**4. Concluding remarks**

Over the past few years, nucleic acid-based molecular methods have been developed, refined, and used for the detection of hNoVs and HAV that are most commonly associated with the transmission of foodborne viral disease. In particular, RT-qPCR has emerged as a preferred method for the detection and quantification of the viruses due to its high sensitivity, repro‐ ducibility, speed, and minimization of risk of carry-over contamination. Recent advances in high-throughput next-generation sequencing (NGS) technologies have opened new avenues for genomic research and diagnostic applications. It is expected that utilization of NGS in viral metagenomics and whole genome sequencing will highly improve the opportunities for identifying viruses of different origins including those that are too divergent to be detected by PCR or other molecular approaches. However, the identification of hNoVs and HAV in vast ranges of food matrices is still a demanding task that is largely attributed to some factors such as intrinsically low quantities of contaminated viruses and broad chemical composition of food, which may inhibit the activity of enzymes used in the molecular detection. This requires a meticulous investigation into sample preparation procedures to obtain acceptable recovery of viral RNA for downstream analysis. Nucleic acid-based molecular methods have a disad‐ vantage in that the majority of the reported assays for detection of foodborne virus contami‐ nation do not have standardized protocols, and can vary from laboratory to laboratory. This could be due to several reasons, such as different approaches required for preparation of viral nucleic acids from different test matrices, and a lack of multi-laboratory validation of prom‐ ising procedures. There is a need for harmonized standards and quality control of the reagents used. Moreover, in many cases, molecular methodology has focused on merely detecting the presence of viral nucleic acids that is not necessarily associated with the detection of infectious particles, although some studies stated above have shown promising differentiating results. Research on developing new methods to accurately determine the virus infectivity is eventu‐ ally needed to gauge health risk.
