Summary
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Hepatitis A is a liver inflammation caused by the hepatitis A virus (HAV), which is transmitted primarily by the faecal-oral route. In other words, a person who has never been infected or vaccinated is infected through ingestion of food or drinks that have been contaminated with the faeces of an infected person, or through close and personal contact with an infected person;
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Typical clinical symptoms include fever, nausea, loss of appetite, vomiting, diarrhoea, dark-coloured urine, jaundice, etc. However, not all infected persons manifest symptoms; for instance, infected children under 5 years of age are usually asymptomatic. Most people infected with hepatitis A can make a full recovery. In rare cases, hepatitis A can cause liver failure and even death;
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Food is one of the major transmission media of hepatitis A. The transmission channel is mainly due to people’s ingestion of undercooked food, ice cubes or drinking water contaminated with HAV. Though the virus is highly transmissible, it can be destroyed by cooking food to an internal temperature of 90°C for over 90 seconds;
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The public should purchase food ingredients from reliable shops in good hygiene condition. Do not purchase food ingredients from unknown sources or those that have not been subject to inspection and quarantine. Observe good personal, food and environmental hygiene at all times and cook food thoroughly before eating. In case of feeling unwell, such as experiencing diarrhoea, vomiting, fever or jaundice, refrain from handling food.
Introduction
In March 2023, the United States Food and Drug Administration announced that it was in the course of investigation of a number of cases involving residents in many states suspected of hepatitis A infection due to consumption of frozen berry products. As a consequence, the local food trade recalled multiple frozen berry products that may have been contaminated with HAV. The incident has also caused the food trade of neighbouring regions of Macao to carry out extensive food recalls, raising much public concern.
About Hepatitis A
Hepatitis A is a liver inflammation caused by the hepatitis A virus (HAV), with typical clinical symptoms including fever, nausea, loss of appetite, vomiting, diarrhoea, dark-coloured urine, jaundice, etc. However, not all infected persons manifest symptoms; for instance, infected children under 5 years of age are usually asymptomatic. Most people infected with hepatitis A can make a full recovery. In rare cases, hepatitis A can cause liver failure and even death. The virus can be found in the faeces and blood of infected persons, and is transmitted primarily by the faecal-oral route. In other words, a person who has never been infected or vaccinated is infected through ingestion of food or drinks that have been contaminated with the faeces of an infected person, or through close and personal contact with an infected person. The incubation period is generally between 15 and 50 days, with an average of 28 to 30 days.
Hepatitis A and Food Safety
Food is one of the primary transmission media of hepatitis A. The transmission channel is mainly due to people’s ingestion of undercooked food, ice cubes or drinking water that has been contaminated with HAV. Though the virus is highly transmissible, it can be readily destroyed by cooking food to an internal temperature of 90°C for over 90 seconds.
According to available data, fruits, vegetables and bivalve aquatic animals are the most common food susceptible to HAV contamination. During cultivation, fruits and vegetables can be contaminated with HAV if the water sources used for irrigation, processing or washing are HAV-contaminated. Bivalve aquatic animals (e.g. oysters, geoducks, clams, razor clams, mussels and scallops) are filter feeders that feed by filtering fine organic particles from the water. If the water body inhabited by the bivalve aquatic animals contains HAV, the virus may accumulate in the bivalves’ body. Humans can be infected with hepatitis A when they eat these raw or undercooked fruits, vegetables and bivalve aquatic animals.
In addition, if a hepatitis A-infected food handler fails to observe good personal, food and environmental hygiene practices during food production and operation, the food products and related utensils may be contaminated with HAV. People may develop hepatitis A after eating these contaminated food products. Therefore, maintaining good personal, food and environmental hygiene at all times can help to prevent hepatitis A infection.
Regulations in Macao
IAM has been overseeing the safety of commercially available food products in Macao through Routine Food Surveillance, Seasonal Food Surveillance, Targeted Food Surveillance and the Food Incident Monitoring System. It takes immediate actions, according to the degree and extent of risks, so as to control the spread of the risks. In addition to sending food alerts to food importers and retailers concerned, IAM orders them to recall all the problematic food products available in Macao, and releases respective information to notify the public and the trade in a timely manner to safeguard food safety in Macao.
In light of the aforementioned incident in the United States that some members of the public were suspected of hepatitis A infection through consumption of frozen berry products, IAM has promptly investigated into the distribution of the affected food products in the local market and taken follow-up actions to ensure the safety of food products available in the market. The relevant information was conveyed to the food trade and uploaded to the designated webpage on “International News” of “Food Safety Information” website for the reference of the food trade and the public.
Advice to the trade and the public
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Always buy food ingredients from reliable shops in good hygiene condition, and never buy food ingredients of unknown origin or that have not been subject to mandatory inspection and quarantine;
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Maintain good personal hygiene practices, such as wash hands properly and thoroughly before eating and handling food, and after using the toilet;
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Wash food ingredients with clean and hygienic water;
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Use different sets of utensils to handle raw food and cooked or ready-to-eat food separately to avoid cross-contamination;
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Wrap food properly or keep it in covered containers for storage in the refrigerator, and observe the principle of “storing cooked food above raw food”;
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Cook food ingredients thoroughly to reach an internal temperature of 90°C for over 90 seconds, which can readily destroy the hepatitis A virus in food;
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In case of diarrhoea, vomiting, fever, jaundice or experiencing other physical discomforts, refrain from handling food;
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Food production and operation establishments should make arrangements for their food handlers to receive appropriate training, and ensure that they have full knowledge and understanding of the hygiene requirements for handling food.
References:
1. Hepatitis A (World Health Organization), 20 July 2022
https://www.who.int/news-room/fact-sheets/detail/hepatitis-a
2. Outbreak Investigation of Hepatitis A Virus Infections: Frozen Strawberries (US FDA), 15 September 2023
3. Guidelines on the Application of General Principles of Food Hygiene to the Control of Viruses in Food, CAC/GL 79-2012 (Codex Alimentarius Commission), 2012
4. Hepatitis A and Frozen Strawberries (Centre for Food Safety of Hong Kong), 21 June 2023
https://www.cfs.gov.hk/tc_chi/multimedia/multimedia_pub/multimedia_pub_fsf_203_02.html
5. Hepatitis A Virus in Shellfish (Centre for Food Safety of Hong Kong), 28 June 2019
https://www.cfs.gov.hk/tc_chi/programme/programme_rafs/programme_rafs_fm_02_06.html
BRR 008 DAR 2023
