Frightening: a single flight from Delhi to Hong Kong has so far led to 47 imported cases (& counting). All were required to do pre-departure testing and all were tested upon arrival. Yet, most of the cases were detected in hotel quarantine (most detected on day 12). https://t.co/EGEJMurNUR

— Dr. Karen Grépin (@KarenGrepin) April 18, 2021