Further, the researchers were surely in the 18-49 age bracket. CDC’s estimates for the 2017-18 flu season in that age bracket were 58.8 per 100,000. That is 0.0588% per person per year.
And that’s the whole flu season. To have odds of being hospitalized in november you’d cut that in four at least.
And then the odds of three people in the same lab all needing hospitalization also needing hospital treatment? Even less likely.
Not impossible, but it’s not so simple as suggesting there was a bad flu season. There wasn’t in china then, and flu hospitalization is damned rare in non elderly.
https://www.cdc.gov/flu/about/burden/2017-2018.htm
(It is possible that the “hospital care” in the article doesn’t match “hospitalization” as cdc defines it, but any kind of hospital care for a young person from the flu is still rare)