the fact that they’re using THE bug means that this is an idiom meaning that you tried something once and liked it so much, you couldn’t stop/get enough: “The first time I left this country was on a business trip to London when I was 25. Once I was bitten by the (travel) bug, I couldn’t get enough. I even took a year sabbatical from work just to travel around.”

Interesting what idiom in Russian would fit here? иметь страстный/сильный интерес к ...? заболеть чем-то, зафанатеть от чего-то?

Actually there is already similar translation here from 4 years ago particularly about the travel. I've changed mine.