After 48h post-inoculation, virions were observed in allantoic fluid from artificial infection SPF chicken embryos with isolated virus by electron microscope with negative staining.

• 病毒生物学特性试验表明，该病毒为RNA病毒，通过尿囊腔接种，可在10日龄SPF鸡胚上生长，接种后3-5天可引起鸡胚规律性死亡，病毒在10日龄SPF鸡胚上增殖的高峰为接种后72h。