ABSTRACT
In order to study the regularity of shedding virus from infected SPF chickens and the formation of aerosol of H9N2 subtype AIV, SPF chickens were bred in a positive and negative pressure isolator. Aerosol samples were collected by AGI-30 (All Glass Impinger-30) extractor, and simultaneously trachea and cloaca samples were collected by tracheal swabs and cloacal swabs in different periods after challenged with vi- ruses. The above-mentioned samples were detected by HI, Dot-ELISA and RT-PCR methods. The results in- dicated that aerosols were isolated from the 4 days to the 43 days after inoculation. It was proved that H9N2 subtype AIV could copy themselves in respiratory passage and cloaca, and then could formation of aerosols. AIV H9N2 subtype could be isolated from cloacal and tracheal swabs 3 days after inoculation and lasted for 45 days, viruses were detected from all infected SPF chickens on 7 days.