<prompt> Regarding Chronic Viral Hepatitis -Hepatitis A virus infection is a common cause in childrenMorphological classification into Chronic Active Hepatitis and Chronic Persistent Hepatitis are importantFatty change is pathognomic of Hepatitis C virus infectionGrading refers to the extent of necrosis and inflammations  <response>: Classification of hepatitisIn the new classification system of Hepatitis, Grading refers to the assessment of necroinflammatory activity.Chronic hepatitis represents a series of liver disorders of varying causes and severity in which hepatic inflammation and necrosis continue for at least 6 months.Earlier chronic hepatitis was categorized into three types depending upon histopathological features. These areChronic persistent hepatitisChronic lobular hepatitisChronic active hepatitisNow, this categorization has been replaced by more informative classification based upon a combination of clinical serological and histological variables.Now the classification is based upon Its causeIts histologic activity or gradeIts a degree of progression or stagea Classification by cause In this, the hepatitis is classified according to the cause - such as viral hepatitis, autoimmune hepatitis, drug-associated hepatitis.b Classification by Grade This classification is based upon an assessment of necroinflammatory activity.An assessment of following histological features is made on liver biopsy -Periportal necrosisPiecemeal necrosisBridging necrosisPortal inflammationc Classification by stage This classification is based upon the degree of fibrosis.It reflects the levels of progression of the disease.Staging is based upon the degree of fibrosis as follows0 No fibrosis1 Mild fibrosis limited to portal tract2 Moderate fibrosis Portal and periportal fibrosis3 Severe fibrosis including bridging fibrosis4 Cirrhosis 