TED Conversations

Christine O'Connor

This conversation is closed.

Can we control the emergence of zoonotic infectious disease?

Seventy five percent of the world’s emerging infectious diseases are zoonotic, or animal, in origin. Familiar examples include HIV/AIDS, Ebola, SARS, Lyme disease and West Nile Virus.

Humans play a big part in the emergence and spread of these and other infectious diseases. Our ever-expanding encroachment on forests – due to deforestation and increases in bushmeat hunting – increases the potential for disease transmission from animals to humans. Urbanization and global travel more easily allow for the spread of a disease from person to person and across the globe. These factors combine to greatly increase the probability of successful emergence and spread of an infectious disease.

Despite the clear importance understanding and controlling zoonotic diseases we have not had much success eradicating them, or even limiting their spread. It is hard to eradicate what we can’t find. Fore example, despite many years of study, researchers still are not sure where Ebola comes from. Outbreaks can be traced to handling of dead chimpanzees and gorillas, but neither appears to be the reservoir host (a species that is a source of infection but not affected by the disease) for Ebola.

What should be done to stop or control the emergence and spread of these diseases before they become global pandemics? Should we try and limit close contact with wild animals, perhaps via habitat preservation? Should we better control the bushmeat trade and/or educate hunters and consumers of bushmeat and other types of wild animal markets of the risks involved with such meat? Or, is a more proactive approach possible? Is there a way to pre-emptively identify such emerging diseases, via monitoring of wild animals and those who regularly have close contact with them?

Souce: Spillover by David Quammen

Also see: Q&A on swine flue with virus hunter Nathan Wolfe "We've created the perfect storm for viruses" http://blog.ted.com/2009/04/28/qa_with_virus_h/


Showing single comment thread. View the full conversation.

  • thumb
    Jun 5 2013: In population ecology, one of the first models taught is the density-independent, exponential growth model, where a population exhibits continued geometric growth. While this type of growth is present in real life, it often only occurs for short periods of time because the growth is so rapid it is unsustainable and eventually something becomes limiting. However, this is the type of growth demonstrated by the human population so far. Have we exceeded our carrying capacity? Or have we increased it by inventing ways to create more food or extract more resources? Either way it cannot be maintained at this rate for much longer.

    In Alan Hastings’ book, Population Biology: Concepts and Models, he lists several hypotheses for mechanisms of population regulation, one of which is parasites and diseases.

    Perhaps the emergence of zoonotic pathogens is just form of population regulation that nature is inducing on the human population. Maybe we won’t be able to suppress it, or maybe by suppressing it we are only buying more time until another mechanism begins to kick in?

    this blog post discusses relationships between overpopulation and the emergence of diseases, but I think Gwynne in particular might like the last paragraph where he questions if overpopulation is the cause of emergence, or over consumption by industrialized nations.


Showing single comment thread. View the full conversation.