The Viral Storm (22 page)

Whatever the route of infection, the findings from the Dja and from the earlier animal epidemic in the Ivory Coast showed that the declining populations of African apes had more than hunting and habitat loss to blame. Viruses like Ebola have swept through large swaths of the remaining habitats of wild apes, and now anthrax must also be considered a threat to these valuable wild animals. From a personal perspective, having worked with wild chimpanzees and helped habituate populations of gorillas in Uganda, I feel that the mounting threats to our closest living relatives is a tragic loss to the heritage of our particular form of life.

Gorilla killed by anthrax in the Dja Biosphere Reserve, Cameroon.
(
Matthew LeBreton
)

From the perspective of my work tracking and preventing pandemics, the deaths pointed out another glaring weakness in the way that we catch these epidemics. The discovery of anthrax in the Dja forest did not represent a success in pandemic prevention. It was rather the epidemiological equivalent of dumb luck. Only a trivial fraction of the global ape populations are under the watchful eye of woefully underfunded primatologists. If we’re relying on these scientists to regularly capture the animal epidemics that could signal future human plagues, then we’re destined to fail. To truly catch epidemics early, we’ll need much more.

*   *   *

How can we hunt down deadly viruses and control them? A few primatologists finding dead animals is not a surveillance system. But what is the right way to catch new epidemics and stop them before they spread? This section will explore just that: the contemporary science of pandemic prevention. It will discuss the ways that my team and other colleagues and collaborators are working to create systems that will be able to catch and stop new epidemics before you (or CNN) even know about them. Preventing pandemics is a bold idea, yet no bolder than when cardiologists in the 1960s began to think that they could prevent heart attacks, a medical advance that was radical at the time but is now largely taken for granted.

My own thinking on this dates to the late 1990s when I joined Don Burke at Johns Hopkins and agreed to establish a field site aimed at monitoring humans and animals for new viruses in central Africa. It was an exciting time, when the idea that simply responding to pandemics would no longer be sufficient was truly in the air. I remember spending many afternoons in Don’s office alternating between urgent scribbling on the whiteboard and thinking out loud about what would be needed to accomplish the task.

Among the ideas that we generated during that time, one lasting concept particularly stands out:
viral chatter
. When he coined the term, Don did so as a direct parallel to
intelligence chatter
. One way of thinking about this is to ask the question: how do security services prevent terror events?

Intelligence services use a range of techniques to monitor for potentially threatening events, but among their most valuable tools is the monitoring of chatter. Intelligence agencies scanning e-mails, phone calls, and online chat rooms can follow the frequency that certain signals occur. If a journalist were to fire off an e-mail that included the words
al-Quaeda
and
bomb
for example, it would be picked up by an automated system that filters for suspicious key words. Having said that, it would not likely make it to the desk of an analyst, since the systems also register e-mail accounts and IP addresses and would hopefully flag the chatter with
journalist
.

During testimony on the September 2001 attacks on the United States, the former CIA director George Tenet said that the “system was blinking red” in the months leading up to 9/11. Similarly, although it was an accidental event, the day that the Chernobyl reactor melted down in 1986 there was a significant spike in message traffic in the former Soviet Union. Knowing what sorts of key words to look for and who the usual suspects are, as well as understanding how they communicate with each other can provide valuable intelligence to help predict rare but important events.

As Don and I considered it, we asked ourselves what a global system to monitor the viral equivalent of such chatter would look like. How could we monitor the many thousands of interactions that occur between humans and animals in order to detect the chatter events—in our case the jumping of novel viruses to humans—that would signal a looming plague?

Clearly, a system that depended on communities like the primatologists, whose primary focus was studying animal behavior and ecology, would not be sufficient. An ideal system would monitor global viral diversity in humans and animal populations and detect when agents jumped from animals to humans. While theoretically possible, such a system defied resources and technology at the time.

As we’ll discuss in greater detail in chapter 10, the current laboratory methods for accurate and comprehensive surveys of the diversity of viruses in people and animals, while improving all the time, are not yet at the point of being deployed globally. Also, the simple logistics of monitoring everyone would be impossible. To begin, we’d need a much more focused system—a system focused on a small set of
sentinels
, key populations that would allow us to monitor viral chatter with the resources we currently have.

*   *   *

I remember vividly the first time I thought about the role of hunting in the transmission of infectious agents. While a graduate student at Harvard, I spent my first two years focused on the study of wild ape populations. Among the pleasures of being a graduate student in the Department of Biological Anthropology was being able to interact with one of the leading professors, Irv DeVore. Irv, a leading teacher and thinker in primatology and human evolution, has a striking head of white hair and a Vandyke beard to match. The son of a Texan Baptist minister, he taught human evolution with the fervor of an evangelist and is beloved among the scores of prominent scientists who benefitted from his tutelage.

