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

Chakrabarti, Seemanti; King, Daniel J.; Afonso, Claudio; Swayne, David; Cardona, Carol J.; Kuney, Douglas R.; Gerry, Alec C.

Although all ßy species were collected in small numbers, ENDV was isolated from the three most abundant species collected during this study. This is the Þrst report of ENDV isolated from Þeld-collected P. cuprina and M. domestica; ENDV had previously been isolated from F. canicularis and Fannia femoralis (Stein) from a commercial poultry operation during the 1971 END outbreak (Rogoff et al. 1975) . Given the small numbers of ßies collected, the prevalence of ENDV-infected ßies was high with Ϸ30% of the pools containing the three species mentioned above having one or more ßies per pool infected with virus. The virus prevalence in Fannia spp. collected from commercial poultry operations during the 1971 END outbreak was far lower with only two of 78 pools of Fannia spp. (3,926 total ßies) collected before or within 2 d of poultry removal containing ENDV, and no virus was recovered from other common ßy species (Rogoff et al. 1975) . It is unclear to what extent Rogoff et al. (1975) may have collected ßies from poultry facilities where poultry or even manure had already been removed from the site, perhaps resulting in the much lower ENDV infection prevalence in ßies relative to this study. The higher ENDV prevalence in this study also may be due to differences between commercial poultry and backyard poultry in animal housing, manure handling, or vaccination status of the poultry against Newcastle disease virus. Backyard poultry are often housed together on the ground or in wooden boxes, giving them greater access to an infected bird and its manure relative to commercial egg-layer poultry that are separated into cages suspended above the ground where the manure is allowed to accumulate. Additionally, backyard poultry are usually not vaccinated against Newcastle disease virus and infected