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Review
. 2021 Jul 28;27(28):4603-4638.
doi: 10.3748/wjg.v27.i28.4603.

Viral hepatitis: Milestones, unresolved issues, and future goals

Pietro Torre  1 , Andrea Aglitti  1 , Mario Masarone  1 , Marcello Persico  2
Affiliations
Review

Viral hepatitis: Milestones, unresolved issues, and future goals

Pietro Torre et al. World J Gastroenterol. .

Abstract

In this review the current overall knowledge on hepatitis A, B, C, D, and E will be discussed. These diseases are all characterized by liver inflammation but have significant differences in distribution, transmission routes, and outcomes. Hepatitis B virus and hepatitis C virus are transmitted by exposure to infected blood, and in addition to acute infection, they can cause chronic hepatitis, which in turn can evolve into cirrhosis. It is estimated that more than 300 million people suffer from chronic hepatitis B or C worldwide. Hepatitis D virus, which is also transmitted by blood, only affects hepatitis B virus infected people, and this dual infection results in worse liver-related outcomes. Hepatitis A and E spread via the fecal-oral route, which corresponds mainly to the ingestion of food or water contaminated with infected stools. However, in developed countries hepatitis E is predominantly a zoonosis. Although hepatitis A virus and hepatitis E virus are usually responsible for a self-limiting hepatitis, a serious, rarely fatal illness is also possible, and in immunosuppressed patients, such as organ transplant recipients, hepatitis E virus infection can become chronic. The description of goals achieved, unresolved issues, and the latest research on this topic may make it possible to speculate on future scenarios in the world of viral hepatitis.

Keywords: Hepatitis A; Hepatitis B; Hepatitis C; Hepatitis D; Hepatitis E; Viral hepatitis.

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Conflict of interest statement

Conflict-of-interest statement: Authors declare no conflict of interests for this article.

Figures

Figure 1
Figure 1
Sustained virological response rate of hepatitis C virus antiviral treatment, from interferon to direct-acting antiviral agents’ regimens. SVR12: Sustained virologic response 12 wk post-treatment; IFN: Interferon; RBV: Ribavirin; peg-IFN: Pegylated interferon; PI: Protease inhibitor; SMV: Simeprevir; SOF: Sofosbuvir; LED: Ledipasvir; GLE: Glecaprevir; PIB: Pibrentasvir; VEL: Velpatasvir.
Figure 2
Figure 2
Indications for anti-hepatitis B virus therapy according to international guidelines. HBV: Hepatitis B virus; HCV: Hepatitis C virus; HDV: Hepatitis D virus; HCC: Hepatocellular carcinoma; HBeAg: Hepatitis B E antigen; HBsAg: Hepatitis B surface antigen; CHB: Chronic hepatitis B; ALT: Alanine aminotransferase; ULN: Upper limits of normal; DAA: Direct-acting antiviral agents.
Figure 3
Figure 3
Classification, hosts, and ways of transmission of the hepatitis E virus. HEV: Hepatitis E virus.
See this image and copyright information in PMC

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