Researchers are raising concerns about the spread of Hepatitis A virus (HAV) through shellfish in the Philippines, urging more research and stricter monitoring measures. Experts from Ateneo de Manila University, the University of the Philippines, Monash University Malaysia, and the Bureau of Fisheries and Aquatic Resources caution that the risks associated with HAV remain poorly understood, despite the popularity of locally farmed oysters and mussels.
Although Filipinos are familiar with seafood hazards like “red tide,” awareness about viral contamination, including HAV, remains low. HAV can spread through food and water contaminated by fecal matter, with improperly prepared shellfish posing a particular risk. As filter feeders, oysters and mussels absorb pollutants from surrounding waters, increasing the likelihood of harbouring viruses. Once inside these shellfish, the virus can remain viable for up to ten weeks, significantly raising the chances of transmission.
The supply chain offers multiple points for contamination, from the farms where shellfish are cultivated to household cooking practices. Farms are often situated in coastal areas near industrial or residential zones prone to pollution. Additionally, little is known about whether traditional cooking methods like boiling or steaming are effective in eliminating HAV, leaving gaps in food safety practices.
At present, the Philippines focuses on testing for bacterial pathogens such as E. coli and salmonella to assess shellfish safety. However, these tests do not detect HAV or other viruses, creating blind spots in monitoring efforts. The absence of a consistent surveillance program for HAV in shellfish or the environment further limits the country’s ability to detect potential outbreaks.
Researchers stress the need for deeper investigation into the “farm-to-fork” journey of shellfish and more targeted public awareness campaigns to address the risks posed by viral contamination. They also recommend the implementation of dedicated monitoring programs to better safeguard public health and prevent future outbreaks.
