Viral Hepatitis

Hepatitis A Virus (HAV)

Transmission: Fecal-oral

Presentation: Febrile illness, nausea/vomiting, diarrhea, anorexia, abdominal distension, rarely causes fulminant liver disease

Diagnosis: Hepatitis A Virus IgM

Management: Conservative management

Hepatitis B Virus (HBV)

Transmission: Blood, sex, vertical (mother-to-baby)

Presentation

• Acute: Similarly to Hepatitis A: Febrile illness, nausea/vomiting, diarrhea, abdominal pain. Rarely, jaundice and fulminant liver disease.
• Chronic: 5-10% will develop chronic disease ₍₁₎. Roughly 25% of these individuals will develop Hepatocellular Carcinoma (much more likely if the patient has cirrhosis) ₍₂₎
• Associated with Polyarteritis Nodosa, mixed cryoglobulinemia (see small vessel vasculitis)

Diagnosis

• HbSAg (+) means the patient is actively infected
• Anti-HbSAg Ab (+) means the patient has either cleared an infection or an immunization
• Anti-HbCAg Ab (+) means the patient has been infected and is past the acute phase

Management

• Acute infection
  • Mild: Supportive treatment
  • Moderate-Severe Disease: Antiviral (Entecavir, adefovir, tenofovir)
• Chronic infection
  • Entecavir or tenofovir (or IFN-α, which has higher seroconversion rates but also higher side effect rates), though this is dependent on factors including stage of disease (immune-tolerant, etc.), liver disease, pregnancy status, immunocompetent status, etc.
  • Cirrhosis management (see Cirrhosis)

Hepatitis C Virus (HCV)

Transmission: Blood, sex, vertical (mother-to-baby)

Presentation

• Acute: Similarly to Hepatitis A: Febrile illness, nausea/vomiting, diarrhea, abdominal pain. Rarely, jaundice and fulminant liver disease.
• Chronic: ~75-85% will develop chronic disease (with roughly 10-20% of these patients developing cirrhosis over 20 years). HCC occurs at roughly 1-4% of cirrhotic patients per year ₍₃₎

Diagnosis: Anti-HCV IgG Ab

Management: Sofosbuvir and ledipasvir + cirrhosis management (see Cirrhosis)

Hepatitis D Virus (HDV)

Defective RNA virus which requires HBV co-infection for its life cycle and replication

Transmission: Blood, sex, vertical (mother-to-baby) ₍₄₎

Presentation ₍₅₎

• Acute: Similarly to Hepatitis A: Febrile illness, nausea/vomiting, diarrhea, abdominal pain. Rarely, jaundice and fulminant liver disease. May be more severe in individuals with chronic HBV who develop a superimposed acute infection with HDV rather than an co-infection with HBV and HDV at the same time
• Chronic: ~5% of individuals with co-infection will develop chronic disease, whereas ~90% patients with chronic HBV who have superinfection with HDV will develop chronic disease, which carriers a higher morbidity than chronic HBV

Diagnosis: Hepatitis B serology as above as well as HDV RNA, HDV Ag, anti-HDV IgG, and anti-HDV IgM

Management ₍₆₎

• IFN-α (only effective in ~ 20% of patients) for chronic infections
• Liver transplantation is indicated in case of liver failure.

Hepatitis E Virus (HEV)

Transmission: Fecal-oral

Presentation:

• Acute, self-limited hepatitis in immunocompetent hosts
• Chronic hepatitis in immunosuppressed patients

Diagnosis: HEV IgM

Management: ₍₇₎

• Acute (in immunocompetent): Supportive
• Chronic (in immunocompromised): Ribavirin or pegylated-IFN

References

1. Acute vs. chronic hepatitis b. Hepatitis B Foundation | Baruch S. Blumberg Institute. (n.d.). https://www.hepb.org/what-is-hepatitis-b/what-is-hepb/acute-vs-chronic/. 
2. Ganem, D., & Author AffiliationsFrom the Departments of Microbiology and Immunology and Medicine and the Howard Hughes Medical Institute. (2004, June 24). Hepatitis b virus infection – natural history and clinical consequences: Nejm. New England Journal of Medicine. https://www.nejm.org/doi/10.1056/NEJMra031087?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub++0pubmed. 
3. Axley, P., Ahmed, Z., Ravi, S., & Singal, A. K. (2018, March 28). Hepatitis C virus and HEPATOCELLULAR Carcinoma: A NARRATIVE REVIEW. Journal of clinical and translational hepatology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863002/. 
4. Centers for Disease Control and Prevention. (2020, March 9). What is hepatitis d – faq. Centers for Disease Control and Prevention. https://www.cdc.gov/hepatitis/hdv/hdvfaq.htm#section2. 
5. Masood, U. (2021, January 23). Hepatitis d. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK470436/. 
6. Pascarella, S., & Negro, F. (n.d.). Hepatitis d virus: An update. Liver international : official journal of the International Association for the Study of the Liver. https://pubmed.ncbi.nlm.nih.gov/20880077/. 
7. Waqar, S. (2021, July 18). Hepatitis e. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK532278/.