Acute Viral hepatitis A & E are diagnosed by
**Core Concept**
Acute viral hepatitis A and E are diagnosed based on serological markers that indicate a recent or current infection. These markers can be detected in the blood, and their presence helps differentiate between acute and chronic hepatitis.
**Why the Correct Answer is Right**
The diagnosis of acute viral hepatitis A and E mainly relies on the detection of IgM antibodies against the hepatitis A virus (HAV) and hepatitis E virus (HEV). IgM antibodies are the first line of defense against viral infections and are produced in response to the initial exposure to the virus. The presence of IgM anti-HAV and IgM anti-HEV antibodies indicates a recent or acute infection. This is in contrast to IgG antibodies, which are produced later in the course of the infection and indicate immunity or a past infection. The liver function tests (LFTs) may also be abnormal, showing elevated levels of liver enzymes such as alanine transaminase (ALT) and aspartate transaminase (AST), but these are not specific to viral hepatitis.
**Why Each Wrong Option is Incorrect**
**Option A:** Elevated liver enzymes (e.g., ALT, AST) alone are not sufficient to diagnose acute viral hepatitis A and E, as these enzymes can be elevated in other conditions such as alcoholic liver disease, drug-induced liver injury, or other forms of hepatitis.
**Option B:** Serological tests for other forms of hepatitis, such as hepatitis B or C, are not relevant to the diagnosis of acute viral hepatitis A and E.
**Option C:** Imaging studies, such as ultrasound or CT scans, may show changes in the liver, but these are not specific to viral hepatitis and cannot diagnose the infection.
**Clinical Pearl / High-Yield Fact**
The presence of IgM antibodies against HAV or HEV is a key diagnostic criterion for acute viral hepatitis A and E. It's essential to note that the IgM antibody response can be transient, and the antibodies may disappear within 6-12 months after the infection.
**Correct Answer:** D.