Assessing the incidence of enteric viruses in bivalve mollusks at Alexandria's seafood markets

Abstract

This study investigates the presence of enteric RNA viruses, specifically hepatitis A virus (HAV), noroviruses, and rotaviruses, in bivalve mollusks sourced from two seafood markets in Alexandria City, Egypt. Given the escalating concerns regarding food safety—particularly related to the raw consumption of shellfish in regions with high shellfish consumption—this research addresses the critical problem of viral contamination in local bivalve species. A total of 72 samples were analyzed using quantitative reverse transcription polymerase chain reaction (qRT-PCR), revealing that 27 samples (37.5 %) tested positive for at least one virus. Notably, HAV prevalence was found to be 15.2 %, exceeding rates reported in other Mediterranean cohorts. Additionally, norovirus (12.5 %) and rotavirus (9.7 %) exhibited seasonal peaks during the winter and fall, consistent with global trends of viral persistence in marine aerosols. The quantified viral loads ranged from 10² to 10⁵ copies/g, surpassing known minimum infectious doses (10–100 particles), thereby confirming significant risks to consumers from the consumption of raw shellfish. This finding highlights the potentially serious hepatitis risk to consumers, especially shellfish are frequently consumed raw. These data underscore the necessity of consumer education programs to encourage individuals to avoid the consumption of raw shellfish. These findings underscore the urgent need for Egypt to implement routine monitoring of seafood viromes and improve sanitation infrastructure, aligning with the United Nations Sustainable Development Goals. This study not only enhances our understanding of viral contamination in seafood but also provides essential data to inform public health policies and promote food safety in Egypt. The implications of these findings are vital for safeguarding public health and ensuring the well-being of consumers in the region.