He should be fine, his Australian girlfriend should help him out with the normal stuff here.
One thing that might be useful, when visiting the US many Americans would express concern about Australian spiders. I explained that it wasn't really much of an issue, you just make sure to check for spiders before putting your hands in places, putting on shoes, etc.
The shoes thing seemed particularly outrageous to them. It's pretty simple though, you just look at your shoes before putting them on. Any spiders in there? Any sign of webs? Don't put them on. Easy!
When testing just remember, any positive at all, no matter how faint, means you are infectious.