Sick people in house (just a rant)

I currently live with my mother and I have a 14 month old son. Well my "dad" is staying here in his camper til my sisters step kids go back home at the end of this month and he's been coughing and says he's had fever and the poops (sorry tmi) but keeps coming in the house coughing every damn where and won't go to the hospital bc he says you need an id (which I told him he didnt need) and its pissing me off bc my son's never gotten a flu shot and if he has the flu and my son gets it I will be furious! I'm so tired of him being here and definitely tired of him coughing everywhere spreading his nasty ass germs.. I don't need my baby sick bc some idiot only thinks of himself.. My son has asthma so it could be deadly if he catches the flu.. I don't know what to do bc there's no avoiding him.. I'm just so mad!