美国国家公共电台 NPR A Taste For Pork Helped A Deadly Virus Jump To Humans（在线收听）

SCOTT SIMON, HOST:

When you talk to disease experts about what might alarm them, it's not Ebola or Zika. It's Nipah. It's as deadly as Ebola but attacks the brain, and it has the potential to spread by mere cough. As NPR's Michaeleen Doucleff reports, Nipah originated in Malaysia - the unintended consequence of that country's efforts to lift itself from poverty. A warning, this story includes some graphic descriptions.

MICHAELEEN DOUCLEFF, BYLINE: This story begins in a small farming town called, Nipah. It's where the virus gets its name. It's about an hour drive south of Malaysia's capital, Kuala Lumpur.

So I'm riding with Thomas Wong who was a pig farmer here 20 years ago.

THOMAS WONG: (Foreign Language Spoken).

DOUCLEFF: He says everyone in Nipah was a pig farmer because Nipah was at the center of Asia's booming pork industry. The region was going through a huge economic surge. Families now had enough money to buy pork for lunch and dinner. So pig farmers were getting rich.

How many pigs were in this area?

WONG: About half a million.

DOUCLEFF: Half a million pigs - wow.

WONG: Yes. Very densely populated.

DOUCLEFF: Very densely populated. And they're all gone now?

WONG: Oh, no. All buried.

DOUCLEFF: All buried, all underground because back in 1998 something went terribly wrong here. Wong pulls up to an abandoned farm.

So maybe you can take us through what happened? So the disease came to this farm here?

WONG: Yeah. The pigs...

DOUCLEFF: He says, first, baby pigs started getting sick. They'd get a cough, couldn't walk. Then they'd died. There were so many dead piglets that their bodies piled up around the town, and the town smelled like death.

WONG: Oh, the smell - dead like dead rats.

DOUCLEFF: Then the situation got worse. People started dying.

WONG: Every day we'd see the newspaper that people dying.

DOUCLEFF: Did you lose any family or friends?

WONG: Friends, yes - lots of friends.

DOUCLEFF: The disease struck lightning fast. Dr. C. T. Tan is a neurologist who took care of patients from Nipah. He said farmers were healthy one day, and then their brain swelled up. They couldn't walk or talk.

TAN CHONG TIN: They'd become comatose. And some of them become paralyzed.

DOUCLEFF: And then...

TAN: After two, three days, they'd die.

DOUCLEFF: There was nothing Tan could do - no cure, no treatment.

TAN: We thought it was some unusual infection, but we didn't know what it was.

DOUCLEFF: And time was running out. Dozens of people had already died in Malaysia, and the disease had spread to Singapore.

WONG: That was frightening.

DOUCLEFF: Yet the Malaysian government told people not to worry - that the disease was coming from mosquitoes, and they were taking care of it by spraying. But one young scientist - he thought the government was wrong.

OK. We're here.

His name is Kaw Bing Chua. I met him at the farm where the outbreak began. He was ordered to test blood samples for the mosquito virus. Those samples kept coming back negative.

KAW BING CHUA: No, no. I know it was something different, and people dying.

DOUCLEFF: Chua thought it might be a new virus, one that the world had never seen before. But to prove it, he had to do something very dangerous. He had to grow the virus in his lab without proper safety measures. Putting himself and his lab at risk so he could study it. He worked late into the night for weeks, said a little prayer before each experiment. Then one Friday evening, he opened up one of his petri dishes, and there it was.

CHUA: I actually saw initially the cell membranes thickening.

DOUCLEFF: You could see the virus actually coming out of the cell.

CHUA: Yes.

DOUCLEFF: And that means you had found what was making them sick.

CHUA: Yes, yes.

DOUCLEFF: What did you feel like?

CHUA: Of course, very fearful.

DOUCLEFF: Very fearful?

CHUA: Yes.

DOUCLEFF: The virus looked ruthless, destroying every human cell he tested. It grew like gang busters. In just a few weeks, he had grown enough to wipe out a whole town. He called his boss over to show him.

CHUA: I said, please come. I want to show you something. When he looked under the microscope...

DOUCLEFF: He didn't believe the results. He told Chua to throw away the experiment. But Chua didn't throw it away. Instead, he took it to the U.S.

CHUA: It was an emergency, actually.

DOUCLEFF: It's an emergency. You had to get it there quickly.

CHUA: Yes.

DOUCLEFF: Did you just carry it with you?

CHUA: Yes. Of course, with special packing.

DOUCLEFF: That's right. Wrapped the samples carefully, put them in his carry-on luggage and boarded a plane to the U.S. Centers for Disease Control and Prevention. The CDC had a special microscope that they could identify exactly what the virus was. Chua will never forget what he saw.

CHUA: The moment I saw the thing, I said, goodness.

DOUCLEFF: You said, goodness?

CHUA: Yes. It's paramyxo.

DOUCLEFF: A paramyxo virus. These viruses come from livestock, not mosquitoes. Scientists think the next pandemic will be caused by a virus like this - highly lethal and the potential to be super contagious.

Chua rushed to a phone, called up officials in Malaysia and told them, stop fighting mosquitoes. It's coming from the pigs. Finally, the Malaysian government listened and did something very drastic.

(SOUNDBITE OF ARCHIVED RECORDING)

TIM LESTER: Malaysia's army moved in for the country's biggest-ever animal culling.

(SOUNDBITE OF PIGS SQUEALING)

LESTER: Almost one million pigs.

(SOUNDBITE OF GUNSHOTS)

DOUCLEFF: That's tape from Journeymen Pictures which reported on the outbreak back in 1999. The results of the culling were dramatic. The outbreak stopped - dead stopped. As Chua is telling me all this, he starts to choke up.

CHUA: No one believed me. Practically begging people to believe - nobody believed me.

DOUCLEFF: It's an amazing story, Dr. Chua. I mean, it's amazing. Your persistence is why this outbreak stopped.

CHUA: (Crying) Let me cool down.

DOUCLEFF: OK.

Chua had saved many lives, but the world was still stuck with a mystery. Why did the pigs get sick? It turned out that the pigs had been getting the disease for years undetected. Dr. Tan, the doctor treating Nipah patients, was studying this.

TAN: In the old days, the pigs were running around, and the family would look after a few pigs.

DOUCLEFF: A few pigs would get sick, but no one was bothered. It just looked like the flu. But in the past few decades, farmers in Asia had changed the way they raised pigs. They were packing more pigs into farms, starting to industrialize them.

TAN: So it also means that when the virus get to the pigs, it can also multiply very quickly.

DOUCLEFF: When you have thousands and thousands of pigs, not 10, there's a seemingly endless supply of new piglets to infect. The pig factory becomes a virus factory. The virus was spreading through coughs from one farm to the next and eventually into farmers.

TAN: The way we grow our food - it changes.

DOUCLEFF: So agricultural intensification was part of the trigger?

TAN: Yes.

DOUCLEFF: And that's something we don't think about. As people get richer, there could be this devastating consequence. In this case, factory farming, which feeds more people, inadvertently created the Nipah outbreak. And you see this around the world. With cows in the U.S., you get new types of MRSA, a flesh-eating bacteria. With chickens in China - a whole slew of bird flu.

TAN: The world is changing so fast.

DOUCLEFF: In Malaysia, pig farms have gotten cleaner, and Nipah has stayed away. But across Asia, there have been more than 16 other outbreaks. And there are signs the virus is evolving, becoming more contagious in people. Michaeleen Doucleff, NPR News.