International travelers and genomics uncover a ‘hidden’ Zika outbreak

Nathan D. Grubaugh; Sharada Saraf; Karthik Gangavarapu; Alexander Watts; Amanda L. Tan; Rachel J. Oidtman; Jason T. Ladner; Glenn Oliveira; Nathaniel L. Matteson; Moritz U.G. Kraemer; Chantal B.F. Vogels; Aaron Hentoff; Deepit Bhatia; Danielle Stanek; Blake Scott; Vanessa Landis; Ian Stryker; Marshall R. Cone; Edgar W. Kopp; Andrew C. Cannons; Lea Heberlein-Larson; Stephen White; Leah D. Gillis; Michael J. Ricciardi; Jaclyn Kwal; Paola K. Lichtenberger; Diogo M. Magnani; David I. Watkins; Gustavo Palacios; Davidson H. Hamer; Lauren M. Gardner; T. Alex Perkins; Guy Baele; Kamran Khan; Andrea Morrison; Sharon Isern; Scott F. Michael; Kristian G. Andersen

The recent Zika epidemic in the Americas is a testament to how rapidly mosquito-borne viruses can emerge and spread, and has revealed flaws in our surveillance and response systems (Grubaugh et al., 2018a; Morens and Fauci, 2017) . Due, in part, to high rates of subclinical infections and overlapping symptoms with infections from dengue and chikungunya viruses (Mitchell et al., 2018) , Zika virus was circulating for more than a year and a half before it was first detected in Brazil (Faria et al., 2017) . By the time Zika virus was discovered in May of 2015 (Zanluca et al., 2015) and recognized for its ability to cause severe congenital disease (França et al., 2016; Mlakar et al., 2016) , the virus had already spread from Brazil to more than 40 countries (Faria et al., 2017; Grubaugh et al., 2017; Metsky et al., 2017; Thézé et al., 2018) . By mid 2017, reports from the Pan American Health Organization (PAHO, 2017a) revealed Zika virus activity throughout the Americas was waning, prompting predictions for the end of the epidemic (e.g. (O'Reilly et al., 2018) ) and the removal of the World Health Organization's (WHO) "Public Health Emergency of International Concern" status (WHO, 2016a (WHO, , 2016b .