There has been much interest in and varying opinion towards WHO’s recent declaration of a Public Health Emergency of International Concern related to the unexpected cluster of microcephaly and its suspected association with the explosive Zika virus epidemic in Latin America. But how does this play out in terms of WHO’s role as an authoritative agent in coordinating the international response and disseminating information? A quick analysis of twitter data indicates that WHO seems to have rapidly established a central position, at least as far as disseminating information through social media is concerned.
The above network graph is based on a sample of tweets for the first week of February gathered through twitter’s API. Each node (circle) corresponds to a twitter handle, and each link represents a retweet, with the size of each node being proportional to the number of times its posts retweeted. It’s clear that WHO has the most central position in this network, being retweeted by a vast ‘halo’ of users. Further out, we also see some influential ‘hubs’ of information, including the Wellcome Trust, Microbes and Infection, WebMD, FluTrackers, and other prominent media outlets, each closely followed by its own community of users. This is more easily seen in the graph below, with the seven largest communities in different colours (for those of you who are interested, this was done using the modularity function in Gephi). Even further out, we see more isolated connections that are generally disconnected from the main network.
If the situation in the twitterverse also reflects that in the real universe, then this should be encouraging news for WHO, whose role and position received heavy criticism following its handling of the Ebola epidemic in West Africa. It will be interesting to see whether and how this changes over time as the epidemic and the international response to Zika evolves.