Sales of yusheng, a raw fish dish, have taken a hit after news broke that two types of fish were found to have traces of a bacterium that can cause infections of the skin, joints, heart and brain.
Hawkers told The Straits Times that consumers are spooked and are avoiding the dish even if it is made from other types of fish with no links to the Group B Streptococcus (GBS) bacterium.
The National Environment Agency (NEA) has asked more than 70 raw fish porridge stalls to temporarily stop selling raw fish dishes made from Song fish, also known as Asian Bighead Carp, and Toman fish, also known as Snakehead.
The yusheng sold at hawker centres consists of thinly sliced strips of raw fish mixed in sesame oil and topped with ginger and chilli.
Maxwell Food Centre's Zhen Zhen Porridge, famed for its Song-fish yusheng, has stopped selling it for now. This, coupled with renovation near the food centre, has caused business to fall by 20 per cent, said owner Kiang Joon Chin, 60. About half of the 40kg to 50kg of Song fish he used to order daily were sold as yusheng. He has cut his supply to about 20kg and sells the fish fully cooked in porridge.
The Ministry of Health (MOH) said in a statement last Friday that it had found a link between the consumption of raw fish and GBS infection in a "limited number" of cases. It is carrying out further studies before reaching a definite conclusion.
Public hospitals have seen 238 cases of GBS infection in the first half of the year, up from an average of 150 cases in the last four years.
GBS is a common bacterium found in the gut and urinary tract of about 15 to 30 per cent of adults without causing disease. But it may occasionally cause infections of the skin, joints, heart and brain.
GBS does not pose a problem if the fish is well-cooked, said the joint statement by MOH, NEA and the Agri-Food and Veterinary Authority of Singapore (AVA).
Yusheng lovers can still get their fix at Amoy Street Food Centre's Soon Heng Pork & Fish Porridge and Tiong Bahru Market and Food Centre's Hwa Yuen Porridge stalls.
Both use the ikan parang - also known as wolf herring - which is pricier than the Song fish.
At Soon Heng, the smallest serving of raw fish costs $5, compared to $3 for the Song fish version.
Hwa Yuen's second-generation owner Clement Yip, who is in his 60s, said: "We used to sell more than 100 servings a day. Now, not even 50. Nobody dares to eat raw fish now."
Soon Heng's owner, Mr Kiang Choon Tong, 68, used to sell more than 50 plates of raw ikan parang daily but that has fallen to 10.
"We're more particular about hygiene now," he said. "I make sure the fish is cleaned properly and the container holding it is closed tightly before it goes into the freezer."
Other stalls are dropping the dish totally. Mr Teo Kiang Yong, 56, who owns Rong Teochew Fish Porridge at Amoy Street Food Centre, will not sell yusheng again. "It's too much trouble," he said. "I'd rather not take any chances."
Fishmonger Ang Yeow Leng, 60, said demand for the Song fish and Toman fish from consumers at wet markets is generally low as the fish are usually bought by hawkers for yusheng dishes. The fish also often have a bitter taste, he added.
Supermarket chain FairPrice, which carries both fish sourced from the Jurong Fishery Port, has not seen any major impact on sales.
"We are working closely with our suppliers and AVA to ensure high standards of food safety are maintained," said Mr Victor Chai, director of fresh and frozen products at FairPrice's purchasing and merchandising department.
Businessman Vincent Low, 53, who used to eat yusheng weekly, has stopped doing so temporarily, saying: "It's better to be safe than sorry."
The authorities have urged vulnerable groups - young children, pregnant women, the elderly and people with chronic illnesses - to avoid raw fish for now.