A Review of Acute Viral Hepatitides Including Hepatitis E

Acute viral hepatitis (AVH) is a systemic infection, caused by a group of viruses, which have special affliction and primary site of replication in the liver [1]. As of today, five unelated hepatotropic pathogens have been identified to cause AVH. These include the hepatitis A virus (HAV), the hepatitis B virus (HBV), the hepatitis C virus (HCV), the hepatitis D virus (HDV), and the hepatitis E virus (HEV). However, varying proportion of AVH cases fall in to the non-A-E group and are in search of putative agent/s. This includes 2–30% cases of sporadic AVH [2], 30–55% cases of acute liver failure [3], and most cases of giant-cell hepatitis (postviral hepatitis) aplastic anemia [4]. Over the years, several viruses have been identified and all are in search of disease. Transfusion-transmitted agents, namely human pegivirus (HPgV) (formerly known as GBV-C/HGV), TT virus, and other TTV-related viruses (SANYAN, YONBON, SEN viruses, and TTV-like Mini virus), have been identified but do not cause AVH [5]. There have been new kids on the block of whom we must learn more about in future. Two more novel agents in the pegivirus genera of the family Flaviviridae have been identified and named as human hepegivirus 1 (HHpgV-1) [6] and human pegivirus 2 (HPgV-2) [7]. A number of systemic viral infections that may involve liver and cause hepatitis include Epstein-Barr virus infection, cytomegalovirus infection, herpes simplex virus infection, Varicella-Zoster virus infection, and severe acute respiratory syndrome [8].