David Heymann
Head and Senior Fellow, Centre on Global Health Security

This week marks the 10th anniversary of the beginning of the SARS outbreak, with the first known case of a strange type of pneumonia being recorded in the Guangdong Province of China on 16 November 2002. The elimination of SARS from human populations is one of the most significant international public health victories in recent times, and its legacy is evident.

The case in Guangdong Province, and sporadic others that were later discovered to have occurred around the same time in the same location, did not come to light until 10 February 2003, following a sharp rise in the number of infections. About a month later, after mounting reports of spread among hospital staff in Hong Kong and Vietnam, it became apparent that this constituted a new contagious disease of international concern. This prompted the World Health Organization (WHO) to sound the alarm. Within days it was clear the disease was spreading along major airline routes and it went on to infect nearly 8,500 people in 30 countries and kill 916. 

It was rapidly contained within less than four months of the initial alert, as a result of an unprecedented level of international cooperation designed to prevent it from becoming established in people, as HIV/AIDS had done during the 20th century. A decade after its abrupt and deadly arrival, the lessons of SARS are clear.

The power of global collaboration         

Firstly, the SARS experience clearly illustrated the value of and success that can be achieved through global cooperation. It was the first emerging disease outbreak to be the focus of a major global containment effort, and provided a valuable template for responding to similar threats in the future. This is a major legacy of SARS.

It emerged at a time when the state of technology could allow the response to be immediately adapted, in real time, which had not been possible at the time of the detection of, for instance, HIV in 1981, or the 1918 'Spanish flu' pandemic. WHO took advantage of this and within a week of issuing the initial alert, established three virtual networks of the world’s leading laboratory scientists, public health experts and disease investigators, to speed up discovery of the cause of the disease and development of a reliable diagnostic test, pool knowledge on symptoms of the disease and how to treat it, and track how and where it was spreading and how well control measures were working. The networks were linked by a secure website and daily video and teleconferences coordinated at WHO’s Geneva headquarters. Based on the evidence coming in, recommendations were updated and disseminated through multiple channels, allowing those on the ground to adapt immediately.

The culprit virus was identified in record time - one month after the establishment of the virtual laboratory network. This, together with other actions resulting from findings of the virtual networks, such as travel restrictions and other isolation measures, were key to interrupting transmission and shutting down the outbreak. The template created for SARS was later applied to the 2009 H1N1 flu pandemic, and will continue to enable nations to respond to such emergencies in a more evidence-based and effective way.

Reporting now expected and respected

Secondly, the SARS experience changed the norm regarding national transparency in sharing information on contagious disease outbreaks. Prompt international reporting and response is now expected and respected in a way it had not been previously. The epidemic dramatically illustrated both the human and economic toll that international outbreaks can take in an increasingly interdependent world. There is now more recognition that early reporting averts death and suffering at home and abroad, minimizes domestic and international economic damage, and protects credibility in the international community. 

A World Health Assembly resolution passed in the midst of the SARS outbreak acknowledged that strengthening outbreak alert and response was critical to defending global health security against infectious disease threats. Another resolution passed at the World Health Assembly at the same gathering gave WHO more power to respond to outbreaks by allowing the agency to react to information provided by sources other than national governments. This helped pave the way for the 2005 revision of the International Health Regulations, which expanded the disease scope for which reporting to the international community is mandatory and required countries to strengthen their capacity to better detect and respond to disease outbreaks in order to slow or prevent their international spread. 

Thirdly, SARS provided a valuable lesson in the importance of naming diseases carefully, so as to avoid stigmatizing countries or industries. WHO named the disease after its symptoms, early in the outbreak, successfully averting the stigma that has historically affected countries and industries once they have been associated with diseases through the naming, such as in bird flu and Hong Kong flu. 

SARS will not be the last disease to threaten the world. For all the success the international community achieved in combatting it, and the legacy it left in raising infectious disease risk up the political agenda and shaping the strategy for preparing for and responding to future outbreaks, it was a reminder that luck also plays a role in outbreaks. Had SARS spread to some of the more vulnerable corners of Africa, where health systems and outbreak alert and response infrastructure is weak, the story could have been very different. 

David led the WHO response to SARS, as Executive Director of the WHO Communicable Diseases Cluster.