But those numbers may balloon as H7N9 makes its way beyond the mainland Saturday: "Hunan cases come a day after the eastern province of Fujian reported its first case and during the same week that a man in Taiwan become the first case of the flu outside mainland China," Reuters reports. Here's what the trail of those three main regions — Fujian, Jiangxi, and Hunan — looks like, with millions of human beings in between:
Jiangxi, the province in the middle, reported its first suspected case on Thursday, Xinhua reported. Regardless of where the cases started, the disease has been spotted in both directions now. And on the horizon looms a gigantic mainland exodus. "Around 4.2 million people are expected to cross to Hong Kong from Shenzhen between April 27 and May 1 to celebrate the Labor Day holiday," reports Jake Maxwell Watts at Quartz, our sister publication. Hong Kong reported its first suspected case this month which caused concern, but that turned out to be a false alarm. If you thought the first case in Taiwan was bad, 4.2 million people coming in from mainland is a lot of people, and it could mean a ripe opportunity for the disease to spread.
Meanwhile, in the labs, precious little is known about the strain. There's the good news: "Chinese scientists confirmed on Thursday that chickens had transmitted the flu to humans," reported Reuters. But that still does not explain the cases where people who didn't come in contact with poultry still caught the disease. At Foreign Policy, Laurie Garrett points to trouble:
There is a missing link. For the new virus to have acquired these key mutations, it must be infecting a mammalian species of some kind, besides human beings. It had to have picked up those mutations inside a mammalian host. But to date no infected pigs or other mammals have been found, according to the Chinese CDC.
This is a mystery. And here is another: Nearly all known bird-to-human flu jumps have occurred in rural settings, unfolding on and around farms. But not this H7N9: This may well be the first truly urban influenza in history. No infected rural flocks or farmers have been found in China. This outbreak started in one of the most modern, densely populated metropolises in the world: Shanghai.
That (scary stuff) said, a visiting team from the World Health Organization insists there exists no hard evidence sustained human-to-human transmission, even if they did call it "one of the most lethal" flu viruses ever. "One of the things we need to be concerned about is this might gain the capability of going human-to-human which up to this point has not happened and is somewhat encouraging news," Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases (NIAID) and a top U.S. virologist, told the Agence France-Presse in an interview. "But we still need to be very prepared for the eventuality of that happening."
Correction: There were reports of a H7N9 case in Hong Kong earlier this month. A seven-year-old girl showed the signs, was put in quarantine, and later tested negative. We've update the article to reflect that.
This article is from the archive of our partner The Wire.