The UK variant of coronavirus is more infectious, so why hasn’t it spread widely in Australia?

The more virulent UK strain of coronavirus is now in Australia but not circulating widely in the community yet — it’s mostly confined to hotel quarantine.

It’s a serious threat because the B117 variant is thought to be at least 50 per cent more transmissible than previous strains.

In recent days, Victoria has toughened restrictions after finding a case of the UK variant in a hotel quarantine worker.

Queensland has had a three-day lockdown after another quarantine worker tested positive to the more contagious variant and Western Australia is just emerging from a five-day lockdown.

So if this new strain is so virulent, how come we are not seeing more cases cropping up in the community?

The answer involves luck, statistics and the…