Doesn't seem like it, it's a GUI app that runs CLI commands and flags for ClamAV, which is separately installed, according to Mark Allan, the developer of ClamXav:

https://www.clamxav.com/BB/viewtopic.php?p=2386#p2386

ClamXav was never open-source, it was previously freeware/donationware.

It is listed as the only packaged solution for ClamAV, otherwise you'll need to build from source.

See: http://www.clamav.net/download.html

Edit: There is a Homebrew package: http://brewformulas.org/Clamav