I don't know whether HCV was involved but I did see this at Wikipedia:
".....Bruce had suffered a period of declining health, after many years of addictions which he finally beat with clinical treatment, and in 2003 was diagnosed with liver cancer. In September 2003, he underwent a liver transplant, which was almost fatal, as his body initially rejected the new organ...."
As I watched the DVD of the Cream reunion at the Royal Albert Hall from a year ago, I noticed he sat a lot on a stool as he was playing bass. As a musician myself, I felt that something was wrong. A few weeks ago I found out he had a liver transplant. Then it all fit together.
I am back entertaining after 10 months post transplant, and my voice and playing is as if nothing ever happened. I never did drugs, well some pot while at Kent State U, but nothing heavier, which may be a factor that I'm responding so well and all my strength and stamina back again. Another musician, Greg Allman of the Allman Bros. was also a heavy drugs and alcohol user for years. I hope he doesn't meet the same fate after his transplant some time ago.
Speaking of Greg Allman. Tonight will be the last performance of the Allman Bros. It was announced on NBC News that they will do the last concert in NYC.
I did find this link
there is a piece about Jack
Looking back, Bruce, 65, admits that drugs were
at the root of his problems. “I was told I had
cirrhosis of the liver and that led to cancer,” he
and this note at the end
We do not know whether or not Jack Bruce’s liver illness is hep C related. His story, though, highlights health issues that some people with hep C — albeit a small number — may eventually face. Ed