Blueberries and other berries are often touted as superfoods packed with antioxidants and nutrients. However, according to a recent article on idse.net, these popular fruits can also harbor a serious and underrecognized threat – hepatitis A virus. Multiple multistate outbreaks of hepatitis A infections have been traced back to fresh and frozen berry products in recent years, highlighting an urgent need for improved detection methods.
Researcher Mathilde Trudel-Ferland, PhD, from the Department of Animal and Food Sciences at the University of Delaware, shed light on the difficulties in identifying hepatitis A contamination in berry shipments. Despite the FDA conducting microbiological surveillance, current testing protocols are laborious, expensive, and time-consuming. Between 2019 and 2023, the agency discovered 9 positive samples among 1,513 frozen berry batches tested, leading to product recalls – even though no associated illnesses were reported.
A major challenge is that hepatitis A found in food sources typically cannot be cultured, or grown in a lab for testing. Non-clinical samples also often contain extremely low viral concentrations, further complicating detection. Trudel-Ferland emphasized the importance of establishing standardized methods to limit foodborne illnesses and reduce the staggering economic costs of associated food waste.
Two primary detection techniques are currently employed – the International Organization Standard ISO 15216-2:2019 and the FDA’s Bacteriological Analytical Manual chapter 26 (BAM 26) method. In a comparative study, Trudel-Ferland’s team found that while the ISO protocol detected hepatitis A in 2 out of 3 frozen strawberry samples at low viral loads, the BAM 26 method identified all 3 positive samples.
However, both tests are qualitative rather than quantitative, and a larger sample size is needed to draw definitive conclusions. Additionally, these analyses can take over 24 hours, with the ISO method being highly labor-intensive and the BAM 26 costly and unavailable in many labs – making them ill-suited for routine viral screening.
To address these limitations, Trudel-Ferland is exploring an automated nucleic acid extraction platform to streamline hepatitis A detection in berries. As she notes, implementing robust and widely accessible testing is crucial to curbing foodborne viral outbreaks while minimizing unnecessary economic losses from product recalls when no infectious pathogens are present.
Proactively safeguarding the berry supply chain from hepatitis A and other viral contaminants is an increasingly important food safety priority demanding innovative solutions. Raising industry standards and technological capabilities in this area could prevent many future health scares.
Commenting on this story, one national food safety attorney said, “Many consumers enjoy frozen berries as part of their diet. Uncovering new hepatitis A detection methods is a critical component to help safeguard our food supply and public safety.”
