Turkey rhinotracheitis outbreak caused by the environmental spread of a vaccine derived avian metapneumovirus

Caterina Lupini (1) , Mattia Cecchinato (2) , Enrico Ricchizzi (3) , Clive J Naylor (4) , Elena Catelli (3)

1 Dipartimento di Scienze Mediche Veterinarie
2 Dipartimento di Sanità Pubblica, Patologia Comparata e Igiene Veterinaria
3 Dipartimento di Scienze Mediche Veterinarie
4 Department of Infection Biology

Avian metapneumovirus (AMPV) subtype A was isolated from seven-week-old turkeys showing respiratory disease typical of turkey rhinotracheitis (TRT). Comparison of the virus sequence to 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 six months nor had it been used on farms within a distance of approximately five kilometres. 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 which was present in the environment and indicates that such virus is able to circulate for longer than was previously envisaged.

Mots clés: Life Sciences

Domaines: Biologie animale

Caterina Lupini, Mattia Cecchinato, Enrico Ricchizzi, Clive J Naylor, Elena Catelli. Turkey rhinotracheitis outbreak caused by the environmental spread of a vaccine derived avian metapneumovirus. Avian Pathology, 2011, pp.1. ⟨10.1080/03079457.2011.607428⟩. ⟨hal-00724185⟩