Two years ago this week, the WHO released its first official Disease Outbreak News report about the 2013-2016 West African Ebola outbreak. Since then, nearly 30,000 cases have been reported out of the region.
Though the outbreak has been nearing its end now for several months now, sporadic case clusters (both confirmed and otherwise) have continued to crop up in Guinea, Sierra Leone, and Liberia (click through below).
Across all three countries, both confirmed and suspected & probable cases have flat-lined since late November… More or less. It’s unclear whether the few blips we have seen since then are due to zoonotic transmission (i.e. low-level endemicity) or if they are due to outbreak-related, residual human-to-human transmission (e.g. persistent sexual transmission). As Adam Kucharski noted on Monday (in response to this post):
@maiamajumder Sequence data will be of crucial use to answer those end-of-epidemic questions
— Adam Kucharski (@AdamJKucharski) March 21, 2016
Continued surveillance will be crucial in either event, but this is far easier said than done. In the aftermath of an outbreak, already limited public resources often become increasingly scarce due to competing demands and waning public interest. Traditional surveillance (for Ebola and otherwise) likely won’t be a feasible solution for West Africa in the years ahead. However, digital disease surveillance (DDS) may help us fill knowledge gaps in the face of financial constraints.
This said, DDS is far from a perfect solution; there are still great technical (and political) strides that that have yet to be made regarding data collection, storage, and dissemination structures (among other things). Nevertheless, a mixed model the includes the the most practical components of each type of surveillance system may allow us to identify case clusters on the cheap before they have the chance to evolve into yet another full-blown outbreak… Hopefully.
Note: This post was edited on March 23, 2016 to add the above embedded tweet from Dr. Kucharski.