A real life 'Contagion': Humans may be to blame for viruses jumping from animals to us

The risk of new viruses jumping from animals to humans was highest from threatened wild animals that have declined due to exploitation and habitat destruction.

(CNN)It could be a real-life "Contagion," much like the movie.

As a deadly pandemic spreads across the globe, a timely new study has identified key drivers of "virus spillover" from mammals to humans.
The risk of virus spillover -- when viruses jump from animals to humans -- was highest when human exploitation and habitat destruction threatened wild animals, according to a data analysis conducted by researchers at the University of California and the University of Melbourne.
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    The research was carried out years before the current pandemic began, but researchers have long expected "emerging infectious diseases that come from wildlife and affect people," said study author Dr. Christine Kreuder Johnson, a professor of epidemiology and wildlife health at the University of California, Davis.
    "The reason why we did this work was to help understand what are the drivers for spillover, " she said, and what characteristics appeared in the past "that can help us [prevent spillover] in the future."

    Transmission of zoonotic disease

    A zoonotic disease is a disease spread between animals and people, and they can be caused by bacteria, parasites, fungi and viruses, according to the US Centers for Disease Control and Prevention.
    Some animal-borne diseases may have adapted and transferred easily to humans because the biological makeup of the mammal was similar to that of a human.
    Transfer is also easier if the human and the species have lived together over time, which is typically the case in humans infected with zoonotic disease from pigs and livestock, Johnson said. That's because humans have farmed them for food and lived with or near them for centuries.
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