Hi Julia,
BowBridge AntiVirus Bridge is not "based on" ClamAV, it comes with McAfee and SOPHOS virus scanning engines built-in, but it can leverage ClamAV (either locally or on a remote server) using the native ClamAV protocol.
You may also connect to ClamAV (as well as Symantec, Trend Micro, Kaspersky, MetaScan etc..) via the ICAP protocol.
Actually, quite a few of our customers use ClamAV as a "second opinion" scanner or for the Non-Prod environments.
best,
Jörg