By Jared Chausow
By Katie Toth
By Elizabeth Flock
By Albert Samaha
By Anna Merlan
By Jon Campbell
By Jon Campbell
By Albert Samaha
Hunting for viruses with Columbia's Simon Anthony
We can only guess what authorities do not find, but one estimate holds that 15,000 pounds of bush meat slip through U.S. customs every month. "I feel there is a lot of stuff that gets through that we don't see at the moment," Anthony says. Globally, the trade is far bigger. One study found that nearly 300 tons of bush meat entered Paris's Charles de Gaulle airport annually.
The scientists analyzed bone marrow and trachea from green monkeys, spinal nerve and eye from baboon, and flesh from mangabey and chimpanzee, all primates. Photographs of the meat show two intact monkey heads, one with the torso still attached, a furry, curled hand and a complete eight-inch arm. In January, the scientists published their findings in the journal PLOS ONE. They announced that the primate meat contained two strains of herpes and four of a species called Simian Foamy Virus. SFV is related to HIV and known to infect humans, but it has not been linked with disease. Still, the presence of these viruses "highlights a potential health risk," they wrote.
Much bush meat is dried or smoked, which can effectively kill pathogens. But deep below top layers kissed by smoke or sun, viruses survive in moisture-rich places like uncooked tissue, bone marrow, eyeballs, and brains. "If you're importing a piece of jerky, I don't think the level of risk is very high," Anthony says. But government photographs of bloody meat in plastic bags show different. Of the chunks examined in the study, the scientists wrote, "most items contained moist inner tissue."
Today, scientists comb the natural world first and later ask if a species they find is pathogenic. For most of modern history, they saw fit only to study agents known to cause disease.
In 1951, Manhattan's Rockefeller University took an early step in that direction, establishing searches, as one historian writes, "aimed in a shotgun approach at 'what may be out there.'" A string of discoveries followed, but within two decades, money ran low, and it abandoned the project. By the 1980s, still a fringe pursuit, pathogen discovery had all but fallen away.
But in the 1990s, techniques from molecular biology were first applied, and the field underwent a renaissance. Suddenly, after decades of slow and faulty methods—growing viruses in lab rats or petri dishes—scientists could detect them with simple tests.
W. Ian Lipkin, director of Anthony's lab at Columbia, was the first person to do this. In 1990, he pioneered this practice by identifying that a virus causes a neurological illness in horses, a process that took three years. In 1999, he discovered that West Nile virus caused the outbreak of deadly encephalitis afflicting New Yorkers. He was invited to be the lab's director in 2002. At the time, it was "a couple of empty floors that needed to be renovated," according to Morse, his colleague then and now. Last year, he acted as scientific adviser on the bio-thriller Contagion. Today, he is investigating whether viruses are behind the unknown causes of chronic fatigue syndrome and autism.
Lipkin built the lab around pathogen discovery, all the while developing new techniques. He and his colleagues invented a new diagnostic method for identifying microbes, MassTag PCR, that instead of detecting single microbes, detects dozens of bacteria and viruses at the same time. He helped develop GreeneChip, a glass slide containing 500,000 genes that is used to test for virtually all known pathogens. His methods were fast and cheap. As he led the charge, the time needed to find a virus shrank from years to days. A team of scientists at his lab can identify an unknown pathogen in hours.
As the field matured, outbreaks were fueled by globalization. A major study published in Nature in 2008 showed an increase of outbreaks in each of the past six decades, nearly quadrupling between the 1940s and the 1990s, when there were almost 100. Infectious diseases are now the second-biggest cause of death worldwide, after heart disease. They account for 17 million deaths per year and kill one in six in developed countries and twice as many in the developing world.
The increasing menace made scientists "sit up and take note," as Anthony puts it. They would soon pick up where the "shotgun approach" left off, but they did not know where to search. A colleague of Anthony's, Peter Daszak, had an idea. In 2008, he published an influential study mapping the places where diseases are most likely to emerge, based on geography and past outbreaks. These "hot spots" are the Amazon and Congo basins and the most densely populated parts of Europe, China, India, and North America. Basically, any place humans and animals are crammed together. New York, the archetypal dense global city, is a bona fide hot spot.
The new model "changed the way people looked at [outbreaks]," Anthony says. It gave rise to "the very concept that this may not be so random." The year after the map was published, literally using it as a guide, several organizations embarked on the global hunt.
As the field's renaissance unfolded, Anthony, the son of a onetime pub owner and an opera singer, graduated from the University of Wales, where he studied zoology. He was offered a job as an elephant keeper at the London Zoo. But the next day, a keeper tripped and was killed when an Asian elephant stepped on him. Because of that, Anthony decided not to go.