The Nigerian Institute of Medical Research (NIMR) has raised new concerns about the safety of blood transfusions across the country following fresh findings on a largely undetected form of Hepatitis B infection.
A research fellow at NIMR’s Centre for Infectious Diseases and Research, Ms Oluwatoyin Awoderu, disclosed during a recent press briefing that the condition, known as Occult Hepatitis B Infection (OBI), poses a serious but overlooked threat to Nigeria’s blood supply system.
OBI is a chronic form of Hepatitis B in which the virus’s DNA is present in the liver and sometimes in the blood, but the Hepatitis B surface antigen (HBsAg), the standard marker used in routine tests, is not detectable. This makes it difficult to identify infected donors through conventional screening.
According to Awoderu, the infection can be transmitted through blood transfusions and organ transplants, and may progress to Hepatocellular Carcinoma (HCC) or reactivate in immunocompromised individuals, such as those undergoing chemotherapy or living with HIV.
“We discovered a group of individuals who tested negative for the Hepatitis B surface antigen, which is what is used in routine screening, but still carried the virus. These are what we call occult Hepatitis B cases,” she said.
Despite sustained efforts to curb Hepatitis B, Awoderu noted that Nigeria has remained endemic for over six decades, prompting researchers to investigate hidden drivers of its persistence.
As part of the NIMR study, blood samples were collected from apparently healthy individuals across several states and screened for multiple Hepatitis B biomarkers beyond the standard surface antigen test.
The team identified a small but significant subset of individuals who harboured the virus without showing up positive on regular screening. While the group represents less than one per cent of those tested, Awoderu warned that their presence within the blood donation system could have serious public health consequences, especially for newborns and immunocompromised patients.
“Blood from these occult carriers may be wrongly classified as safe and used for transfusion or transplant. This poses a high risk, particularly to neonates, about seven to eight per cent of whom receive transfusions yearly. If exposed to occult Hepatitis B, they could develop chronic infection that lasts a lifetime,” she cautioned.
Awoderu explained that Nigeria’s current blood screening protocols focus solely on detecting the surface antigen, which, although standard practice, fails to capture OBI cases.
“This group can only be identified through more advanced testing or liver biopsy, which is not routinely performed in our healthcare system. If such blood is given to a susceptible individual, especially one who is immunosuppressed, the virus can reactivate,” she added.
The researcher therefore called for urgent reforms in national blood safety policies, urging authorities to integrate broader Hepatitis B testing that includes multiple biomarkers to prevent hidden infections from slipping through.
“Before any blood or organ is released for use, comprehensive screening must be done to ensure it does not pose hidden risks. Occult Hepatitis B is real and present in our communities,” Awoderu warned.
