|
|||||
|
|
A turkey rhinotracheitis outbreak caused by the environmental spread of a vaccine-derived avian metapneumovirus |
|
| Authors: | Caterina Lupini Mattia Cecchinato Enrico Ricchizzi Clive J Naylor Elena Catelli |
| Institution: | 1. Dipartimento di Scienze Mediche Veterinarie , Alma Mater Studiorum—University of Bologna , Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy caterina.lupini@unibo.it ;2. Dipartimento di Sanità Pubblica, Patologia Comparata e Igiene Veterinaria , Faculty of Veterinary Medicine, University of Padua , Viale dell'Università 16, 35020, Legnaro, PD, Italy;3. Dipartimento di Scienze Mediche Veterinarie , Alma Mater Studiorum—University of Bologna , Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy;4. Department of Infection Biology, Institute of Infection and Global Health , Faculty of Health and Life Sciences, Leahurst Campus, University of Liverpool , Liverpool, CH64 7TE, UK |
| Abstract: | Avian metapneumovirus (aMPV) subtype A was isolated from 7-week-old turkeys showing respiratory disease typical of turkey rhinotracheitis. Comparison of the virus sequence with previously determined vaccine marker sequences showed that the virulent virus had originated from a licensed live subtype A aMPV vaccine. The vaccine had neither been in use on the farm within a period of at least 6 months nor had it been used on farms within a distance of approximately 5 km. Isolation of the virus and exposure to naive turkeys caused disease typical of a virulent aMPV field strain. The study shows that disease was caused by exposure to aMPV vaccine-derived virus that was present in the environment, and indicates that such virus is able to circulate for longer than was previously envisaged. |
| Keywords: | |