Colds

“There's some kind of bug going around.”

It's winter. A lot of people that you work with are getting sick with colds and flus. You're worried that you're going to get sick too. You're talking to your wife about it.

There's some kind of bug going around.

some kind of (something)  - The phrase "some kind of ___" can be used when you don't know exactly what you're talking about or you don't want to specify:

What's this? Some kind of stew? 

I hear some kind of siren in the background.

There's (a contagious sickness) going around. 

When a lot of people are sick with a cold, a flu, etc., you can say that it "is going around". For example:

Be careful. There's a flu going around.

 I've noticed a few people sniffling. I hope that there's not something going around.                     a bug  - You can call a slight illness like a cold, a flu, or a stomach virus a "bug".

A: Are you OK?

B: I think I got some kind of stomach bug.

The more common meaning of "bug" is insect, but when you use it this way, "bug" means a virus or bacterial infection.