Improperly cleaned vomit, faecal bacteria and a cockroach infestation were among the hygiene lapses the authorities have found in their investigations into the recent food poisoning outbreaks caused by food prepared at Mandarin Orchard Singapore hotel, FoodTalks Caterer and Manufacturer and Tung Lok Millennium.
In a joint statement yesterday, the Ministry of Health, National Environment Agency (NEA) and Agri-Food and Veterinary Authority said they have completed investigations into the recent incidents and found no links between the three cases or to the outbreak traced to Spize at River Valley Road.
In the most recent outbreak, traced to a banquet kitchen at Mandarin Orchard, 315 people developed gastroenteritis symptoms after attending five separate events held at the 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.
Operations at the banquet kitchen serving the Grand Ballroom were suspended on Dec 5, and interviews with staff revealed 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 ballroom from poor environmental and personal hygiene practices, the authorities said.
Faecal coliform bacteria were detected in food samples and Bacillus cereus bacteria were found in various environmental swabs, such as those taken from the surfaces of utensils and door handles.
On Nov 26, 131 people were reported to have developed gastroenteritis symptoms after eating food prepared by FoodTalks during a pre-school day camp.
Investigations found several hygiene lapses and poor kitchen habits, including use of the same preparation table for raw food and ready-to-eat food items, and evidence of cockroach infestation.
While the exact cause could not be identified, the outbreak was likely due to ingestion of toxins produced by bacteria in the food, the authorities said.
In the third case, 190 people came down with 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, including lack of soap for handwashing.
Based on symptoms, the pathogen involved is unlikely to be related to any of the other three outbreaks, the statement said.
The suspension of Mandarin Orchard's banquet kitchen and 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 action against the licensees as well as FoodTalks for the lapses.
A Mandarin Orchard spokesman said in response to queries that the hotel has stopped the sale of several takeaway food items, including honey-glazed ham and roasted turkey, as they are prepared in the affected kitchen.