Experts have named norovirus the leading cause of viral foodborne illness, followed by Hepatitis A and Hepatitis E.

Hepatitis A and E viruses were ranked equally but higher compared to norovirus in terms of clinical severity by scientists at a recent meeting organized by the World Health Organization (WHO) and the UN Food and Agriculture Organization (FAO).

In September, the Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment (JEMRA) on viruses in foods took place in Rome, Italy, in response to a request by the Codex Committee on Food Hygiene in 2022.

It focused on food attribution, analytical methods, and indicators. A summary of findings has been published, with the full report available later.

Scientists reviewed the literature on foodborne viruses published since the 2008 JEMRA report on the topic and information submitted in response to a call for data.

Virus and food combinations
Foodborne viruses were ranked according to frequency and severity and in terms of the type of foods linked to the biggest public health concern.

The virus-commodity pairs associated with the highest global public health burden included prepared food, frozen berries, and shellfish for norovirus. For Hepatitis A, it was the same foods but in a different order, with shellfish first and prepared foods third. For Hepatitis E, pork was top, followed by wild game. However, scientists said there were considerable regional differences.

There was a lack of data to rank foods contaminated by astrovirus, sapovirus, enterovirus, enteric adenovirus, and rotavirus. Scientists said countries should enhance investigations of foodborne illnesses and foods for these viruses.

Annually, norovirus is estimated to cause 125 million cases of foodborne illness and 35,000 deaths globally.

Hepatitis A virus is believed to be behind 14 million cases and 28,000 deaths annually and is a reportable disease in some countries. For Hepatitis E, no global estimate of cases attributed to food exists.

Experts also discussed methods for virus testing in outbreak investigations and product testing as part of surveillance and monitoring strategies.

International Organization for Standardization (ISO) methods are widely used to detect norovirus and Hepatitis A viruses in various commodities. Methods for Hepatitis E virus detection in meat products are under development.

Current standardized methods are based on detecting viral nucleic acid, which does not necessarily indicate infectivity. Methods can be limited by factors such as the complexity of the food and low levels of contamination. Research on indicators for viral contamination is also needed.

Experts recommended that countries consider capacity building to support training and adopting methods for detecting viruses in foods and the environment.

“This approach has the potential to enhance knowledge on food attribution, support risk analysis, and reduce the burden of viral foodborne disease worldwide,” they said.

IAEA and FAO program
Meanwhile, the International Atomic Energy Agency (IAEA) and FAO have created a new initiative. 

Atoms4Food will support countries to use nuclear techniques to enhance agricultural productivity, reduce food losses, ensure food safety, improve nutrition, and adapt to the challenges of climate change.

Nuclear techniques can be used in different ways as part of food security. Irradiation can play a part in ensuring that food is safe from pathogens and to increase shelf life.

Through the initiative, IAEA and FAO will help in seven areas, including a food safety and control service, to make individual assessments of a country’s laboratory capabilities and ability to conduct surveillance of food hazards.