New bird flu strain creates fear and surveillance
An emerging bird flu that is mysterious and deadly is haunting China. With four fresh H7N9 cases reported in Jiangsu Province and no indication as to how three Chinese adults caught the little-noted avian flu virus that killed two of them in March, the global medical community is hoping the new flu will calm down until China’s health system can determine how it spread.
“I can tell you this thing is real and definitely has the markings of being a killer,” says Jason Tetro, coordinator of the Emerging Pathogens Research Centre in Ottawa, which on Monday examined gene sequences from three of China’s H7N9 cases.
“I don’t wish to cause panic,” Tetro said in an interview, noting that if the subtype were proven to have emerged from a small farm, he wouldn’t be much alarmed. Infecting a big poultry reservoir, on the other hand, might well enable H7N9 to access Asia’s wild bird population. The upstart subtype could then become as menacing as H5N1, which since 2005 has officially taken 371 lives in 622 cases, mostly in China, Southeast Asia and Egypt, according to the World Health Organization. The additional Chinese cases have convinced Tetro that “close contact with birds” has been involved. “And I think the CAFOs [industrial chicken farms] have definitely contributed to the evolution of this virus,” he says.
Already, “the internal genes of H7N9 are very close to those of H5N1,” says Mike Coston, a widely read American flu blogger, in an interview. (Coston’s Avian Flu Diary noted on March 14 that a paper in the U.S. Centers for Disease Control’s Emerging Infectious Disease Journal had identified the Shanghai area as one well suited to breed a new genetic subtype of influenza.)
In a development unwelcome to Chinese authorities, many Chinese microbloggers are associating the H7N9 deaths with the still-unexplained swine carcasses that last month floated down the Huangpu River, which provides Shanghai’s drinking water. (Local health officials announced on Monday that the dead pigs contained no bird flu virus.)
Memories of China’s repression of news during its tumultuous 2002-03 SARS outbreak could fuel panic and unrest at home and suspicion in the West. A Tuesday editorial in China Daily reminded readers that China’s minister of health and the mayor of Beijing were dismissed 10 years ago “for trying to cover up the disease.” And there are signs that authorities this time, too, have been less than forthcoming; the Jiangsu Province Health Department announced the four new H7N9 cases only after a microblogger whose Weibo profile says he is a hospital administrator posted a shot of what looked like a patient’s diagnosis on Tuesday.
This might explain why FluTrackers, a U.S. website that hosts a global volunteer disease-surveillance network, has been suffering renewed denial-of-service attacks that it says are originating in China. The Florida-based site first noted server overloads in April 2011 and was told by its server provider in mid-December 2012 that page views from China were running at an “astonishing” level that closed the month at almost 10 million, said Sharon Sanders, FluTrackers’ president and editor-in-chief, in a series of e-mail exchanges.
After FluTrackers banned Chinese IP addresses that were sending thousands of requests, traffic slowed by more than two-thirds, only to rebound in March to almost 6.7 million page views from China. “When the site goes down, it is extremely inconvenient,” wrote Sanders, but a backup site that uses “multiple social media venues” makes it “really impossible to take us down.”
Why would Chinese authorities care about FluTrackers? For one thing, the nonprofit website is watching China. An item Sanders posted on March 7 seems to have constituted the first overseas mention of the Shanghai H7N9 cases. While journalists in China and Hong Kong dig for stories there, FluTrackers has about 50 regular posters and several hundred intermittent volunteers tracking and documenting threats to public health — particularly emerging diseases — around the world. The site, which Sanders founded with some fellow H5N1 watchers in 2006, publishes daily in English, French, Dutch and Italian, biweekly in Spanish, and occasionally in German, operating 24 hours a day, seven days a week. “No one is paid. Everyone is a volunteer,” she wrote. “We do not accept any advertisements and we do not sell anything.”
On Monday, for instance, Chinese authorities and the World Health Organization took heart that no signs of human-to-human H7N9 transmission had surfaced. That evening, FluTrackers posted a machine-translation of a bylined report that had just been posted at wenweipo.com, a Hong Kong newspaper’s website. The story tells of unusual pneumonia cases afflicting four men and a woman in a Shanghai hospital — all aged 60 to 70 and with no history of interpersonal contact. Speaking anonymously, a doctor is quoted as saying the hospital annually copes with about three cases of “unexplained severe pneumonia,” but that all five of the special cases are being labeled as such, though they have not been isolated. A second report indicated that three of them may have died.
So does H7N9 have pandemic potential? “I’d say that the majority of virus comes from H9N2, which many researchers have suspected could be the next pandemic. The makeup of this virus is similar to one that researchers have suspected could be the next pandemic. However it’s not quite there yet,” says Tetro. “We know that it is not spreading from human to human, but we know that in some cases, direct or close contact with poultry or birds is a route of infection.”
On the other hand, he finds the revelation of fresh cases in Jiangsu comforting: “This is actually an official statement. I’m more optimistic that we’re going to have a better epidemiological understanding of what is happening in China.”
“Many epidemics break out, spread and burn themselves out all the time in China. We just never hear about them,” says Coston. “But I think it’s already in the birds.”
We’ll all be watching.
PHOTO: French doctor Alix Greder-Belan shows a protective face mask to be used by hospital staff in case of a bird flu pandemic at the Mignot Hospital in Versailles October 10, 2005. REUTERS/Franck Prevel