Submitted to: Livestock Insect Worker's Conference Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/2006
Publication Date: 6/25/2006
Citation: Chakrabarti, S., King, D.J., Cardona, C., Afonso, C.L., Swayne, D.E., Gerry, A.C. 2006. Potential role of flies in the persistence and dispersal of exotic Newcastle disease virus in Southern California [abstract]. Livestock Insect Worker's Conference Annual Meeting. p. 34.
Technical Abstract: Exotic Newcastle Disease (END) is a highly virulent and contagious disease affecting poultry and other birds with the potential of causing 100% mortality in unvaccinated poultry. Transmission of END virus to susceptible birds is primarily thought to occur via direct contact with infected birds or infective fecal material. However, indirect transmission of this virus is known to occur. During a 1971-1973 END outbreak flies in the genus Fannia sampled from END virus contaminated premises were found to harbor the virus, thereby implicating them in the persistence or dispersal of the virus. During the 2002 END outbreak arthropods were collected from two quarantined backyard poultry premises in Southern California after removal of birds infected with END virus. The arthropod collection was subdivided into pools which were homogenized and the separated supernatant fluids were tested for the presence of the virus by embryonated chicken egg inoculation. END virus was isolated from field collected pools of Phaenicia cuprina, Fannia cannicularis, and Musca domestica. The isolated viruses were identified by hemagglutination inhibition (HI) with Newcastle disease virus antiserum and were shown to have >98% homology by nucleotide sequence analysis and identical monoclonal antibody binding profiles to viruses recovered from poultry during the 2002 outbreak. Two fly species, Musca domestica and Fannia cannicularis, commonly associated with poultry operations were choice fed with California 2002 END virus for 24 hrs and sampled daily for the presence of virus through day-9 and day-12 post-infection respectively. In the experimental flies, the virus was recovered through days 4-5 in M. domestica and through days 7-8 in F. cannicularis. This study clearly suggests that flies have the capacity to harbor live virus for time periods long enough to disperse the virus from an infected poultry facility to another uninfected facility. These findings suggest biosecurity measures should include an aggressive vector control program on and near infected premises to minimize possible contact between flies from contaminated poultry premises and susceptible poultry as part of the END eradication effort.