured in chicken amnio-allantoic fluid (AAF), but the efficacy of commercial lysis buffers to inactivate viruses in protein-rich media has not been documented. Objectives: We assesses the efficacy of MagMAX™ lysis buffer for inactivating highly pathogenic avian influenza virus (HPAIV) and vNDV in chicken AAF and confirm the inactivation of avian influenza in serum using heat. Methods: Low pathogenic avian influenza virus (LPAIV) and avian paramyxovirus subtype-1 (APMV-1) were incubated with lysis buffer and tested for viability. Known viable LPAIV and APMV-1 RNA was extracted from AAF using MagMAX™-96 AI/ND Viral RNA Isolation kit, and the eluate was tested for remaining infectious agent. Finally, inactivation of LPAIV in serum was examined over 3 combinations of temperature and incubation time. Results: MagMAX™ lysis buffer inactivated both LPAIV and APMV-1 in AAF when incubated for 30 minutes at room temperature. The full extraction process eliminated viable virus from the final RNA eluate. LPAIV in serum heated to 70°C for 30 minutes was rendered noninfectious. Conclusion: The ability of a diagnostic laboratory to move samples from one space to another is critical to maintaining biosecurity as well as efficient laboratory workflow. Our study demonstrates a method to ensure the inactivation of viable avian influenza and avian paramyxoviruses in AAF, RNA eluate, and viable avian influenza virus in sera.

RISK FACTORS FOR AND SPATIAL DISTRIBUTION OF LYMPHOPROLIFERATIVE DISEASE VIRUS (LPDV) IN WILD TURKEYS (MELEAGRIS GALLOPAVO) IN NEW YORK STATE, USA.

Lymphoproliferative disease virus (LPDV) is an oncogenic avian retrovirus that was previously thought to exclusively infect domestic turkeys but was recently shown to be widespread in Wild Turkeys ( Meleagris gallopavo ) throughout most of the eastern US. In commercial flocks, the virus spreads between birds housed in close quarters, but there is little information about potential risk factors for infection in wild birds. Initial studies focused on distribution of LPDV nationally, but investigation of state-level data is necessary to assess potential predictors of infection and detect patterns in disease prevalence and distribution. We tested wild turkey bone marrow samples (n=2,538) obtained from hunter-harvested birds in New York State from 2012 to 2014 for LPDV infection. Statewide prevalence for those 3 yr was 55% with a 95% confidence interval (CI) of 53-57%. We evaluated a suite of demographic, anthropogenic, and land cover characteristics with logistic regression to identify potential predictors for infection based on odds ratio (OR). Age (OR=0.16, 95% CI=0.13-0.19) and sex (OR=1.3, 95% CI=1.03-1.24) were strong predictors of LPDV infection, with juveniles less likely to test positive than adults, and females more likely to test positive than males. The number of birds released during the state's 40-yr translocation program (OR=0.993, 95% CI=0.990-0.997) and the ratio of agriculture to forest cover (OR=1.13, 95% CI=1.03-1.19) were also predictive of LPDV infection. Prevalence distribution was analyzed using dual kernel density smoothing to produce a risk surface map, combined with Kulldorff's spatial scan statistic and the Anselin Local Moran's I to identify statistically significant geographic clusters of high or low prevalence. These methods revealed the prevalence of LPDV was high (>50%) throughout New York State, with regions of variation and several significant clusters. We revealed new information about the risk factors and distribution of LPDV in New York State, which may be beneficial to game bird managers and producers of organic or pasture-raised poultry.