Probably, could be in your clothes. Hot hot shower 2-3 times a day, more if itchy, clothes straight off and straight into the hot laundry. Nice way to ruin your fine shirts but necessary. Or else lots and lots of ammonia for linen and stuff.

Put a good amount of the tea tree oil in a sesame seed oil, grapeseed oil, or olive oil base and rub it all over yourselves and the cats. Just stay at it.

brings back dreadful memories I must say.

Bathe the cats too, you probably will have to buckle and get the grocery store chemical stuff for the cats at this point. Tea tree is a deterrant, not always a quick cure.