Table 2.

Pathogenicity of H7N9 and related viruses in BALB/c mice

Virus	Subtype	Weight loss†	Lung titre (d 3)‡	Lung titre (d 6)‡	MID50§	LD50§
Anhui/1	H7N9	22.2 (7)	7.2 ± 0.6	5.5 ± 0.5	0.25	3.4
Shanghai/1	H7N9	25.6 (4)	6.6 ± 0.2	5.6 ± 0.2	0.25	3.3
shv/Egypt/07	H7N9	16.5 (3)	4.4 ± 0.2	5.6 ± 0.3	2.25	>6
ck/VN/11	H9N2	18.1 (6)	4.8 ± 0.2	3.1 ± 0.1	1.5	>6

†Maximum per cent weight loss (5 mice per group) after infection with 10⁶ p.f.u. of virus (day p.i. in parentheses).

‡Average lung titres of three mice on indicated days p.i., expressed as log₁₀ (p.f.u. ml⁻¹) ± SD.

§MID₅₀ and LD₅₀ are expressed as the log₁₀ p.f.u. ml⁻¹ required to give one MID₅₀ or one LD₅₀.