Occult hepatitis B virus infection among blood donors from the Brazilian Amazon: implications for transfusion policy

Abstract

Background Brazil requires the performance of both a test for hepatitis B surface antigen (HBsAg) and a test for antibodies to the core of hepatitis B for blood donor screening. Blood centres in regions of high HBV endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-HBc reactivity. We evaluated the potential infectivity of donations positive for anti-HBc in search of a rational approach for the handling of these collections. Study Design and Methods We tested anti-HBc reactive blood donations from the state of Amazonas for the presence of HBV DNA and for titres of anti-HBs. The study population consists of village-based donors from the interior of Amazonas state. Results Among 3600 donations, 799 were anti-HBc reactive (22·2%). We were able to perform real-time PCR for the HBV S gene on specimens from 291 of these donors. Eight of these samples were negative for HBsAg and positive for HBV DNA and were defined as occult B virus infections (2·7%). Six of those eight specimens had anti-HBs titres above 100 mIU/ml, indicating the concomitant presence of the virus with high antibody titres. Conclusion A small proportion of anti-HBc reactive donors carry HBV DNA and anti-HBs testing is not useful for predicting viremia on them. This finding indicates the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. Sensitive HBV DNA nucleic acid testing may provide another level of safety, allowing eventual use of anti-HBc reactive units in critical situations.

Occult hepatitis B among patients with chronic renal failure on hemodialysis from a capital city in northeast Brazil

“…Confirming this trend, absence or low prevalence of OHB has been the most commonly obtained result in Brazilian studies on different populations, ranging from 0% to 2.7% …”

Hepatitis B Surface Antigen Should Not Be the Only Sought Marker to Distinguish Blood Donors towards Hepatitis B Virus Infection in High Prevalence Area

“…The prevalence of occult hepatitis B infection (OBI) is highly variable since figures in the literature are ranged from 0 to 50% [1]. Coulibaly ML [2], Moresco M. Ndos S [3], Said ZN [4] and Oluyinka OO [5], in their studies, found that OBI's prevalence was respectively: -6.12% in a series of 147 haemodialysed patients; -2.7% samples were negative for HBsAg and positive for HBV DNA in 3600; -17% occult hepatitis B infection in blood donors; -17.2% occult hepatitis B infection in 3167 negative HBsAg donors.…”

Characterization of hepatitis B virus (HBV) preS/S gene mutations in blood donors with occult HBV infection in the Baoji area of North China

“…Among blood donors in recent years, the incidence of OBI has varied with the prevalence of HBV and public health conditions. Specifically, the OBI incidence was 1:27 (19 of 507 donors) in Nigeria, 1:450 (8 of 3600 donors) in the Brazilian Amazon, 1:2450 (163 of 399,326 donors) and 1:3239 (95 of 307,740 donors) at the Hong Kong Red Cross Blood Transfusion Service and Shenzhen Blood Center of South China, 1:19,130 (23 to 4.4 million donors) in the Netherlands, 1:14,903 (34 of 506,689 donors) in Spain, at least 1:2200 (548 of 1,205,796 donors) in a multicenter investigation in China, and 1:5045 (298 of 1,503,484 donors) in a worldwide, multicenter investigation . A recent survey conducted by the National Institute of Diagnostics and Vaccine Development in Infectious Diseases of China showed that the incidence of OBI in blood donors in South China was 1:631 (61 of 38,499 donors), and more than one‐half (34 of 61 donors) of the OBI blood samples harbored major hydrophilic region (MHR) mutations, which are associated with failure to detect HBsAg .…”