SINGAPORE: After a spate of high-profile food poisoning incidents in Singapore in recent weeks, people have been speculating about the possible causes and wondering how one can mitigate the risks.
The culprits behind severe food poisoning are likely to be bacteria transferred from a food handler’s hands, or things like vegetables not washed thoroughly enough, said infectious diseases expert Leong Hoe Nam.
Speaking to Channel NewsAsia following the recent cases - including one which turned fatal - he said that the bacteria found on hands typically do not grow a lot on their own.
“But when the bacteria come in touch with food, they will grow over four to six hours. They will over-proliferate because they feed on the food,” Dr Leong said. Toxins are produced in the process, he explained.
When food is left out in the open, or under low heat at about 30 to 40 degrees Celsius, it provides the perfect environment for this process, he added.
However, even when food has been contaminated with bacteria, its taste, smell and colour may not necessarily change, making the person consuming it none the wiser.
When the food is eaten along with the bacteria and toxins, it may cause food poisoning. But food poisoning, which doctors said is often interchangeably used with the term gastroenteritis, can also be caused by viral infections spread by people, and not just contaminated food.
The authorities have said they are investigating the recent cases that took place here.
In the first, one man died after consuming food from the River Valley outlet of Spize. In the second case, 190 people fell ill after eating food from TungLok’s catering arm. In yet another incident, more than 130 children and teachers at a kids' camp fell ill after consuming food prepared by caterer FoodTalks.
CROSS CONTAMINATION, FOOD SAFETY LAPSES TO BLAME AS WELL
Vegetables that are not washed properly could also be a reason for food poisoning, Dr Leong said. Vegetables are typically fertilised using manure, and the bacteria in the manure get eaten along with the vegetables when not washed properly, he explained.
If a knife used to cut dirty vegetables is used on other items, cross-contamination occurs, thus increasing the chances of food poisoning, he added.
Such lapses do not come as a surprise to food safety consultant Lawrence Low. In his 15 years of experience, he has seen knives stored in dirty gaps, dishwashers that are not hot enough to sanitise, and can openers that are not washed frequently enough.
"Detergent doesn't kill bacteria. Only sanitisers and hot water kill bacteria. If the dishwasher is not well-maintained, the bacteria may survive and grow," he said, adding that one of the issues could be the dishwasher not being hot enough.
He also shed some light on what could be going on in the minds of caterers. “If I only have enough resources to cook for up to 500 people, if I get an order for 900 people, do I reject it?” he asked rhetorically.
He said that in such situations, the company has to balance the need to fulfill orders keeping in mind the amount of resources they have.
This is because if there is a lack of resources, either in manpower or equipment, the food will have to be prepared earlier, he explained. Given the time lapse and improper storage of the food, bacteria may find their perfect home.
THE IMPORTANCE OF FOOD SAFETY KNOWLEDGE
Mr Low, however, said that Singapore has strict laws to ensure food safety. According to the National Environment Agency’s (NEA) website, all food handlers have to go for a basic food hygiene course. Course trainers said a certificate attained at the end of the one-day course lasts for five years, after which a refresher must be taken. The refresher lasts 10 years.
During the course, food handlers are educated on proper storage of foods, minimising the risks of food contamination and the importance of hand hygiene, among other things.
Dr Leong said that the certificate is “absolutely essential”. However, he said that while it provides knowledge, it will not stop a person who chooses to flout the law.
“Food hygiene is as good as the weakest link,” he said.
HOW FOOD POISONING AFFECTS THE BODY
While severe food poisoning can even lead to death, Dr Leong said that the body is able to cope with mild contamination.
Consultant in the Division of Gastroenterology and Hepatology at the National University Hospital Mark Muthiah said that most food poisoning cases “resolve spontaneously and do not need any specific treatment”.
Despite the recent death from food poisoning in Singapore, the illness is rarely fatal, Dr Muthiah said. He pointed out that in the United States, for instance, fewer than one out of every 15,000 patients with gastroenteritis dies from the disease.
Explaining how food poisoning affects a victim, Dr Muthiah said a viral or bacterial infection causes inflammation in the lining of the intestines, which leads to secretion of fluids within the intestines, as well as the inability to absorb fluids. The body tries to get rid of this, resulting in vomiting, diarrhoea or both.
HOW TO PREVENT AND MINIMISE THE RISK OF FOOD POISONING
Specialist in Emergency Medicine at the Raffles Emergency Department Dr Goh E Shaun suggested that people consume foods from trusted restaurants or stalls, and to pay heed to cleanliness standards ratings issued by the NEA.
Consumers can also do some research before ordering from a caterer, said Mr Low, but making an informed judgment could still prove challenging. While retail food establishments are required to display their hygiene standards rating from the NEA prominently, it is more difficult to find the rating of a company that does only catering.
Associate Professor Hsu Li Yang who heads the Infectious Diseases Programme at the National University of Singapore’s Saw Swee Hock School of Public Health said it is “very difficult” to detect contaminated food.
“Obviously not continuing to eat food that tastes 'off', or consuming food that is past the expiry date or time, will help. When in doubt, toss away the food,” he said.
The elderly or the very young, as well as those with compromised immune systems, may fare worse when hit by either viral gastroenteritis or food poisoning, he added.
“For those who are afflicted by the stomach flu or food poisoning, the key is to ensure adequate fluid intake, which can include water, soup, as well as other oral rehydration solutions,” he said.