@enozlas – heres a link (had it at hand with my SIL testing positive today) if you are really interested but I believe that in Australia you need to live with someone to be a close contact. Here the category is slightly wider than that. https://www.health.govt.nz/covid-19-novel-coronavirus/covid-19-health-advice-public/covid-19-information-household-and-close-contacts?fbclid=IwAR3x4yl_xo__T04l1xkoBzOX8lIDqFu0mHh2Q78iZhZ174S2rjvipv9T1t8#:~:text=What%20does%20it%20mean%20if%20I%20am%20a%20Close%20Contact,using%20a%20Rapid%20Antigen%20Test
The other thing is that our first omicron peak with both BA.1, BA.2 and to a much smaller extent Delta is moving through the country currently unlike over there, where the second wave BA.2 is at play.
It is not uncommon here (and probably in some SSN teams) that the players live together so in that situation if one tests positive then the other/s become close contacts and need to isolate.
I hope that helps.
