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.

Experiment 4. DoseÐresponse study to evaluate effect of dose and inoculation site for NDV (Roakin) infectivity. Fourteen-day-old chickens were divided into eight groups of 10 birds each and placed in separate Horsfall isolation units. Chicks were intranasally inoculated by squirting 100 l containing a 10 2 , 10 3 , and 10 4 ID 50 of NDV (Roakin) into the left nasal passage. Chicks were inoculated orally by passing a no. 5 French catheter into the crop and delivering 1.0 ml containing the calculated dose of 10 4 , 10 6 , and 10 8 infectious units NDV (Roakin). Two control groups of 10 birds were sham inoculated. Birds were observed daily for clinical signs of disease. At day 21 postexposure, blood was collected from six birds in each group; all birds then were humanely euthanatized. Serum was evaluated by hemagglutination inhibition assays for presence of NDV-speciÞc antibodies. The experiment was conducted once.