Table 1.

Milestones in the progression of knowledge of occult HBV infection

Year—journal—authors	Topic
1975—Gastroenterology—Wands et al. [4]	OBI reactivation in patients undergoing chemotherapy
1978—N Engl J Med—Hoofnagle et al. [13]	HBV transmission by blood transfusion from an OBI donor
1981—N Engl J Med—Shafritz et al. [7]	HBV DNA integration in the hepatocyte genome of HBsAg-negative individuals
1981—Proc Natl Acad Sci—Brechot et al. [15]
1988—Lancet—Thiers et al. [6]	Acute hepatitis B in chimpanzees injected with HBV isolates from blood of OBI carriers
1989—Proc Natl Acad Sci—Kaneko et al. [12]	Polymerase chain reaction detection of HBV DNA in serum of HBsAg-negative individuals
1994—Lancet—Chazouillères et al. [14]	Liver transplant from OBI donors may induce hepatitis B in recipients
1994—J Clin Invest—Michalak et al. [11]	OBI in patients recovered from acute hepatitis B
1996—Nature Medicine—Rehermann et al. [8]	A strong CTL-specific anti-HBV response persists over time in patients who recovered from acute hepatitis B
1996—J Clin Invest—Penna et al. [10]
1999—N Engl J Med—Cacciola et al. [3]	OBI is associated with cirrhosis in patients with chronic hepatitis C and the virus is wild-type
2002—Lancet Inf Dis—Torbenson and Thomas [5]	First systematic review of the OBI field
2004—Gastroenterology—Pollicino et al. [9]	Molecular analyses of a large series of liver tumor tissues confirm the association between OBI and HCC
2008—J Hepatol—Raimondo et al. [2]	Statements on OBI by an international, large panel of experts