Virus in the house?

There's some virus attacking on the family recently.

Wifey and Cait were the first to get infected due to indigestion and wind in stomach, as well as vomiting. Both of them were very pale when hubby sent them to clinic. 

Unfortunately, there are too many people (around 10 over people!), so they decided to go to another clinic which have lesser crowds. Cait had pill injected into her buttock, while wifey had an injection. 

Just when both of them are recovering, something had happened to dad.

Hubby's dad is resting at home for 2 weeks due to cataract operation on both of his eyes. He is to banned from doing housework and carry heavy things.

2 days ago, while he was sitting down, looking at his mobile, he felt something unusual. He kept calling for someone, but no one know what is going on. Mom was asleep with Cait, while wifey was working in the room even though she is on MC as well. 

She heard dad calling but thought it was Cait. 

Just when mom came out from the room, she saw dad sitting on the floor, lying against the wooden carpentry behind him, having both his arm wide open resting on the chair and look as if it is like a wing.

Immediately, mom applied some ointment on his nose and asking what is happening. Calling dad a few times, he did not response at all. He seem fainted. 

Wifey called hubby home immediately as he was out meeting and picking Clar from school. When he got home, dad was feeling a lot better after he vomited everything out.

Could it be a virus or is it because of the food he had it earlier at one of the food court? After asking dad  few more question, he seem to black out for a while because he felt really uneasy at that time. He was told to rest and not doing anything at all. 

After observing him for 2 days, he is much better than before. 

3 out of 6 family members were down with this sickening unknown virus. Let's hope it is gone by now.