There is no Google Redirect Virus for Macs running MacOS X. You do not have a virus. There are no MacOS X viruses. Honest, despite what the Windows users tell you, you don't have one unless you are also running Windows on your Mac and it is the Windows side with it. The anti virus software (assuming it is legitimate) didn't find anything because there was nothing to find. If you are using Safari for your browser, just delete the cache in the preferences and delete the history. Or you can just click on "Reset Browser". If you are running Firefox, just do the same for it. And turn on the popup ad blocker!
Again, there are no active MacOS X viruses, hasn't been one since 2006. There are a handful of Mac trojans which you would have to download and install with your admin password. They are in illegal torrents of Photoshop, iWorks 09, and Snow Leopard. They are also in fake software to view porn and fake antivirus software.
If you are still worried, then try the 30 day demo of MacScan, it will remove tracking cookies and any trojans which you may have installed.