Influenza on a remote island

I was interested to read the paper by Finnie et al. ¹ on the impact of influenza on small and sometimes isolated communities. What might be considered the more interesting question is, how does the influenza virus spread to closed and/or remote communities in the first place? For example, the island of Tristan da Cunha, an island that is a British dependency in the south Atlantic ocean, the most remote inhabited archipelago in the world and nearly 2000 miles from the nearest mainland.

A previous study looked at just this conundrum. In 1971 an epidemic of influenza (Hong Kong H3N2) followed the arrival of the ship Tristania aboard which were cases of influenza. It affected 96% of the 284 islanders, and curiously one-third developed two separate illnesses during the one epidemic. ² Sounds otherwise straight forward but Sir Fred Hoyle FRS and Professor Chandra Wickramasinghe, both astronomers, argued that there was another possible explanation. ³ A pathogenic cloud containing influenza viral particles had descended through the atmosphere from a passing comet visiting our Solar System and infected both passengers on the Tristania and islanders on Tristan da Cunha. Fanciful, maybe, but at least it squares with the origin of the word influenza, ‘influence of the stars’.