Commonest hepatotropic virus causing increased chronic carrier state is –
**Core Concept**
The question is testing the understanding of hepatotropic viruses and their impact on chronic carrier states. Hepatotropic viruses are viruses that primarily infect the liver, leading to various forms of hepatitis. The chronic carrier state refers to the persistent infection of the virus in the host, which can lead to liver damage and other complications.
**Why the Correct Answer is Right**
The correct answer is **Hepatitis B virus (HBV)**. HBV is known to have a high propensity for establishing a chronic carrier state, with a significant proportion of infected individuals becoming chronic carriers. This is due to the virus's ability to integrate into the host's genome and evade the immune system. The chronic carrier state is a major risk factor for the development of liver cirrhosis and hepatocellular carcinoma.
**Why Each Wrong Option is Incorrect**
**Option A:** Hepatitis A virus (HAV) is primarily transmitted through the fecal-oral route and typically causes acute, self-limiting hepatitis. It does not lead to a chronic carrier state.
**Option B:** Hepatitis C virus (HCV) can cause a chronic carrier state, but it is less common than HBV. HCV is transmitted through blood-to-blood contact and can lead to liver cirrhosis and hepatocellular carcinoma.
**Option C:** Hepatitis E virus (HEV) is primarily transmitted through the fecal-oral route and typically causes acute, self-limiting hepatitis. It does not lead to a chronic carrier state.
**Clinical Pearl / High-Yield Fact**
HBV is the most common cause of chronic liver disease and hepatocellular carcinoma worldwide. The chronic carrier state can be identified by elevated liver enzymes, positive HBV DNA, and the presence of HBsAg in the blood.
**Correct Answer:** B. Hepatitis C virus (HCV)