A New Approach to Monitoring Dengue Activity

Madoff, Lawrence C.; Fisman, David N.; Kass-Hout, Taha

Chan et al., in this edition of PLoS Neglected Tropical Diseases [27] , apply searchstream surveillance techniques to the monitoring of dengue. In this case, search queries appear to closely track (rather than lead) dengue activity as measured by traditional systems. The authors have limited their model to certain locations defined in part by the extent of Internet use in these areas (Bolivia, Brazil, India, Indonesia and Singapore). Their findings are exciting: when evaluated in a ''testing set'' of data not used to derive initial models, they found extremely strong correlation between denguerelated query volumes and case counts reported by traditional surveillance systems, but their approach has the advantage of both timeliness and transparency (including the availability of the system on the Google.org website).