In nature, disease-causing strains of avian influenza rarely spread far because the birds sicken and die before they can fly to spread it to others. — Michael Greger Copy Share Image
The emergence and spread of virulent strains of avian influenza has been attributed by experts to the intensely overcrowded, unsanitary, and stressful conditions that often characterize large-scale factory farming in industrialized agriculture. — Michael Greger Copy Share Image
