Hepatitis C is considered to be “chronic” if it has persisted for longer than 6
months. The term “Chronic Persistent” used to be used to define hepatitis
which persisted for longer than 6 months, but which was not currently
causing active damage to the liver. The term “Chronic Active” was used to
define hepatitis which persisted for longer than 6 months, and which was
actively destroying the liver. The differentiation between “persistent”
and “active” is not commonly used any more, with the assumption being
that if the virus exists, it is causing damage whether it is moving
quickly or not.
About 85 percent of HCV-infected individuals fail to clear the virus by 6
months and develop chronic hepatitis with persistent, although sometimes
intermittent viremia. This capacity to produce chronic hepatitis is one
of the most striking features of HCV infection. The majority of patients
with chronic infection have abnormalities in ALT levels that can
fluctuate widely. About one-third of HCV patients with chronic infection
have persistently normal serum ALT levels. Antibodies to HCV or
circulating viral RNA can be demonstrated in virtually all patients with
chronic HCV hepatitis.
Chronic HCV is typically an insidious process, progressing, if at all, at a
slow rate without symptoms or physical signs in the majority of patients
during the first two decades after infection.]
A small proportion of patients with chronic HCV hepatitis - perhaps less than
20 percent - develop non-specific symptoms, including mild intermittent
fatigue and malaise. Symptoms first appear in many patients with chronic
HCV hepatitis at the time of development of advanced liver disease. If
by advanced we mean cirrhosis, then this is most definitely not the case.
Symptoms can occur well before cirrhosis occurs.
Although patients with HCV infection and normal ALT levels have been referred
to as “healthy” HCV carriers, liver biopsies can show histological
evidence of chronic hepatitis in many of these patients. - National
Institutes of Health Consensus Statement on Hepatitis C 1997
It is thus possible to have low enzyme levels and few if any symptoms and yet have dangerously advanced liver disease. The problem with this scenario is that the carrier does not know he or she is ill, and does not make modifications to his or her behavior—alcohol consumption, sexual protection, fatty foods, and so forth.