I was talking to a pest controller and asked about this.
Apparently they're rife nowadays, migration of people's has influenced their expansion greatly, overcrowded living conditions, more people staying in hotels etc etc etc, they're a really common problem now.
He said he always...always placed his bag/case in the bath if he's in a hotel, somewhere they can't get to, if you leave your bags on the floor they can get in very quickly and easily and you take them home with you.
Heat is a good initial bedbug killer...very hot wash for clothes and bedding, then if necessary heat the room / house as hot as you can for about 90 minutes...this will kill most if not all...but you have to make sure everything is exposed to the heat, strip bedding, expose mattresses etc etc.
Otherwise it's pesticides.
Treat it seriously he said.