According to Reuters, 161 people have died from bird flu in China since October.

The data highlights the scale of the spread of the virus among humans, even after Chinese disease control experts have warned the public to stay on alert. South Korea and Japan are also battling their own major outbreaks and have culled millions of chickens.

The H7N9 strain shows little or no symptoms in poultry, a factor which has limited the number of birds culled in the world’s third-largest producer of broiler chickens and the second-biggest consumer of poultry.