Development of a new concentration method for Hepatitis A virus detection (ISO 15216–2:2019) in Manila clams (Ruditapes philippinarum)

Abstract

Hepatitis A virus (HAV) is an important agent of foodborne human viral illness and continues to be a public health concern. Currently, the RT-qPCR method (ISO 15216–2:2019) is the gold standard for HAV detection in food. However, because of the complex food matrix and low virus titers in food, there is a need for effective methods for virus enrichment. In this study, we developed a sensitive method for HAV detection in Manila clams and added polyethylene glycol (PEG) precipitation procedures on the ISO 15216–2:2019 standard method (SM). The results showed that the recovery rates were significantly higher with more process control virus (MS2) added in the improved method (IM) than in SM, from 0.24% to 1.34% and 3.22%–13.91% respectively. The detection sensitivity of the new method (101.5 CCID50/mL) in IM was lower than that of the standard method (102.5 CCID50/mL) in SM, with recovery rates of 6.38% and 2.45%, respectively. The positive detection rate of HAV (4.48%) in IM was significantly higher than that in the standard method (0.75%). The new method is a rapid and suitable method for concentrating and detecting HAV from Manila clams. This approach has important applications in HAV monitoring and detection to ensure the safety of Manila clams for human consumption.