Transboundary and Emerging Diseases

Research Article

Genetic Diversity and Biological Characteristics of H3 Avian Influenza Virus Isolated from China in 2021–2022 Showed the Emerging H3N8 Posed a Threat to Human Health

Table 2

Virulence of H3 viruses in chickens.^a


Viruses	Virus shedding (log₁₀EID₅₀) (positive/total)						Death/total	Seroconversion (HI antibody titers) (positive/total)
	2 dpi		4 dpi		6 dpi
	Pharynx	Cloacae	Pharynx	Cloacae	Pharynx	Cloacae

DK/JX/E1137/2021(H3N8)	<	2.75 (1/8)	<	5.5 (1/8)	<	1.25 (1/5)	0/5	2 (1/5)
DK/GD/G1202/2022(H3N2)	3.5 (1/8)	3.5 (1/8)	2.7 ± 0.90 (4/8)	5.75 (1/8)	<	1.25 (1/5)	0/5	2–8 (4/5)
CK/NX/N1053/2022(H3N8)	4.47 ± 0.86	1.25 (1/8)	4.22 ± 1.72	1.46 ± 0.17 (7/8)	1.75 ± 0.66 (3/5)	2.83 ± 2.32 (3/5)	0/5	8–32 (5/5)
GS/JX/E1427/2022(H3N8)	4.78 ± 0.76	1.38 ± 0.18 (2/8)	4.72 ± 0.34	1.38 ± 0.18 (2/8)	1.5 ± 0.35 (2/5)	<	0/5	16–32 (5/5)

^aGroups of eight chickens were inoculated with 10^6.0 EID₅₀ per 0.1 ml of test virus. All chickens were monitored daily for clinical signs. Pharyngeal and cloacal swabs were taken from live chickens at 2, 4, 6, and 8 days postinfection (dpi). <, No virus was detected in this sample.