The key difference is that HBV refers to the hepatitis B virus, while HBsAg refers to hepatitis B surface antigen, a protein found on the surface of the HBV.
Here's a breakdown:
-
HBV (Hepatitis B Virus): This is the actual virus that causes hepatitis B infection. It's a DNA virus that infects the liver.
-
HBsAg (Hepatitis B Surface Antigen): This is a specific protein located on the surface of the hepatitis B virus. According to reference information, HBsAg can be detected in high levels in serum during acute or chronic HBV infection. Its presence generally indicates that a person is infectious, except in the transient period within 30 days after receiving a HepB vaccine. This makes it a key marker for diagnosing HBV infection.
| Feature | HBV (Hepatitis B Virus) | HBsAg (Hepatitis B Surface Antigen) |
|---|---|---|
| Definition | The virus itself that causes Hepatitis B. | A protein on the surface of the Hepatitis B virus. |
| Nature | Infectious agent. | Viral protein. |
| Significance | Causes infection, leading to liver disease. | Indicates the presence of the virus; used for diagnosis and infectivity. |
Think of it like this: HBV is the car, and HBsAg is a specific emblem on the car's exterior. Testing for HBsAg is a way to determine if the HBV "car" is present.
