Alger Katrina, Bunting Elizabeth, Schuler Krysten, Whipps Christopher M
1 State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, 246 Illick Hall, Syracuse, New York 13210, USA.
2 New York State Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, 240 Farrier Road, Ithaca, New York 14853, USA.
J Wildl Dis. 2017 Jul;53(3):499-508. doi: 10.7589/2016-06-137. Epub 2017 Mar 22.
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.
淋巴增生性疾病病毒（LPDV）是一种致癌性禽逆转录病毒，以前认为它只感染家火鸡，但最近发现它在美国东部大部分地区的野生火鸡（Meleagris gallopavo）中广泛存在。在商业鸡群中，该病毒在饲养密度大的禽类之间传播，但关于野生鸟类感染潜在风险因素的信息很少。最初的研究集中在LPDV在全国的分布情况，但有必要调查州一级的数据，以评估感染的潜在预测因素，并检测疾病流行率和分布模式。我们检测了2012年至2014年从纽约州猎人捕获的野生火鸡身上获取的骨髓样本（n = 2538）是否感染LPDV。这3年全州的感染率为55%，95%置信区间（CI）为53 - 57%。我们使用逻辑回归评估了一系列人口统计学、人为因素和土地覆盖特征，以根据优势比（OR）确定感染的潜在预测因素。年龄（OR = 0.16，95% CI = 0.13 - 0.19）和性别（OR = 1.3，95% CI = 1.03 - 1.24）是LPDV感染的强预测因素，幼鸟检测呈阳性的可能性低于成年鸟，而雌鸟检测呈阳性的可能性高于雄鸟。该州40年的易地放归计划中释放的鸟类数量（OR = 0.993，95% CI = 0.990 - 0.997）以及农业与森林覆盖面积的比例（OR = 1.13，95% CI = 1.03 - 1.19）也可预测LPDV感染情况。使用双核密度平滑法分析流行率分布，以生成风险表面图，并结合Kulldorff空间扫描统计量和Anselin局部莫兰指数（I）来识别高流行率或低流行率的具有统计学意义的地理集群。这些方法显示，纽约州各地LPDV的流行率很高（>50%），存在差异区域和几个显著的集群。我们揭示了纽约州LPDV的风险因素和分布的新信息，这可能对猎禽管理者以及有机或牧场饲养家禽的生产者有益。
