By Dr Ananya Mandal, MD
The ancient history of hepatitis is unknown and there has been no characterization of the virus and its typical symptoms in ancient times. This is because no specific symptoms associated with this infection are known.
However, like most other viruses, the hepatitis C virus also could have been around for hundreds of thousands of years or more evolving with time to its current genotypes and strains.
There are no blood or tissue samples from ancient ages that can confirm the presence of this virus. Since this virus is an obligate virus (it cannot survive outside a living organisms – human or primates) there is no evidence of this virus from ancient ages.
HGV/GBV-C and hepatitis C
According to some experts HGV/GBV-C could be a close relative of the hepatitis C virus affecting Old and New World primates. If this is so, then the origins of hepatitis C virus can be traced back to 35 million years ago.
This again is a speculation and cannot be confirmed. Some experts speculate that the present six types of genotypes or strains of hepatitis C virus have a confirmed ancestor that existed some 400 years ago.
The virus is spread via blood and needle sharing most commonly. Thus the knowledge of this virus came after the advent of use of needles and blood products and transfusions.
In 1957 scientists found that interferon could act as an antiviral agent. They called it interferon since it could “interfere” with replication or multiplication of the virus.
Three different types of interferon were identified – alfa, beta and gamma. Interferon was then approved to treat a variety of disorders that included hairy cell leukemia, and Kaposi’s sarcoma.
Identification of the virus
In the 1960’s and 70’s the virus was actually identified. Scientists found blood tests to detect the hepatitis B infection in 1963 and hepatitis A in 1973.
They noticed that many blood samples that seemed to infect individuals were negative for both hepatitis A and B. Scientists classified these as non-A, non-B hepatitis or NANB hepatitis.
It is now believed that approximately 90-95% of cases previously classified as NANB hepatitis were actually hepatitis C.
It was in the 1980’s that investigators from the Centers for Disease Control identified the virus.
Blood tests for hepatitis C
In 1990 blood banks began screening blood donors for hepatitis C. In 1992 a blood test was developed to effectively screen blood before it was transfused. This reduced the risk of hepatitis C through a blood transfusion to approximately 0.01%.
Recent history of hepatitis C treatment
In 1991 the FDA approved the first alfa interferon (Schering’s Intron A) in the treatment of hepatitis C.
In 1996 the FDA approved alfa interferon (Roche- Roferon A ) to treat hepatitis C.
In 1997 FDA approved consensus interferon (Amgen- now InterMune-Infergen) to treat hepatitis C.
A protocol of injection of 3 million units of interferon, three times a week for 48 weeks was developed.
In 1998 FDA approved Rebetron (Schering’s Intron A plus ribavirin) for the treatment of hepatitis C.
By this time combination therapy with interferon (Intron A - 3 million units thrice weekly) plus ribavirin (800-1200mg/day) was developed.
Clinical trials showed the efficacy of combination therapy for 48 weeks in genotype 1 and 24 weeks for genotypes 2 and 3.
It was in 2001 that pegylated interferon was approved (Peg-Intron Schering’s pegylated interferon alpha-2b). Pegylation involves attachment of a polyethylene glycol (a biologically inert compound) to the interferon to make it less likely to be removed easily from blood.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)