Detection and Isolation of Exotic Newcastle Disease Virus from Field-Collected Flies

Abstract

Flies were collected by sweep net from the vicinity of two small groups of "backyard" poultry (10 Ð20 chickens per group) that had been identiÞed as infected with exotic Newcastle disease virus (family Paramyxoviridae, genus avulavirus, ENDV) in Los Angeles County, CA, during the 2002Ð2003 END outbreak. Collected ßies were subdivided into pools and homogenized in brain-heart infusion broth with antibiotics. The separated supernatant was tested for the presence of ENDV by inoculation into embryonated chicken eggs. Exotic Newcastle disease virus was isolated from pools of Phaenicia cuprina (Wiedemann), Fannia canicularis (L.), and Musca domestica L., and it was identiÞed by hemagglutination inhibition with Newcastle disease virus antiserum. Viral concentration in positive pools was low (1 egg infectious dose 50 per ßy). Isolated virus demonstrated identical monoclonal antibody binding proÞles as well as 99% sequence homology in the 635-bp fusion gene sequence compared with ENDV recovered from infected commercial egg layer poultry during the 2002 outbreak.