Ecology, modeling, and control of avian metapneumovirus infections.

摘要

Avian metapneumovirus (aMPV) is an agricultural pathogen of great economic importance. The viral infection was first recognized in the 1970's in Africa, but it wasn't until 1996 that the first outbreak occurred in the United States and was officially diagnosed the following year. The clinical disease is characterized by sneezing, coughing, nasal discharge, and a transient drop in egg production in laying birds. Avian MPV infections are often accompanied by secondary bacterial infections which lead to carcass condemnation at the processing plant. Here we describe the first broad survey of domestic turkeys for evidence of infection and determined the endemic area of the virus has grown. In addition to domestic birds, samples were collected from over 1500 wild birds to determine the role that they play in the ecology of aMPV. It appears wild birds may serve as both a natural reservoir and mechanical vector capable of moving virus between farms. We were able to isolate infectious virus from juvenile Canada geese, which contained a genome of similar organization to other subtype C aMPVs, but interestingly contained a much larger attachment glycoprotein then turkey derived isolates. This isolate was infectious to domestic turkeys, but did not induce clinical disease even in birds infected at hatch. This strain functions as a Jennerian type vaccine and affords protection against virulent challenge.