What is hepatitis C virus?
Hepatitis C is a virus that is transmitted through the blood and causes hepatitis C which affects the liver. According to the WHO, “worldwide, an estimated 71 million people are chronically infected with the hepatitis C virus and a significant number develop cirrhosis or cancer of the liver.” In 2016, an estimated 3,99,000 people died worldwide from hepatitis C.
How did they find out about a new virus?
- Harvey J. Alter, who was studying hepatitis in patients who received blood transfusions, discovered many unexplained infections. Tests for hepatitis A and hepatitis B virus infection showed that they were not the cause.
- His team has shown that the blood of these patients can transmit the disease to chimpanzees, and other studies have shown that an unknown infectious agent is behind this. The new and mysterious disease has been named “not A, not B” hepatitis.
- This new virus could not be isolated for several years using traditional virus isolation techniques. Michael Houghton and his team created a collection of DNA fragments from the blood of an infected chimpanzee and carefully recorded it. They found a new RNA virus belonging to the Flavivirus family and named it hepatitis C virus.
- To figure out whether this new virus alone could cause hepatitis, Charles M. Rice used genetic engineering, generated an RNA variant of the virus, and injected it into the livers of chimpanzees.
- The virus was detected in the blood and the chimpanzees showed changes similar to those seen in humans with the disease. This was the final proof that the virus alone was the cause of the unexplained cases of transfusion hepatitis.
Why is this discovery important?
- The findings of the three Nobel Prize winners helped design sensitive blood tests that eliminated the risk of transfusion-transmitted hepatitis. Their discovery also led to the development of antiviral drugs targeting hepatitis C. It raised hopes of eradicating the virus from the world’s population.