Viral Hepatitis comes in a number of flavors, named HAV, HBV, HCV, HDV, and HEV (not to mention any subtypes). HCV, identified as recently as 1990, is a serious form of Hepatitis causing cirrhosis of the liver, chronic infection, and often hepatocellular cancer. Prior to 1990, the most common way to become infected was through transfusion with contaminated blood. However, after identifying the virus, tests became available to prevent this form of passage, leaving the primary mode of transmission being sharing of needles between IV drug users and sexual contact.
Unlike other viruses (HAV), few people ever clear HCV and, instead, become chronically ill. This may, in part, be due to the inability of the body to generate protective, neutralizing antibodies. Those antibodies that are produced are mostly usable only as markers of disease. Symptoms of disease include fatigue, nausea, vomiting, loss of appetite, abdominal pain, jaundice, dark urine, and clay colored feces. The CDC definition of a case is: (sorry this isn’t clearer)

Serum alanine aminotransferase (ALT) levels greater than 400 IU/L indicate hepatocellular damage. This enzyme is normally found only in
liver cells, but is released into the blood when these cells are injured. Normal ALT should not exceed 60 IU/L, providing a fairly clear measure of cell injury.This can be seen clearly below as serum levels of ALT spike with symptoms of disease and then return (however not down to normal, ‘healthy’ amounts) to lower levels following resolution of symptoms.

There is no vaccine against HCV, so the best way to avoid it is to avoid contact with blood or other bodily fluids that may be contaminated.

Don’t forget to check out my comments on the novel ‘Rosemary’s Baby’ on my other blog. I highly recommend this book to anyone who enjoys thrillers / light horror (a la Stephen King).