From: Investigating the utility of Google trends for Zika and Chikungunya surveillance in Venezuela
Disease
Lag in weeks
−3
−2
−1
0
+ 1
+ 2
+ 3
Chikungunya
0.564
0.677
0.745
0.784
0.734
0.666
0.585
Zika
0.618
0.660
0.671
0.705
0.754
0.753
0.710