The paper by Candotti et al. describes HBV transmission to 9 (nine) recipients by blood transfusion with FFP and RBC components from 3 (three) Slovenian blood donors with occult hepatitis B infection (OBI). The viruses remained undetected by both serology (HBsAg) and NAT testing.
The paper states that this observation suggests a need to reconsider the minimal HBV infectious dose and the NAT sensitivity required to prevent HBV transmission by transfusion. The study found that a HBV transfusion transmission from occult HBV infection carrying extremely low viral load was correlated with the plasma volume transfused.
The authors conclude that HBV blood safety could be further improved by either anti-HBc screening, HBV NAT with an LOD of 0.8 copies/ml (0.15 iU/ml) or pathogen reduction of blood components. The latter recommendation was derived from the observation that none of the (6) six recipients receiving INTERCEPT™ treated platelet concentrates were infected.
The paper indicates that OBI has been described as a threat to transfusion of blood components in several countries and the applied testing systems were shown to be insufficient to prevent transmissions whereas pathogen reduction with amotosalen and UVA light has demonstrated its high degree of efficiency.
Reference: Candotti D, et al. Gut 2018;0:1–9. doi:10.1136/gutjnl-2018-316490
https://gut.bmj.com/content/early/2018/06/29/gutjnl-2018-316490