Interesting article mate.
The way that reads is that fully understanding of where Flu originated from will probably take many years to complete.
"Humphries concedes that a final answer to the mystery of the Spanish flu's origins is still a ways off."
"What we really need is a sample of the virus preserved in a burial for the medical experts to uncover," Humphries says. "That would have the best chances of settling the debate."
The interesting thing is there are references to Kansas in the USA, see below.
"A decade after the war, Kansas was identified as another possible breeding ground, due to reports of an influenza outbreak there that spread to a nearby Army camp in March 1918, killing 48 doughboys."
It would be interesting to know the exact route of the transport, did the ships to the UK actually sail directly from Canada, or did they travel via the US, and ship from there. But I suppose there are either no records on that, or they are still classified.
Also a reference to a case in Iowa in the US, the earliest found.
"The earliest sample found so far was from a U.S. soldier who died on May 11, 1918, at Camp Dodge, Iowa, but the team is looking for earlier cases."