科学与发展网络(SciDev.Net)

Dense pig populations, such as those found in food factories, allow viruses to spread and evolve very quickly

Flickr/Farm Sanctuary

What makes us so susceptible to pandemics, asks Sunita Narain, editor of the Indian science magazine Down to Earth. The answer, she says, is linked to the way we produce food.

The current swine flu outbreak originated in the small town of La Gloria, Mexico, which lies next to one of the country's biggest pig factories. The factory's owner, Smithfield Foods, claims their herds are healthy — but they have not shared the supporting data.

Virologists have confirmed that the current strain of swine flu is the same as that first identified on industrial pig farms in North Carolina in 1998 — a hybrid virus containing swine, bird and human gene segments. It is thought that, sometime in March, this hybrid got mixed with a common flu virus to create a new strain.

Narain argues that dense pig populations, such as those found in food factories, allow viruses to spread and evolve very quickly. When avian flu broke out a few years ago, similar concerns about intensive poultry farming were raised.

Link to full article in Down to Earth