Almost 200 foodborne outbreaks affecting 800 people were reported in Hong Kong in 2019, according to a new report.

The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department and Department of Health are responsible for investigating and controlling food poisoning outbreaks related to local premises and businesses.

This past year, the CFS received 184 food poisoning outbreaks reported from the Department of Health, affecting 805 people.

The number of outbreaks has shown a decreasing trend during the past decade, although there was a slight rise in 2019. This increase was mainly because of a lapse in hygiene in a few incidents leading to more outbreaks and people affected.

Number of food poisoning outbreaks and people affected from 2009-2019.

CFS reported 158 foodborne outbreaks affecting 641 people from the Department of Health in 2018.

Bacterial foodborne agents remained the leading cause of all foodborne disease outbreaks in 2019. Salmonella was behind 58.5 percent of all bacterial cases, followed by Vibrio parahaemolyticus at 26.3 percent and then Bacillus cereus and Staphylococcus aureus both at 5.3 percent.

Viral causes accounted for around 9.2 percent of food poisoning outbreaks and norovirus was involved in most cases. Inadequate cooking, contamination by raw food and improper holding temperature were the most frequently identified contributing factors. Biochemical agents caused 1.6 percent of outbreaks and 0.5 percent were due to chemicals.

Outbreak example
In June 2019, there were 17 reported clusters of food poisoning outbreaks related to one restaurant, affecting 40 people. Salmonella Enteritidis was isolated from the stool and blood specimens of some victims in different clusters. Epidemiological investigation of the clusters suggested they were related to the consumption of undercooked scrambled eggs.

Investigations in the restaurants revealed a large amount of whisked eggs, around 360 of them, were prepared from unpasteurised eggs one day beforehand and stored in a refrigerator at 9 degrees C (48 degrees F). Eggs were inadequately heated to a semi-cooked condition on the next day and kept in a lukewarm water bath at 30 degrees C (86 degrees F) throughout business hours. When orders were made, no further reheating or cooking of the eggs was done before serving to customers.

Advice was given to food handlers and the premises was told to suspend sale of the items and do a thorough cleansing and disinfection. After irregularities were rectified no further outbreaks have been reported.

To prevent Salmonella infection, the advice is to thoroughly cook egg dishes and prepare scrambled eggs on a per-order basis, avoid keeping food for a prolonged period of time, use pooled eggs as soon as possible and avoid topping up. For preparation of dishes without heat treatment, the advice is to use pasteurized eggs.

Monitoring food alerts
In 2019, the CFS identified about 2,040 incidents from the Food Incidents Surveillance System (FISS), a tool used to monitor and review food alerts outside Hong Kong. About 400 of these related to undeclared allergens.

In response to issues that might have local impact, the CFS took actions including contacting authorities and traders, issuing local alerts to inform the public and the trade and collecting food samples for analysis. When affected products were available locally, the CFS might instruct the trade to stop sale and recall the items.

For incidents with local alerts issued, the hazards identified included microbiological such as Listeria, Salmonella and E. coli; chemical use of unauthorized or excessive preservatives, undeclared allergens; physical including foreign bodies, and other issues such as substandard qualities.

Food incidents related to microbiological and chemical hazards accounted for 37 percent and 36 percent respectively. A total of 24 percent were because of physical hazards and 3 percent were classified as others.

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