Before the SARS epidemic hit China, the country had neither a command system for public health emergencies nor clear regulations on which agencies are responsible for rating these events and taking action. The government was not compelled by any law or regulation to publicize information, inform the public, mobilize resources or take quarantine measures in cases of a health emergency.

China's national county-based disease control and prevention network took shape in the 1950s with trained professionals graduating from public health programs. Despite the remarkable achievements this monitoring system made in controlling epidemics, its efficiency was severely undermined by the shortage of government input at the beginning of this century.

Between the end of 2002 and early 2003, fear about being infected with SARS circulated quickly among people in Guangdong, where the SARS virus originated, and the lack of official figures of actual cases caused an information vacuum that was filled by sensational rumors. Plagued by anxiety, residents started to stock up on white vinegar and Chinese herbal medicine that were believed to be effective against the virus. This shopping craze caused price spikes and speculation on these erstwhile daily necessities.

Shortly after arriving in Guangdong as the head of an epidemic research team, Zeng suggested to the Central Government that the most urgent task was not to tell the public what the causal agent was, but the timely update of actual cases. Zeng found that many hospitals covered up confirmed cases as staff members were afraid of being held responsible for new infections and unreported cases severely impeded accurate evaluation of the outbreak.

After returning to Beijing, Zeng investigated the situation in major hospitals. He learned that many patients treated for other diseases and medical workers were picking up the SARS virus there. On April 22, 2003 Zeng visited Peking University People's Hospital, which allegedly had the most severe cases of cross infection among local hospitals. He warned that new cases would skyrocket without effective quarantine measures, and suggested all SARS patients in Beijing's hospitals be immediately transferred to a designated suburban hospital.

The Beijing Municipal Government took Zeng's advice and quarantined the hospital the very next day. In addition, a comprehensive facility with state-of-the-art equipment was assembled within seven days by 7,000 workers working around the clock in Beijing's northern suburb of Xiaotangshan Township, Changping District.

Zeng said that during the following days, his opinions received unprecedented attention from government decision makers. "We disease control experts were consulted before almost every decision was made," he said, adding that was widely different from earlier stages of the epidemic when officials focused on finding a clinical treatment and developing a vaccine.

According to Zeng, as early as January 2003 he found that transmission of SARS only occurred after people had close contact with patients showing symptoms and suggested quarantine measures. However, medical resources were concentrating on identifying the pathogen, and voices from disease control experts were ignored until it was too late.

Liu Qi, then Secretary of the Beijing Municipal Committee of the Communist Party of China (CPC), reportedly told Zeng that Beijing would have 100 fewer SARS patients if he could have heard Zeng's suggestions 10 days earlier.

Immediately after being appointed as member of an expert panel on SARS control directly under the State Council, China's cabinet, in late April, Zeng asked the Beijing Health Bureau to establish an outbreak information system to collect the actual number of cases from each medical facility.

"We had the true number of total cases in Guangdong but we didn't have that figure in Beijing. In the past, some officials thought we needed to keep this information a secret. However, how could we effectively respond to this epidemic without knowing the correct figures?" he said.

Zeng gave a 40-minute lecture to China's top leadership, including then President Hu Jintao, on April 28, 2003. He said that he remembered seeing Hu nodding his head when hearing about publicizing the status of the SARS outbreak.

Before Zeng's lecture, President Hu, also General Secretary of the Communist Party of China (CPC) Central Committee, warned all levels of government against laxity in reporting SARS cases at a meeting of the Standing Committee of the Political Bureau of the CPC Central Committee.

On April 20, 2003 Beijing Mayor Meng Xuenong and Minister of Health Zhang Wenkang were removed from their positions, and a national command center for SARS prevention and treatment was set up. On the same day, the Ministry of Health mandated daily reports from all provinces on new cases and prevention measures.

On April 23, the central treasury set up a 2-billion-yuan ($322 million) fund for controlling SARS.

On May 9, the State Council released Regulations on the Handling of Public Health Emergencies. Its drafting and adoption were completed within a record-breaking 15 days.

"As the country's first ever regulations on public health emergency handling, they define duties and responsibilities of various government departments. They serve as the first legal instrument for building an emergency response mechanism and a complete legal framework for handling public health emergencies in the future, as well as provide guidance for local governments of all levels for building their own emergency response programs," said Song Ruilin, who headed the drafting team of the regulations.

Zeng said that instead of any advanced technology, containing SARS only required timely release of the outbreak status information, quarantine measures to cut off further infection and special protection for high-risk groups. "The severity of the outbreak was due to China's weak public health monitoring system with too many loose links," he noted.

"It became clear to us that public health services and control of major epidemics concern not only health authorities but the whole society. The government should take the primary responsibility," said Wang Longde, then Vice Minister of Health.