A new study says that the number of hepatitis C infections has nearly tripled in the United States in the last five years, and this is prevalent among young people in their 20s. The bloodborne virus is transmitted by injection drug use, dirty needles, blood transfusions and sex. Chronic infection can lead to cirrhosis or cancer of the liver. Hepatitis C is the top infectious disease killer in the nation, taking nearly 20,000 lives in 2015, said the Centers for Disease Control and Prevention. Experts say the rise of the opioid epidemic, with increasing numbers of people sharing needles to inject heroin and prescription painkillers, is driving the increase in cases. “New hepatitis C virus infections are increasing most rapidly among young people, with the highest overall number of new infections among 20- to 29-year-olds,” said a statement from the CDC. “This is primarily a result of increasing injection drug use associated with America`s growing opioid epidemic.” People with hepatitis C often have no symptoms, so they are unaware of their infection. The CDC said the number of new cases reported to the federal agency was 850 in 2010, and rose to 2,436 cases in 2015. However, this “does not reflect the true scale of the epidemic. CDC estimates about 34,000 new hepatitis C infections actually occurred in the US in 2015,” said the statement. Three-quarters of the 3.5 million Americans living with hepatitis C were born from 1945 to 1965.