Dr. Irv DeVore during pioneering work to study wild baboons in Kenya. (
Nancy DeVore
)

From 1993 through 1995 I worked for Irv as a teaching fellow for the class he co-taught at the time with the Harvard psychologist Marc Hauser. The course, Human Behavioral Biology, was referred to as “Sex” by the Harvard undergraduates because of the focus on human reproduction. During those years, I had the opportunity to meet with Irv in his office on the top floor of the Peabody Museum and on occasion at the wonderful evolution-soaked beer hours that proliferated at faculty homes.

On one particularly memorable afternoon, I remember speaking to Irv in his wood-paneled office in the Peabody. During our freewheeling conversation, the topic reverted to my growing obsession at the time—microbes. It was then that Irv told me a story that would help put me on the research track I’ve taken for the last fifteen years.

During one of his summers spent on Martha’s Vineyard, Irv had come across a dead rabbit while driving home. Assuming it was a healthy animal that had been killed by a car and being a lifelong hunter who had worked with indigenous hunters throughout the world, Irv did what seemed natural for him. He picked up the rabbit and brought it home, where he subsequently dressed and cooked it for supper.

Within a few days Irv was very ill. He experienced fever, diminished appetite, and severe exhaustion. His lymph nodes enlarged. Fortunately, he went to an emergency room immediately, because as it turned out he’d acquired tularemia, a potentially fatal bacteria that often infects wild rabbits and other rodents. Death occurs in less than 1 percent of people with prompt treatment, but had he not been treated quickly, he may very well have died a painful death from multiple organ failure.

Irv likely acquired tularemia when skinning the infected rabbit. A common route of entry for this bug occurs during butchering, when the bacteria can be inhaled into the lungs. By the time Irv finished his story, my mind was racing with the possibilities. One of Irv’s earlier works was a book called
Man the Hunter
, and he’d spent many years living with hunter-gatherer populations in Africa, populations that don’t practice farming and live exclusively on wild foods. Our conversation veered to the idea of working with these populations, who no doubt had extraordinarily high rates of exposure to the microbes in the animals around them.

*   *   *

In 1998, a few years after my conversation with Irv, I wrote about the role of hunting in disease transmission. In the article, I proposed that hunters could act as sentinels—and if we studied them over time we could get a sense of what, how, and when microbes were jumping into humans. During my conversations with Don Burke a few years later, this became a common point of discussion for us as we explored the concept of viral chatter. How might hunters lead us to the critical microbes making that fateful jump into the human species?

When Don recruited me to join his growing program at Johns Hopkins, he had already established a close collaboration with a Cameroonian scientist examining retroviruses, like HIV, in the region of central Africa where they originally emerged. I would spend many years working with Don and the Cameroonian colleague, Colonel Mpoudi Ngole. During those years, we would put the foundation in place for the first real system attempting to catch novel pandemics before they emerge.

One of the first people I met when I arrived in central Africa was the aforementioned Colonel Mpoudi (pronounced m-POODY), a large, imposing, mustachioed man who so consistently wore a uniform that I wondered at times if he slept in it. The Colonel, as I refer to him to this day, is a quiet but incredibly productive physician and scientist. He is known by many of the people in Cameroon as Colonel SIDA (SIDA is the French acronym for AIDS) for his years of relentless work to stem the tide of the AIDS pandemic in central Africa. The Colonel has a subtle yet commanding presence, and he’s used to getting his way. During my first years in Cameroon, we did battle from time to time, fighting over the best way to use scarce resources. Yet I always respected him as an effective and caring leader who knew how to negotiate better than anyone I’ve ever met, and even more importantly knew how to get things done. Over time, he came to be an important mentor and dear friend.

Colonel Mpoudi Ngole.
(
Nathan Wolfe
)

Among the subjects that Don and the Colonel had thought carefully about was bushmeat, and it would be a central subject for the work we’d do in central Africa.
Bushmeat
is another word for wild game, although historically the term tends to refer to wild game in tropical locations. In reality, when my friends hunt and eat venison in their yearly New England ritual, they’re eating bushmeat. And when I visit my favorite seafood place in San Francisco—Swan Oyster Bar—the living sea urchin they carve open and serve me in the shell is also bushmeat. Yet as we learned in chapter 2, from the perspective of microbes not all bushmeat is created equal.

*   *   *

When we started our work in Cameroon, the overriding objective was to understand why HIV in central Africa was so diverse compared to the fatal but genetically bland and homogenous cosmopolitan versions of the virus that hit most of the world. The idea was to sample HIV from people throughout rural regions and hopefully explain why so many different genetic variants of the virus existed in this part of the world. All of the evidence pointed toward this region as the place where HIV began, but why did it remain so diverse twenty years after the pandemic had exploded?