Tuesday, October 11, 2011

Contagion and Doctor Wolfe

The film “Contagion” had its initial genesis in a TED talk presentation by Larry Brilliant.  In this presentation, Brilliant notes he did a survey of people that work in the field of epidemiology and asked them what the results and likelihood of a pandemic viral outbreak like the 1918 Spanish Flu outbreak today.  The general prognosis was that 1 billion people would die, and that there was a 15% chance of occurrence within 3 years, and an 85% chance within the lifetime of our grandchildren.  The disruption caused by the pandemic would bring the world’s economy to a screeching halt.

Caleb Hellerman, CNN Health, 13 September 2011

[The film] uses a concept known as "R0" -- pronounced "R-naught"--- to explain to skeptical public health officials that the new virus could be much more contagious than influenza or polio.

"I wanted people to understand R0," explains Scott Z. Burns, who wrote the film, which was No. 1 at the box office this weekend. Here it is: R0 is the number of new cases that a single infected person will cause, on average. In most seasons, R0 for influenza is just below 2. In the devastating 1918 pandemic, it was likely above 3. With an R0 that high, the number of cases will grow exponentially, unless patients remain isolated or quickly receive effective treatment…

CDC not only allowed filmmakers to spend a day shooting "on campus," but senior scientists spent a day with Winslet to help her prepare for the role. Winslet's main guide at CDC was Dr. Anne Schuchat, who led the agency's response to the H1N1 pandemic.

"In my discussions, the key thing I wanted to get across was the intensity of these investigations, the focus you give and the 24/7 nature of it," says Schuchat. "You're disconnected from your regular life, and totally immersed in what you're doing."….

"On the one hand, writing it did freak me out. I wanted to be realistic, and I kept asking these scientists, 'Could this or that scenario really happen?' And they always said, 'Sure, it could happen.' On the other hand, I was reading an article two years ago, and it talked about how human DNA is littered with remnants of our battles with retroviruses. There's something poetic about that. So with people and viruses, when you look at in the longevity of the relationship, there's some comfort."

So what he found comfort in was the numerous previous battles that are recorded in our genetic code, and the fact that we are still around.  I am curious as to Mr. Burn’s understanding of survivor bias.

A follow up on the contagion piece, was an article written

Nathan Wolfe, Wall Street Journal, 8 October 2011

We need a different approach, based on our growing capacity to predict the most serious threats and to keep them from spreading. Pandemics do not occur randomly. From malaria and influenza to AIDS and SARS, the lethal microbes have come, in the first instance, from animals, especially wild animals. And we increasingly know which parts of the world pose the greatest risk for future incursions.
One of the keys to such surveillance, we found, was to focus on perhaps the most direct interface between humans and wild animals: "bushmeat." Bushmeat is another word for wild game, and it is crucial to the local diet in many parts of central Africa. Where domestic protein sources are scarce, animals ranging from guinea fowl and pythons to monkeys and porcupines often take their place. Collectively, these wild animals harbor an enormous universe of microbes, which can provide fodder for pandemics.
Animals like the mandrill, eaten as bushmeat, harbor diseases that can jump to humans.

We also looked into the ways that the people of these villages interacted with wildlife. In a study coordinated by Adria Tassy Prosser, an anthropologist and epidemiologist now based at the Centers for Disease Control in Atlanta, we learned that the villagers had an incredibly intimate level of contact with wild animals. The process of butchering gave them direct exposure to virtually all of the blood and body fluids that viruses call home. As we expected, people engaged in hunting and butchering were at the front line of viral transmission from animals to humans.
Doctor Wolfe wants to set up a global resource center to track all of these possible interactions and contagions.  He does not address the issue that, much like forest fires, stopping many small contagious events often leads to really really big ones down the road.  But it somewhat begs the question of who is going to pay for this in any case.

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