Statements from the Taormina expert meeting on occult hepatitis B virus infection.

Occult hepatitis B virus (HBV) infection is one of the
most challenging topics in the field of viral hepatitis with
its virological and clinical relevance being debated for
more than 30 years. Initially described in the late 1970s,
this form of hepatitis B infection has now been further
characterised. In particular, in the last 10 years the application
of highly sensitive molecular biology techniques
has resulted in the elucidation of its virological features
and possible clinical implications. It is noteworthy that
there has been a steady and continuous increase in the
number of publications on occult HBV infection, with
many reviews, editorials and commentaries recently being
published by journals covering different areas of bio-medical
interest [1–32]. However, several aspects of occult
HBV infection are still not resolved, even including the
definition itself as well as a standardised approach for laboratory-
based detection.
An EASL endorsed international workshop on occult
HBV infection was held in Taormina (Italy) on March
7–8, 2008. Invited presentations by experts and subsequent
extensive discussions reviewed the virology and
immunology of occultHBVinfection as well as its diagnosis
and epidemiology, risk of transmission by blood transfusion
or liver transplantation, risk of reactivation in
conditions of immune suppression, its potential significance
in promoting the progression of chronic hepatitis
and thereby possible intervention strategies, and finally
its possible role in the development of hepatocellular carcinoma
(HCC). The final session of the meeting focused
on discussion among the members of the faculty that produced
a number of statements and recommendations that
are the subject of this report.