SIR – Swine influenza A (H1N1) has probably now killed more than 150 people in Mexico and is spreading around the world.

This virus – which contains segments of both avian flu and human flu – is the latest in a long line of devastating diseases caused by farming animals.

Dr Michael Greger, an expert in bird flu, writes that tuberculosis is thought to have been acquired from the domestication of goats; measles and smallpox from farming cows; whooping cough from pigs; and typhoid fever from chickens.

And we shouldn’t be surprised. It is naive to imagine that we can incarcerate animals inside crowded, filthy factory farms without them suffering a high level of infectious diseases.

Who knows how many millions of people have suffered and died because we choose to farm animals and eat their meat, milk and eggs? That this outbreak of swine flu has the potential to cause another human pandemic is a serious wake-up call.

To prevent future disease outbreaks and the deaths of millions more people, the only sane answer is to stop farming animals.

Anyone interested in adopting a meat-free diet can order a free pack from or (01732) 364546.

Kate Fowler, head of campaigns, Animal Aid, The Old Chapel, Bradford Street, Tonbridge, Kent