Hepatitis B Virus (HBV) - donors with occult HBV infection

Ready to upload
Record number: 
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
Only the recipient of plasma, and not the recipients of platelets and red blood cell components became infected, influenced by the larger infectious dose present. There are various parameters that influence the rate of transmission of occult hepatitis B virus infection (OBI); Seed et al (see reference) describe the calculated infectivity and estimate transmission rates.
Time to detection: 
5 to 7 months from transfusion of plasma, through a look back exercise.
Alerting signals, symptoms, evidence of occurrence: 
Repeat donor who tested negative for HBsAg and HBV DNA at the time of the index donation. Plasma, platelets and red blood cell components were made and transfused. Seven months later the donor returned to donate and was found to be HBV DNA positive, with a viral load of 57 IU/ml. HBsAg negative, anti-HBsAg 55 IU/ml, anti-HBcore total and anti-HBeAg positive; anti-core IgM negative, HBeAg negative. The recipients of the 3 components made from the previous donation were traced back and tested. The recipient of plasma was undergoing chemotherapy at the time of the implicated transfusion and was found to be asymptomatically infected with HBV, with a plasma viral load of 3380 IU/ml, when tested 7 months post transfusion. The platelet recipient was negative for HBV but had demonstrable boost in anti-HBsAg levels, suggesting exposure to the virus. The red blood cell recipient did not have demonstrable HBV infection. The inability of the assay used, to detect HBsAg in this case is linked to the mutations mapping to the major hydrophilic region of the dominant antigenic region of the surface antigen.
Demonstration of imputability or root cause: 
The recipient did not have serological evidence of previous exposure to HBV prior to the transfusion. The HBV strain from donor and recipient were of the same genotype D, with identical nucleotide sequence across the pre S /S region of the viral genome. Sequences from unrelated HBV strains were not produced for comparison.
Imputability grade: 
3 Definite/Certain/Proven
Suggest new keywords: 
Hepatits B virus
Occult HBV Infection
transfusion-associated infection
Suggest references: 
- Infectivity of blood components from donors with occult hepatitis B infection - results from an Australian lookback programme. Seed CR et al. Vox Sang. 2015 Feb;108(2):113-22. - HBV transmission from an occult carrier with five mutations in the major hydrophilic region of HBsAg to an immunosuppressed plasma recipient. Coppola N et al. J Clin Virol. 58(1):315-7, 2013 Sep. - Occult hepatitis B virus infection as a cause of posttransfusion hepatitis in patients with cancers. Sodhi JS et al. Indian J Gastroenterol. 32(5):291-6, 2013 Sep.
Expert comments for publication: 
This paper describes a HBV surface antigen variant which led to HBsAg detection failure by the serological assay used. Due to the low level of virus present, only the plasma recipient became infected.