HONG KONG— Since the first H7N9 fatality was identified in Shanghai in early March, the latest variant of the avian flu virus has spread across three Chinese provinces - 700 kilometers apart. Some 24 people are now infected and seven have died.
China is stepping up surveillance measures after authorities closed Shanghai poultry markets last week and culled stocks after the virus was detected in local pigeons. In Taiwan, supplies of anti-viral medicines are being made available for subsidized public sale.
There are still questions about how susceptible H7N9 is to antiviral drugs like Tamiflu. Shanghai Municipal Center for Disease Control reported Monday that a 4-year-old boy has made a full recovery, offering hope H7N9 can be treated successfully.
Professor Malik Peiris is scientific director of the Pasteur Research Center at Hong Kong University. He is also the first scientist to isolate the SARS virus that killed more than 700 people in 2002 and 2003. He cautions against reading too much into the mortality rate of the flu virus.
“I think you have to be cautious about interpreting mortality rates because, usually, only the most severe cases are investigated. There could be milder cases that go unrecognized. So, on the one hand, this would make the mortality and the severity less. But of course, on the other hand, it would mean there is more transmission occurring in humans too,” Peiris said.
Inspecting a poultry wholesale market Monday, Hong Kong health secretary Ko Wing-man said that by the end of this week live poultry imports will only be sold after 30 in every 1,000 birds are tested for H7N9. Tests will be expedited and results returned within four hours.
But while governments are implementing response plans across Asia, Peiris warns that to develop vaccines and break the infection cycle, it is imperative the source of the outbreak be identified.
“Learning from H5N1, it is quite an unpredictable virus in that there are hundreds of people working closely with poultry who do not seem to get infected," he said. "But there is the one person who may have quite a tenuous contact who [does] … So, I think what is crucial is to go upstream, along the poultry marketing chain, ideally to the farms, and identify which species is the main source.”
Hong Kong is still commemorating the 10th anniversary of SARS, which infected thousands as it spread from China across three continents. Many here are fearful the Chinese government coverup that contributed to the spread of SARS could be repeated with H7N9.
Thomas Abraham, director of the public health media program at Hong Kong University and author of "21st Century Plague; the Story of SARS," believes this is unlikely. Beijing has learned valuable lessons since SARS, and social media challenge governments’ ability to control information.
“One of the early [H7N9] cases in Shanghai, even though the hospital said nothing, the patient’s admission slip was photographed and put up on Weibo (China’s Twitter)," he said. "This kind of information flow is a dam that is unstoppable. It is an entirely new environment the Chinese authorities are working in.”
Although World Health Organization officials have said there is no need for panic, Laurie Garrett, senior fellow for global health at the Council on Foreign Relations, warns there could be trying times ahead if the H7N9 death toll continues to rise.
“What 2009 taught us with the swine flu [pandemic] is that global solidarity can break down very fast. Countries start closing airports and quarantining travelers; they start hoarding drugs and vaccines. It is not a pretty pictur,” Garrett said.
Though public sentiment remains fragile, some reassurance was offered by Hong Kong University last week. Researchers there announced they will revisit a 2009 study in order to confirm that surgical masks, seen widely on the streets of Hong Kong in peak influenza season, are indeed 70 percent effective in preventing the spread of flu viruses.