International Forum on Occult hepatitis B infection and transfusion safety

Abstract

Anti-HBc testing is mandatory in France since 1988 and contributes to prevent occult HBV infection. Reference 1 Assal A, Barlet V, Deschaseaux M, Dupont I, Gallian P, Guitton C, Morel P, David B, De Micco P: Comparison of the analytical and operational performance of two viral nucleic acid test blood screening systems: Procleix Tigris and cobas s 201. Question 1Investigating archive samples for HBV DNA reactive/ HBsAg non-reactive duration, we found that only about 15% of the samples investigated had a duration of less than 60 days. Meaning that in only 15% of the samples with the HBV DNA +/HBsAgresult pattern, window period could not be excluded. Therefore, majority of our NAT yield cases are OBI cases as defined by the

Occult and active hepatitis B virus detection in donated blood in São Paulo, Brazil

“…In an international forum, OBI prevalence among 10 blood banks ranged between 1:14,000 donations in Spain and 1: 871,000 donations in the United Kingdom. In Brazil, the rate was 1:30,048 donations, 12 which was similar to our present finding of 1: 33,060 donations. In the USA, OBI ranged between 1.7 and 2.2 per 100,000 donations.…”

“…This is especially a problem in medium‐high prevalence countries where HBcAb testing is not part of the screening protocol due to the high rate of donor blood disposal. In low‐endemic countries where HBV NAT was implemented, the residual risk assessed after NAT was considered tolerable and, therefore, the addition of HBcAb testing was deemed to not be cost effective 12 …”

“…In low-endemic countries where HBV NAT was implemented, the residual risk assessed after NAT was considered tolerable and, therefore, the addition of HBcAb testing was deemed to not be cost effective. 12 OBI is characterized by the presence of HBV in hepatocytes under conditions where plasma viremia is generally intermittently present and quite low (<200 IU/ml). In addition, HBsAg is undetected in blood, with or without the presence of antibodies to HBV surface antigen (HBsAb).…”

Occult hepatitis B infection and hepatocellular carcinoma: Epidemiology, virology, hepatocarcinogenesis and clinical significance

“…Since transfusion is a major route of transmission in developing and resource-poor countries, 23 it is reasonable to examine the global prevalence of OBI and transfusion safety, as reviewed by Clive R. Seed and an assembly of international experts. 24 In this forum, a recent multicentre survey of almost 11 million donations worldwide found lower OBI NAT yield rates that varied from 1 in 3,900 to 1 in 59,000, with even higher rates of 1 in 1,000 donations found in regions where genotypes B, C or E prevail (Asia and Western Africa). 25,26 As previously discussed, detection of OBI is directly correlated with increased anti-HBc reactivity which also correlates with the level of cccDNA.…”

Blood donor screening in the Netherlands: Universal anti‐HBc screening in combination with HBV nucleic acid amplification testing may allow discontinuation of hepatitis B virus antigen testing

“…3,4 Occult HBV infection (OBI) is defined as chronic HBV infection in the absence of detectable HBsAg, and is characterized by (very) low, often intermittent viremia. 5 The minimal infectious dose of HBV is estimated to be as low as 3 IU. 6 In the Netherlands, the typical plasma volume per unit red blood cell concentrate or thrombocyte concentrate is 5-10 mL and 50-150 mL, respectively.…”