“It’s a delicacy, for special occasions,” said Sambourou Diop, a Gabonese national living in the region, who sampled bush meat in his West African homeland but has not eaten it here.
For the nation’s disease detectives, though, bloody bags of wild meat could mean big trouble. They’re worried about exotic viruses causing a deadly outbreak — or, in the worst case, an AIDS-like pandemic.
That’s why the Centers for Disease Control and Prevention launched an expanded effort to test confiscated bush meat for potentially dangerous viruses after a two-year pilot study.
After all, the virus that causes AIDS jumped from chimpanzees to humans at least three times early in the 20th century, sparking a worldwide crisis that has killed at least 25 million people. And in 2003, an unknown virus leapt from bats to civet cats to people in southwest China. The virus then spread to 29 countries and killed at least 774 people. It was dubbed SARS, for severe acute respiratory syndrome.
Infectious-disease experts are convinced those two viruses moved into humans via the butchering, handling and eating of infected meat. And they’re all but certain that other scary viruses lurk in the world’s wildlife.
“We’re in the dark with risks,” said Kristine Smith of the nonprofit EcoHealth Alliance. “We know there are risks out there, but we aren’t able to quantify them.”
Beginning in 2008, Smith, a wildlife health expert, aided the CDC on a pilot project to test bush meat confiscated at Dulles International Airport, John F. Kennedy International Airport in New York, and airports in Houston and Atlanta.
The effort netted heads, arms and other pieces of two chimpanzees (members of an endangered species), seven monkeys and 35 rodents, mostly giant cane rats. It is illegal to bring any of those animals into the United States.
Also found were three exotic viruses, although they do not appear dangerous to humans. Two of the viruses are in the same broad family as the viruses that cause herpes in humans. The third virus, simian foamy virus, was found in seven monkeys and one of the chimpanzees. That virus has been on CDC’s radar for a few years because, like HIV, it is a retrovirus. It insinuates itself into the host’s DNA, where it persists, perhaps for a lifetime.
To date, there are no signs that simian foamy virus makes people sick, the CDC’s William Switzer said. But the agency has estimated there are 130 people infected with it worldwide. The agency is tracking only about 15 of those cases. Most are laboratory or zoo workers who handled monkeys and apes, or blood or tissue from the primates.
“We’re looking at whether these viruses are transmissible to close contacts, spouses, children, and so on,” Switzer said.
With modest funding — $59,740 — the CDC is expanding virus testing nationwide to bush meat confiscated at 18 of the agency’s 20 quarantine stations, typically located at airports. The CDC official who heads up the effort, Nina Marano, said the program’s funding is uncertain beyond this year.
“So much of this is smuggled in, we can’t find it, can’t track it,” Marano said. “We’ll never get a complete picture.”
Some experts are worried that efforts to stem the bush meat trade are too meager. “We could do a much, much better job than we have done previously,” said George Amato of the American Museum of Natural History in New York. For the CDC pilot project, whose results were published in the journal PLoS One this month, Amato examined the DNA from confiscated bush meat to identify what species the parts came from.
“This is the kind of study that, if Michael Crichton were still alive, he would turn it into a novel,” Amato said. “This is how a new pathogen could emerge.”
At the CDC’s Dulles station, Miguel Ocana, a physician, is the only employee. Last summer, Customs and Border Protection agents passed him monkey parts that they found in a well-taped box. (Border agents find many bizarre items at Dulles.) Ocana extracted a bit of tissue and sent it off for testing.
“African rodents are very common,” Ocana said of some packages that arrive in his office. “Sometimes you have to put the pieces together like a puzzle to find out what you’re dealing with.”
Virus hunter W. Ian Lipkin would also like to know what he’s dealing with. Many of the CDC’s bush meat samples land in his laboratory at Columbia University. There, Lipkin’s team tests the meat for known — and, with advanced techniques, unknown — viruses. His search for previously unseen viruses in the bush meat is just beginning, and the animal parts keep piling up.
“I like to call this medical intelligence,” said Lipkin, who in 1999 identified deadly West Nile virus in the brains of its first U.S. victims. “We need to know what’s circulating.”