‘Grossly irresponsible’: health experts urge US to control bird flu
卫生专家敦促美国加强抗击禽流感疫情

Call for stronger action comes on warning of growing risk the virus will evolve to spread more easily between humans
H5N1病毒在美国传播逾9个月之际，病毒学家担心其遗传物质会与人类流感病毒发生基因重配，产生一种更容易人传人的新病毒。