At the heart of China’s defenses was the Contagious Disease National Direct Reporting System. Started in 2004, it was designed to prevent a repeat of the SARS epidemic, when slow, patchy reporting, compounded by local leaders’ reluctance to share bad news, delayed the government’s fight.
Using this system, health officers in Beijing could pore over screens showing reports from hospitals or local disease control centers, ready to spot warning signs within a few hours of a doctor diagnosing a troublesome infection, such as cholera or tuberculosis, as well as hard-to-diagnose cases of viral pneumonia.
“Viruses like SARS could emerge anytime, but there’ll never be another SARS incident,” Gao Fu, director of China’s disease control center, said in a speech last year. “That’s thanks to how well our national contagious disease surveillance system works.”
The boasts were not empty.
The system had helped when China and other countries suffered outbreaks of avian influenza. In 2013, authorities filed cases of a potentially deadly H7N9 avian influenza virus, with orders to submit them within two hours of confirmation.
Last November, the country’s Center for Disease Control alerted the public to an outbreak of pneumonic plague in the sparsely populated Inner Mongolia, after only two cases emerged.
Since the outbreak in Wuhan, some doctors have said they were unsure how to report early cases, which did not fit into the standard list of infections. But little-understood infections could still be logged as “pneumonia of unknown etiology” — or unknown cause — when the patients did not respond to the usual treatment.
Year after year, Chinese health authorities warned hospitals to look out for such outliers.
“For many infectious diseases when you don’t know the cause, it can often present itself as pneumonia of unknown etiology,” said Dr. Yang, the retired official. “This was a way of capturing an outbreak while it was embryonic.”