Hep C is a serious disease, and there is definitely the possibility that this will lead to your inadmissibility to Canada.
http://www.cic.gc.ca/english/department/partner/pp/pdf/IMEI_Hepatitis.pdf
Did you just find out about this in the medical exam, or did you know about it before? Are you receiving treatment?
Basically, you will have to demonstrate that your disease is not a significant burden for Canadian medical services and you do not pose a risk to Canadian public health.
This is a tricky one. I recommend you get medical as well as legal advice.