it's a liability issue.  the bed bugs might spread and bring risk of lawsuit or related workman's comp claims.  they're better off erring on the side of caution since it can be seen as a reasonable and foreseeable risk under OSHA/OSA laws.

How did they find out you had bed bugs at home?

Look, I'm sorry. Didn't mean to come off judgemental. But you have GOT to get rid of that mattress, and soak the whole place down with bug bombs and disinfectants.

to expand on this a bit, yes, management was absolutely correct to send you home for this. but to be honest, i'm surprised they did. i've gone to work sick with the flu, sniffling and snotting and coughing everywhere, i've gone to work after complaining of nausea, i've gone to work hung over, stoned off my ass, not having showered for 4 days, not having shaved for a week, and never been sent home. i've seen other people come in to work with pinkeye and not be sent home - needless to say, the store developed a pinkeye outbreak shortly thereafter.

generally, retail doesn't care what condition you're in, if you're on the schedule, your body needs to be in the store. your case of bedbugs is an unusual exception and i really am surprised they didn't just look the other way. but again, your management did the right thing by sending you home.

i would recommend taking this time off to evaluate your living situation and do something about your infestation - nocturnia is correct, there's no excuse for bedbugs in 2013 

a dept head at my store had bed bugs - she lives in an apartment complex and it spread to her unit from someone else's! don't assume someone is irresponsible and lives in filth because they got bed bugs! My brother also had them before when he was living in a dorm room. Again, spread from someone else's room.