Molecular Characterization of Vaccine-Derived Mutants of Avian Meta-Pneumoviruses Isolated from Turkeys in Egypt

Avian metapneumovirus (aMPV) causes acute respiratory infection in turkeys with sudden onset and rapid spread in the infected flocks. Vaccinated flocks frequently showed clinical signs typical like the non-vaccinated flocks in Egypt, this situation suggests a virulent vaccine virus was circulating in the field. Oropharyngeal and nasal sinus swabs were collected from 100 turkeys from 10 commercial farms with mild to moderate respiratory signs....