Experimental Evaluation of Musca domestica (Diptera: Muscidae) as a Vector of Newcastle Disease Virus

Watson, D. Wes; Niño, Elina L.; Rochon, Kateryn; Denning, Steve; Smith, Lynda; Guy, James S.

Subsequent experimentation to establish an infectious dose necessary for oral exposure indicated that NDV Roakin, when administered by oral gavage at 10 4 ID 50 of virus, was insufÞcient to cause infection (Table 3) ; only those birds inoculated with a dose Ն10 6 ID 50 became infected. These Þndings suggest that NDV transmission, in the current study, failed because chicks failed to ingest an adequate quantity of virusladen ßies; based on calculations chicks would have needed to consume Ͼ33 ßies to reach a sufÞcient dose for infection by the oral route. However, intranasal inoculation at 10 4 ID 50 infected 100% of the chicks. Although the house ßy did not transmit NDV in our study, the potential to mechanically transmit NDV remains a possibility because NDV was detectable in both crop and gut tissues for up to 96 and 24 h, respectively, postfeeding (Tables 1 and 2) .