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HAV Foodborne Transmission Is Possible and Hazardous

Although the primary route of transmission of Hepatitis A (HAV) in the U.S. is person-to-person, foodborne transmission also is possible and has been linked to previous outbreaks. Recent cases in Europe have demonstrated this, with a July 2022 foodborne outbreak suspected to have a link to a restaurant in Hungary and officials in New Zealand investigating Hep A cases linked to berries having identified a connection with a past outbreak in Europe. These also follow a U.S. March/April HAV outbreak linked to fresh organic strawberries.

As indicated by the above noted foods, it is the contamination of ready-to-eat foods that is most probable, as transmission can arise from a lack of personal hygiene of employees, suppliers, or even customers. As we also stated in a recent public health article, the primary route of transmission in the U.S. is currently person-to-person, with certain groups at highest risk, including those who use drugs, are homeless, are men who have sex with men, are in jail or have chronic liver disease. But there is a risk that workers could be, or be exposed to, members of such groups or others in contact with them.

In a paper on foodborne transmission, CDC explains, “Transmission occurs by the fecal-oral route, either by direct contact with an HAV-infected person or by ingestion of HAV-contaminated food or water.” Although food- or waterborne outbreaks are relatively uncommon in the U.S., food handlers with hepatitis A are frequently identified, and “HAV-contaminated food may be the source of hepatitis A for an unknown proportion of persons whose source of infection is not identified.”

Additionally, the epidemiological and microbiological data of the recent spread of HAV in the UK and six EU countries, with more than 300 cases with identical or closely related HAV strains identified, suggest person-to-person transmission as well as the possible transmission through contaminated food. Following the July HAV foodborne outbreak with a suspected link to cold soup made with frozen berries in a Hungary restaurant; epidemiological investigation indicating possible foodborne infections in addition to person-to-person transmission in the UK outbreak; and cases in Germany, Sweden and the Netherlands matching the sequences of the UK strain, there’s little doubt that at least some of the transmission was foodborne.

This potential transmission provides one more reason for food businesses – from growers to foodservice and retailers – to ensure the personal hygiene of their workers and require it of suppliers, particularly for ready-to-eat foods. Thus, any supplier assessment should include surveillance around their management of human waste, handwashing practices, and location and availability of handwashing stations. At the other end of the spectrum, foodservice providers should not only ensure the personal hygiene of their workers, but should ensure the regular sanitation of restrooms as the virus could come into the restaurant through the restroom usage of an infected customer.

While practicing good hand hygiene plays an important role in preventing the spread of hepatitis A, surveillance to detect and investigate sporadic and clusters of cases is also essential. So possible food-borne transmission should be investigated when multiple cases are reported within a short period. This also goes beyond the personal hygiene contamination of food, as the containment of HAV transmission is further challenged by the fact that the virus is highly resistant to environmental conditions, acidification, and freezing.

Overall, TAG recommends food establishments have thorough supplier requirements that include assessment of handwashing facilities and general sanitation for both direct suppliers and supplier suppliers. Additionally, ensuring that restroom facilities are regularly maintained in a sanitary manner, particularly in food establishments that share restroom access with customers, is essential for viral containment. Incorporating practices that help to prevent the spread of HAV will have benefits for the containment of other infectious diseases as well, whether those have the potential for foodborne transmission or not.


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