As more and more cases of bird flu crop up in eastern China, the reassuring voices of the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) are urging Chinese citizens—and international travelers—to remain calm but vigilant: There is no need for full-on alarm unless or until solid evidence emerges that someone can catch the virus from other people, as well as from chickens.
Human-to-human transmission, in scientific parlance, is the threshold at which the outbreak of the H7N9 “bird flu” in China might transition from an alarming episode to the start of a potential epidemic. David Quammen, author of the recent book Spillover: Animal Infections and the Next Human Pandemic, echoed this sentiment in a lucid opinion piece for National Geographic online, entitled “Too Early to Panic Over Bird Flu.”
Now, with the official casualty toll at 62 confirmed human cases and 14 deaths in China, health authorities are closely scrutinizing a husband and wife in Shanghai—both of whom are infected with the virus—to determine whether he caught the virus from her, or whether they were both sickened by the same source.
Separately, and worrisome for a different reason, is that the virus is no longer confined to the geographic region around Shanghai: Over the weekend, new cases were confirmed in Beijing and in northern China’s Henan province, including a 7-year-old girl who’s being treated in the intensive-care unit of a Beijing hospital. This news most likely means that infections in birds, as carriers of the H7N9 virus, range much wider than previously thought—far up and down China’s east coast.
China’s health authorities have largely won praise for the alacrity and relative openness with which they’ve handled the outbreak thus far. Now they’re welcoming international assistance, as the challenges appear to be escalating: On Wednesday experts from the WHO, CDC, the University of Hong Kong, and the European Centre for Disease Prevention and Control in Stockholm are due to arrive in China. In the meantime, Beijing has joined Shanghai and Nanjing in temporarily banning live poultry trading, which is still suspected to be the major source of infections.