I have good news and bad news
There are no OSX viruses of any sort except Microsoft macro viruses, so unless you choose to use Microsoft Office apps you are safe. (there was a recent attempt to make a OSX 'proof of concept virus, it was a failure as it could only be passed if it was compressed, so it could not spread itself.
Sadly to get Microsoft's API information you must pay royalties to Microsoft per user, so unless some benefactor agrees to pay MS for every copy they give away, it is unlikely there can ever be a free MS macro virus scanner.
I tried to remain child-like, all I acheived was childish.