House flies (Musca domestica spp.) are one of the major pests, especially in the poultry farms resulting in not only annoyance and indirect damage to their production but also transmitting many infectious organisms mechanically and biologically. Wuryastuty et al. (2008) have fully succeeded in identification and isolation of highly pathogenic avian influenza virus H5N1 (AIV H5N1) from collected field house flies in Java Island, Indonesia. The AIV H5N1 isolates mentioned were further used to study the presence and persistence of the AIV H5N1 in the laboratory infected Musca domestica spp. One hundred house flies from a free AIV poultry farm in Yogyakarta, Indonesia were used in this study. The collected house flies were fasted for 12 hours and divided equally into the control and treated groups. The treated group was allowed to imbibe medium containing AIV H5N1 while the control group imbibed medium without virus for 1 hour. The flies from each group were collected 12 and 24 hours post exposure, respectively, immobilized at 4°C, immersed in absolute alcohol ethanol for a few second and dissecting under stereo microscope to collect the gastro-intestinal (GI) tract of the flies. Results showed that AIV H5N1 was first detected molecularly in dissected GI tract of the house flies and the viruses remained viable 24 hours after exposure. It is concluded that the house flies could be as AIV H5N1 vector mechanically and/or biologically.

Keywords: house flies (Musca domestica spp.), mechanical and/or biological vector, avian influenza virus H5N1