Pairwise comparison of LPDV detected (+) and undetected (-) samples using the <i>gag</i> and LTR sections of the provirus.

Pairwise comparison of LPDV detected (+) and undetected (-) samples using the gag and LTR sections of the provirus.</p

CSV file containing the Wild Turkey LPDV infection status dataset.

CSV file containing the Wild Turkey LPDV infection status dataset.</p

S1 File -

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, pLTR 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.</div

Evaluation of LTR as a diagnostic test for LPDV infection against the standard (<i>gag</i>) using positive percent agreement (PPA), negative percent agreement (NPA), Cohen’s kappa, and McNemar’s odds ratio (OR).

Evaluation of LTR as a diagnostic test for LPDV infection against the standard (gag) using positive percent agreement (PPA), negative percent agreement (NPA), Cohen’s kappa, and McNemar’s odds ratio (OR).</p