Tracking introductions of SARS-CoV-2 into Hawaii
Channel: ButlerLab
Date: 2022-06-30

Ethan Hill talks about using genomic sequencing data of SARS-CoV-2 in Hawaii to reveal imports to and exports from Hawaii. We constructed a tree, or genealogy, of the virus from Hawaii compared to millions collected from around the world, and applied sophisticated mathematical models to reveal when and where imports and exports occurred.  The analyses recovered 1,268 imports into the state, with substantial increases following relaxation of pre-travel testing requirements, doubling each time a testing requirement was lifted whether for interstate or inter-island travel. Lifting quarantine restrictions while pre-travel testing was in place had little effect. All variants of concern originated from various international localities. However, the Alpha and Delta variants were primarily introduced from US mainland localities and took months to arrive to Hawaii, whereas Omicron was primarily introduced from international sources and arrived to Hawaii in a matter of weeks. Pre-travel testing appears to be a very successful means of slowing the rate of introduction to Hawaii, keeping hospital resources available to the public throughout the pandemic, which helped to keep deaths from SARS-CoV-2 to a minimum.