SINGAPORE - There are no links between the string of food poisoning outbreaks at Mandarin Orchard Hotel, FoodTalks Caterer and Manufacturer, Tung Lok Millennium and Spize Restaurant at River Valley Road, the authorities said on Friday (Dec 14).

In a joint statement, the Ministry of Health (MOH), National Environment Agency (NEA) and Agri-Food and Veterinary Authority (AVA) said they have completed investigations into the recent gastroenteritis incidents and found no links based on epidemiological findings, clinical presentation and laboratory findings.

In the most recent outbreak traced to a banquet kitchen at Mandarin Orchard Hotel, a total of 315 cases were reported in which people developed gastroenteritis symptoms after attending five separate events held at its grand ballroom between Dec 1 and 3.

Thirteen of the 14 hospitalised patients have since been discharged, while the remaining patient's condition is stable, the authorities said in an update.

The banquet kitchen serving the grand ballroom was suspended on Dec 5, and interviews with staff revealed that there was "improper cleaning of vomitus in the Grand Ballroom, and banquet servers had continued to work while ill".

Investigations suggest an outbreak of norovirus gastroenteritis, as there is strong evidence of "severe contamination" of the grand ballroom from poor environmental and personal hygiene practices, the authorities said.

Norovirus was detected from the stool samples collected from five attendees, three food handlers and 28 service staff, including banquet servers who reported to have continued working while they were ill.

Environmental swabs collected from the grand ballroom also detected norovirus from environmental surfaces such as carpet, tables, chairs, unused table cloths, cutlery and drinking glasses. Faecal coliform bacteria were detected in food samples and Bacillus cereus bacteria from various environmental swabs, such as those taken from the surfaces of utensils and door handles.

Related Story Spize in River Valley to shut, face charges over lapses

Related Story NEA suspends licence of TungLok Catering after 190 at SCDF event fall ill

Related Story 131 people down with gastroenteritis after consuming food from FoodTalks

Norovirus is a common virus that causes gastroenteritis and can spread easily from contaminated food or surfaces.

In the second case, 131 people including Kindergarten 2 children and teachers were reported to have developed gastroenteritis symptoms after eating food prepared by FoodTalks Caterer and Manufacturer in Bedok North during a pre-school day camp on Nov 26.

Investigations of the caterer found several hygiene lapses and poor kitchen habits, including the lack of proper segregation between raw and ready-to-eat food in the same chiller compartment, use of the same preparation table for raw food and ready-to-eat food items, evidence of cockroach infestation and preparation of ready-to-eat food items one to two days before consumption.

While the exact cause could not be identified, the short incubation period from consumption of the food to development of symptoms and predominant symptom of vomiting suggest that the outbreak was likely due to ingestion of toxins produced by bacteria in the food, the authorities said.

In the third case, 190 people were reported to have developed gastroenteritis symptoms after consuming food prepared by Tung Lok Millennium at an event at the Singapore Expo held between Nov 19 and 21.

The caterer's operating licence was suspended on Nov 23 after an inspection found several hygiene lapses and poor kitchen habits, including lack of soap for handwashing. An environmental swab taken from the bento packing table also tested positive for Bacilus cereus bacteria.

As most of the people affected had recovered by the time MOH was informed of the outbreak, stool samples were not available for analysis. But based on symptoms, the pathogen involved is unlikely to be related to any of other three outbreaks reported, the statement said.

The suspension of the banquet kitchen at Mandarin Orchard Hotel, the closure of its grand ballroom and the suspension of Tung Lok Millennium will remain in place until NEA is satisfied that public health risks have been addressed, the authorities said.

NEA will also be taking enforcement actions against the licensees as well as FoodTalks for the lapses.

A spokesman for Mandarin Orchard said in response to queries on Friday that it has stopped the sale of several takeaway food items for the festive season, including its honey-glazed ham and roasted turkey, as roast items from its Christmas Takeaway selection are prepared in the affected banquet kitchen.

Customers who had placed their orders for these items have been contacted and "assisted accordingly", the spokesman said.

"We remain committed to adhering to stringent food hygiene and sanitation standards across our food and beverage operations," she said.