Hepatitis: A Primer on Evaluation and Treatment Paradigms

Hepatitis is a condition characterized by liver inflammation, often caused by viral infections. It presents in both acute and chronic forms, with varying degrees of severity and potential complications. The primary viral agents responsible for hepatitis are hepatitis A, B, C, D, and E viruses (HAV, HBV, HCV, HDV, and HEV). Each type has distinct epidemiology, transmission routes, and clinical outcomes.

Hepatitis A (HAV) is caused by the hepatitis A virus, a non-enveloped RNA virus, and is primarily transmitted through the fecal-oral route, often via contaminated food or water. Symptoms include fever, fatigue, jaundice, and abdominal pain. Diagnosis is through serological tests for anti-HAV IgM antibodies, and treatment involves supportive care with vaccines available for prevention [1]. 

Hepatitis B (HBV), caused by a DNA virus, is transmitted through blood borne routes, sexual contact, and perinatally from mother to child. Acute infection may be asymptomatic or cause jaundice, fatigue, and abdominal pain, while chronic infection can lead to cirrhosis and hepatocellular carcinoma. Diagnosis involves serological tests for HBsAg, anti-HBc, and anti-HBs antibodies, as well as HBV DNA tests. Treatment includes antiviral medications such as tenofovir and entecavir, with vaccines available for prevention [2]. 

Hepatitis C (HCV) is caused by an RNA virus and is transmitted primarily through blood borne routes, such as needle sharing, and less commonly through sexual contact and perinatally. Acute infection is often asymptomatic, but chronic infection can lead to cirrhosis and liver cancer. Diagnosis includes serological tests for anti-HCV antibodies and HCV RNA PCR for confirmation. Treatment involves direct-acting antivirals (DAAs) such as sofosbuvir and ledipasvir [3]. 

Hepatitis D (HDV), an RNA virus that requires HBV for replication, is transmitted similarly to HBV. It exacerbates HBV infection, increasing the risk of severe liver disease. Diagnosis involves serological tests for anti-HDV antibodies and HDV RNA tests. Treatment is limited to pegylated interferon-alpha, with no specific antiviral treatment for HDV [4]. 

Hepatitis E (HEV), caused by an RNA virus, is transmitted via the fecal-oral route, often through contaminated water. Symptoms include jaundice, fatigue, and abdominal pain, with severe cases particularly in pregnant women. Diagnosis involves serological tests for anti-HEV IgM, IgG antibodies, and HEV RNA tests. Treatment is primarily supportive care, with vaccines available in some countries [5] (See Table 1). 

Table 1: Features of different types of viral hepatitis.

Understanding transmission routes is crucial for hepatitis prevention. HAV and HEV spread through contaminated food and water, while HBV, HCV, and HDV are primarily blood borne. Key risk factors include unprotected sexual contact, intravenous drug use, and lack of access to clean water and sanitation.

Diagnosis involves a combination of clinical evaluation and laboratory testing. Serological assays detect antibodies and antigens specific to each hepatitis virus, while molecular techniques such as PCR provide definitive confirmation and quantification of viral RNA or DNA.

Treatment varies by hepatitis type: HAV and HEV infections are usually self-limiting and require supportive care. HBV is managed with long-term antiviral therapy to suppress viral replication. HCV can be cured with DAAs, while HDV treatment is limited to interferon therapy with variable success rates. 

Prevention strategies include vaccination (available for HAV and HBV), safe sex practices, harm reduction for intravenous drug users, and improving sanitation and access to clean water.

Hepatitis remains a major global health issue, with distinct challenges associated with each virus type. Advances in diagnostics and treatment, particularly for HBV and HCV, offer hope for reducing the burden of liver disease. Ongoing public health efforts are essential for prevention, early detection, and effective management of hepatitis.

1. World Health Organization (WHO). Hepatitis. Retrieved from Online.
2. Centers for Disease Control and Prevention (CDC). Viral Hepatitis. Retrieved from Online.
3. Terrault NA, Lok ASF, McMahan BJ, Chang KM, Hwang JP, et al. (2018) Update on Prevention, Diagnosis, and Treatment of Chronic Hepatitis B: AASLD 2018 Hepatitis B Guidance. Hepatology. 67: 1560-1599.
4. Pawlotsky JM (2018) EASL Recommendations on Treatment of Hepatitis C 2018. Journal of Hepatology. 69: 461-511.
5. Wedemeyer H (2020) Hepatitis D. The Lancet. 396: 979-993.