Acute Viral Hepatitis (HBT - GI)

Summary

This video provides an in-depth overview of acute viral hepatitis, focusing on the five main hepatitis viruses: A, B, C, D, and E. The presenter explains their classification (RNA or DNA), transmission routes, and clinical features, emphasizing key diagnostic markers like IgM and IgG antibodies. Hepatitis B is highlighted as the only DNA virus among them, while hepatitis D is a defective RNA virus requiring co-infection with hepatitis B. The video also discusses the genotypic variation of these viruses, the clinical significance of specific genotypes, and the importance of understanding their unique characteristics for proper diagnosis and treatment.

Takeaways

• 😀 Hepatitis A (HAV) is a non-enveloped RNA virus that is transmitted via the fecal-oral route and typically causes acute liver inflammation.
• 😀 Hepatitis B (HBV) is the only DNA virus among hepatitis viruses and is transmitted via blood and bodily fluids, with 10 genotypes and various subtypes.
• 😀 Hepatitis D (HDV) is a defective RNA virus that requires Hepatitis B for replication and is often seen in co-infection or superinfection with HBV.
• 😀 Hepatitis C (HCV) is an RNA virus with 8 major genotypes, and is often associated with chronic liver disease and a higher risk of cirrhosis.
• 😀 Hepatitis E (HEV) is an enterically transmitted RNA virus that is prevalent in areas with poor sanitation, with genotypes 1 and 2 being more virulent.
• 😀 Hepatitis A virus (HAV) markers include IgM anti-HAV during the acute phase and IgG anti-HAV during convalescence.
• 😀 Hepatitis B virus (HBV) markers include HBsAg, HBV DNA, and IgM anti-HBc to diagnose acute infection and assess viral load.
• 😀 Hepatitis C virus (HCV) markers include Anti-HCV for screening and HCV RNA for confirming active infection and assessing treatment efficacy.
• 😀 Hepatitis D virus (HDV) cannot replicate without the help of Hepatitis B and is more severe when co-infected with HBV.
• 😀 Hepatitis E virus (HEV) is diagnosed by detecting IgM and IgG anti-HEV, and it typically resolves on its own, but can be severe in certain populations.

Q & A

What is acute viral hepatitis and how is it caused?

Acute viral hepatitis is inflammation of the liver caused by infection with one of several hepatitis viruses, including HAV, HBV, HCV, HDV, and HEV. Each virus has distinct transmission modes and genetic characteristics.

How do the five hepatitis viruses differ in terms of their genetic makeup?

Hepatitis A, C, and E are RNA viruses, while Hepatitis B is the only DNA virus among them. Hepatitis D is a defective RNA virus that requires Hepatitis B to replicate.

What are the key markers used to diagnose Hepatitis A infection?

The key markers for Hepatitis A are IgM anti-HAV, which appears during the acute phase, and IgG anti-HAV, which is detectable during the recovery phase.

What is the role of Hepatitis B in the co-infection with Hepatitis D?

Hepatitis D requires Hepatitis B to replicate. It is often seen in patients who are either co-infected with HBV or have a chronic HBV infection.

What are the common genotypes of Hepatitis B in the United States and Asia?

In the United States, Hepatitis B is predominantly caused by genotypes A and D. In Asia, genotypes B and C are more common.

How does Hepatitis C differ from other hepatitis viruses in terms of genotype and disease progression?

Hepatitis C has 8 major genotypes, with genotype 3 being particularly associated with hepatic steatosis and a high risk of progressing to chronic liver disease.

Why is Hepatitis E considered an enterically transmitted virus?

Hepatitis E is primarily transmitted via the fecal-oral route, often due to contaminated water, making it an enterically transmitted virus.

How does the structure of Hepatitis B virus differ from the other hepatitis viruses?

Hepatitis B is the only hepatitis virus with a DNA genome and an enveloped structure, while the others (A, C, D, and E) are RNA viruses, with Hepatitis D being a defective RNA virus.

What is the significance of the genotype variations in Hepatitis viruses?

The different genotypes of Hepatitis viruses affect the severity of the disease, with certain genotypes associated with milder or more severe forms of infection. For example, Hepatitis D genotype 1 is the most common, while genotype 3 of Hepatitis C is linked to more severe liver damage.

How is Hepatitis A transmitted and what are its main characteristics?

Hepatitis A is transmitted primarily through the fecal-oral route, often via contaminated food or water. It is a self-limiting infection, with IgM anti-HAV indicating the acute phase and IgG anti-HAV marking recovery.