Hard question. Body parts and transformation

[RedEye]

Viruses don't "eat" that way. They invade cells and use the cell's energy to replicate thenselves. Sometimes, there are other occurances, but for the most part all a virus does is reproduce, once it's in a cell.
Autopophagy isn't on the list of Viral activities. If the virus continued to live; the deleted part would become more-not less Wolfy looking.

[Midnight]

If a WW is in Gestalt form and, say, looses a hand while he's still alive. Doe the hand stay in Gesalt form or does it go back to the original form?

Any body part - what happens if it's separated from the host while the host is in Gestalt form?

If we're talking about a scientific (as opposed to magical) answer... I'd say it depends on how stable the gestalt form is. If the werewolf in gestalt form has to concentrate to keep that form instead of reverting to human (or wolf), then the hand (or other body part), once severed, should change back to the werewolf's normal shape. However, if the werewolf in gestalt form doesn't have to concentrate to keep that form, and particuarly if it would take a conscious effort to change into any other form, then the body part should remain in the form the werewolf was in when the body part was detached.

Although I suppose, logically, the same should also be the case if a werewolf was killed; and I don't know what happens in that scenario.