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

(1) fewer opportunities for Zika virus introductions into Cuba in 2015 when introductions were occurring elsewhere in the Caribbean (Faria et al., 2017; Metsky et al., 2017) , (2) differences in environmental conditions in 2016 lowering the susceptibility for Ae. aegypti-borne virus outbreaks, and (3) Ae. aegypti surveillance and control campaigns (Gorry, 2016; Reardon, 2016) limiting virus transmission. To investigate the likelihood of each hypothesis, we examined international travel patterns, yearly transmission of dengue virus (also vectored by Ae. aegypti), local weather conditions, and news reports. Comparing all three hypotheses, we found that conditions in Cuba could likely have supported a large Zika outbreak in 2016, but that it may have been delayed by a countrywide Ae. aegypti control campaign (Fig. 4) .