Probably not. There aren't any viruses out there for OS X to tangle with. Now malware is a different story - see Thomas Reed's excellent Mac Malware Guide.
If you really feel that you MUST have some sort of malware/av software, however, I can recommend both Sophos for Mac and ClamXav - I've tested and evaluated both (but they never found anything - also see Mr. Reed's virus detection rate tests - http://www.thesafemac.com/mac-av-detection-rates/ and the follow-up - http://www.reedcorner.net/mac-anti-virus-testing-01-2013/.
So the 'short' answer to your question is no, not really, but if you're justa wee bit on the paranoid side, use one of the free apps mentioned above.