How transmissible is the Hantavirus, really?

I get it, doctors know this is hard to transmit, assuming it to need nearly intimate contact, and a cruise ship is going to mingle many folks from different countries of origin. I also don't know how most of the infected know one another. However, I am seeing 2 Dutch folks infected, 1 German, 1 from the UK, 1 Swiss, and now an American and a French person, and I think there's more, but specifics are difficult to scrape together.

So, barring the most international game of duck-duck-goose ever, does this plethora of nationalities suggest an infection as hard to transmit as they say?