<prompt> Most common chronic viral illness is caused by:Hepatitis AHepatitis BHepatitis CHepatitis D  <response>: Ans. c Hepatitis CRef.: Harrison 18th edition, chapter 306 Chronic hepatitis follows acute hepatitis C in 50-70 of cases; chronic infection is common even in those with a return to normal in aminotransferase levels after acute hepatitis C, adding up to an 85 likelihood of chronic HCV infection after acute hepatitis C. Infection at birth with hepatitis B is associated with clinically silent acute infection but a 90 chance of chronic infection, while infection in young adulthood in immunocompetent persons is typically associated with clinically apparent acute hepatitis but a risk of chronicity of only approximately 1. 