Serological misdiagnosis of acute liver failure associated with echovirus 25 due to immunological similarities to hepatitis A virus and prozone effect

We describe a case of acute liver failure caused by echovirus 25 (E25) in a previously healthy 2-year-old boy. Initial serological studies were consistent with hepatitis A virus (HAV), with prozone phenomenon. The similarity of E25 to HAV may obscure accurate diagnosis in some cases of hepatitis.