Infections found on Mac running Mountain Lion

[GenerationY]

I have attached screen shots of what Avast found on my system so far.  Anybody know anything about the severity of these infections?
If these are not false positives, this will my first viral experience with a Mac!

Also what is the difference between repairing and deleting the file that is infected?

Is one better than the other?

Thanks

[Pondus]

Mac forum section here. http://forum.avast.com/index.php?board=5.0

Also what is the difference between repairing and deleting the file that is infected?

Clean, Quarantine, or Delete?
http://antivirus.about.com/b/2007/03/11/clean-quarantine-or-delete.htm