The SARS outbreak taught scientists new ways to respond to global health threats - photo by Martin Dee
UBC Reports | Vol. 53 | No. 1 | Jan. 4, 2007
A Scientific System that Shuts Down New Diseases Fast
By Prof. B. Brett Finlay
UBC Peter Wall Distinguished Professor, Michael Smith Laboratories
and Prof. Robert. C. Brunham
Provincial Executive Director, B.C. Centre for Disease Control (CDC) and Director, UBC CDC
Imagine one of our worst fears comes true: a deadly new disease emerges -- in Asia, rural Russia, or South America, for example. Local populations begin to rapidly succumb, and individual cases pop up in North America and Europe. Now consider this: a global network of scientists spring into action -- the pathogen is isolated and the genome sequenced within days. Epidemiologists use highly developed models to quickly isolate, quarantine and treat cases and shut down human transmission. And within weeks, work is underway on a vaccine. This is the vision driving UBC infectious disease experts Brett Finlay and Robert Brunham.
Predicting the next big outbreak of an infectious disease is nearly impossible. For example, SARS came out of nowhere. Although bird flu is often discussed as a possible pandemic, it is also possible that the next big thing will be some new variant of a virus or pathogenic microbe that is new to us. Thus to us, the next big thing is to build capacity to fight an unknown foe by learning from past experience.
SARS was a major wake-up call to the world. It was unforeseen and unknown to medical science. It spread around the world in an extremely rapid fashion, and caused great anxiety worldwide. Although the number of people who actually were infected with the SARS virus was less than 10,000, and the number of people who died less than a thousand, worldwide SARS is estimated to have had a global cost of $100 billion, mainly in Asia and Canada. To put this in perspective, at least 54 million people die every year, and one-third of these die of infectious diseases; and the1918 Spanish flu killed an estimated 20-40 million people, which is more than all those who died in World War I.
However, SARS taught us much about how new diseases emerge and how to respond to these threats based on coordinated ways that use cutting edge science to mobilize solutions. SARS galvanized the global public health community into sharing information in an unprecedented manner. Scientists rapidly isolated and sequenced the SARS virus, and found it belonged to the coronovirus family, which usually only causes mild upper respiratory infections. In a global race to sequence it, its entire genome was unraveled in a mere eight days by at least three separate groups. Put into perspective, it was in the 1930s when scientists finally isolated the cause of the 1918 flu pandemic and it wasn’t until 2005 that its genome was deciphered in a tour de force of paleogenomics. Knowing the sequence of an emerging pathogen leads to attempts to combat it. These attempts include rapid science to develop prototype vaccines and new ways to scientifically respond to unknown threats (Finlay, B.B., See, R.H. and Brunham, R.C. 2004. Rapid response research to emerging infectious diseases: lessons from SARS. Nature Rev Microbiol 2:10-16). Moreover, the SARS experience also showed how we can rapidly determine how pathogens spread (small droplets and close contact), and use epidemiologic science to guide public health measures such as isolation or quarantine to limit further transmission. Interestingly it was these public health approaches that broke the chain of transmission of the SARS virus and drove it back into nature.
Our capacity to do major science on infectious threats continues to accelerate. We can now rapidly identify and sequence pathogens potentially within hours of first isolation. We can employ sophisticated methods to develop vaccines and potential treatments. We can use mathematical modeling to predict global spread patterns and quantify the impact of treatment and quarantine strategies. Although it may appear that the sky continues to fall because of the prediction of new pandemics, we now have many new ways to counter these threats. In our opinion, the next big thing in the battle against emerging diseases is a coordinated global scientific attack on such problems. As in war, one must first understand the enemy, and then use that knowledge to try and overcome the threat. We are now entering an era where we can begin to understand and neutralize these threats, instead of standing by and hoping for the best. This is the next big thing.