Posted 18 August 2016
By Michael Mezher
The US Food and Drug Administration (FDA) on Wednesday finalized its guidance on reducing the risk of hepatitis B virus (HBV) transmission via human cells, tissues and cellular and tissue-based products (HCT/Ps) by screening donors with nucleic acid tests (NAT).
Specifically, FDA says that HCT/P establishments should add nucleic acid tests for HBV to their testing arsenal as the new tests offer significant improvements in how early the virus can be detected.
"FDA-licensed HBV NAT can detect evidence of the viral infection at an earlier stage than the hepatitis B surface antigen (HBsAg) and total antibody to hepatitis B core antigen (anti-HBc tests). Therefore, we recommend the use of FDA-licensed HBV NAT, in addition to the use of licensed HBsAg and total HBc Immunoglobulin G (IgB) and Immunoglobulin M (IgM), for testing donors of HCT/Ps for evidence of infection with HBV," the final guidance says.
The US Centers for Disease Control and Prevention (CDC) estimates there were roughly 20,000 HBV infections in the US in 2013, with as many as 1.4 million people living with the disease. And, while most adults infected with the virus will clear the disease, between 30 and 90%of children under five will develop a chronic infection.
According to FDA, the recommendation to add nucleic acid tests to existing donor-screening methods is necessary as the disease is "transmitted by blood transfusions more frequently than hepatitis C virus (HCV) or human immunodeficiency virus (HIV)," and has been documented to spread by tissue transplantation.
The agency goes on to say that nucleic acid tests offer a potential 40-day reduction in how soon the virus can be detected compared to HBsAg tests, and have a higher likelihood of detecting new mutations of the virus.
As such, FDA says that HCT/P facilities should begin screening with all three assay types (HBV NAT, HBsAg, and anti-HBc IgG/IgM) within the next six months, and only accept donors who test negative for HBV with all three tests.