The policy of containment and travel restriction advocated by the WHO ultimately proved successful. By the summer of 2003, the disease had all but run its course. It transpired that, luckily, the virus was maximally infective only when patients were at their most unwell and usually already in hospital. This explained the huge risk to hospital staff, but the relatively low rate of infection in the wider community. Deadly, but unable to spread efficiently, and with SARS victims largely contained within hospitals, the virus burned itself out in intensive care beds across the globe.
It is for this reason that the newly reported coronavirus, principally observed in the Middle East, is of such interest. Laboratory investigations have been successful in characterizing the nature of the virus, but the true lethality of the disease and the efficiency with which it might spread can only be determined by carefully monitoring its behavior.
For epidemiologists tracking these viruses and their rapidly evolving genomes, this is an onerous task: watching and waiting, monitoring fatalities and clusters of infection, and trying to determine the right time to act.
The coronavirus now circulating in the Middle East has some worrying features: It is capable of causing destructive pneumonias and, most recently, appears to have acquired the ability to spread from person to person. Nevertheless, the risk to the general public remains low. Thankfully, the cocktail of properties required to produce a dangerous pandemic has not yet manifested. It remains then for disease surveillance officials to keep up their watch. For them, knowing the right time to put public health measures in place is a difficult balancing act. However, we should be thankful for their vigilance.
This month marks 10 years since the identification of SARS, the announcement of the WHO’s global health alert and the death of Urbani. It is an anniversary that deserves some recognition. These events set the template by which future outbreaks might be successfully contained. The experience of the 2003 SARS outbreak taught us that, when dealing with airborne viruses with pandemic potential, prevention is always better than cure.