The Lancet – “The world is ill prepared to respond to a severe influenza pandemic or to any similarly global, sustained and threatening public-health emergency”, concluded an investigation into WHO’s response to the 2009 H1N1 pandemic. In 2014, this unpreparedness was again exposed when the Ebola virus struck west Africa and claimed more than 11 000 lives. The continuing Zika virus epidemic highlights that lessons still need to be learned.
Most new epidemic infections are zoonotic, but not all are transmissible between humans. In a studypublished in Emerging Infectious Diseases on Dec 7, Mark Woolhouse and colleagues used virus genome sequencing and mathematical modelling to identify 37 viruses that have already shown some ability to spread between people but have not yet been the cause of an epidemic. Of greatest concern, the researchers suggest, are Middle East respiratory syndrome coronavirus (MERS-CoV), Bundibugyo ebola and Sudan ebola viruses, and several mosquito-borne viruses. Woolhouse and colleagues’ shortlist of viruses to watch has also included chikungunya, Zika, and Ebola in recent years, showing the potential of this approach. Although identification of viruses with human transmissibility adds to knowledge of which types of viruses and which circumstances are most likely to cause a pandemic, several emerging pathogens had not previously been seen in humans at all—severe acute respiratory syndrome, for example.
More can be done to predict the next pandemic threat, but when new outbreaks do occur, there remains a need for a better international response. Promisingly, WHO has launched the R&D Blueprint, which aims for rapid activation of research and development activities during epidemics. To be maximally effective, this strategy will need to work within low resource settings, which will require substantial investment and an understanding of the culture of the setting in which it will be implemented.
Undoubtedly, as the authors conclude, the first line of defence against emerging viruses is effective surveillance. But the international community must be prepared to take rapid and effective action if surveillance is to have value—the question remains, have the recent lessons of the Ebola and Zika viruses been learned?