I read a survey years ago that said Australian women were the most promiscuous in the Western world. This seems to confirm that.
The article did not mention the sex of the back packers. In hostels, people are mostly tourists on a budget. That’s people of both sexes. Probably most of the illicit sex was between tourists. Thus, they are spreading STDs all over the globe.
I wonder if the survey you read years ago was truly scientific or published by some barefoot cruise company trying to get more young men aboard for their Sydney cruises.
IOW, one has to assume Aussie gals are promiscuous rather than deduce it from the article.