Using Digital Surveillance Tools for Near Real-Time Mapping of the Risk of International Infectious Disease Spread: Ebola as a Case Study

Sangeeta Bhatia; Britta Lassmann; Emily Cohn; Malwina Carrion; Moritz U.G. Kraemer; Mark Herringer; John Brownstein; Larry Madoff; Anne Cori; Pierre Nouvellet

In spite of the manual curation of the data carried out by outbreak analysts at ProMED and HealthMap, substantial issues remained in the quality and consistency of the data feeds. Dealing with issues such as missing data and inconsistent records will be a key challenge in using these data for prospective real-time analysis. Despite these challenges, we show the potential of digital surveillance tools to 1) inform early detection, 2) characterise the spread, and 3) forecast the future trajectory of outbreaks. Particularly in an evolving outbreak scenario, when information from traditional surveillance is limited and only available with a significant delay, digital surveillance data can be used to complement the information gap. For instance, during the West African Ebola epidemic, the first situation report by the WHO was published only at the end of August 2014 [27] , reporting on cases between January and August 2014. On the other hand, the first post on ProMED on Ebola cases in Guinea appeared in March 2014 [28] . Development of tools that can directly be plugged into the current digital surveillance ecosystem should therefore be a growing area of focus.