Stalls in Singapore told to stop selling Chinese-style raw-fish dishes

Food stalls have been ordered to stop selling Chinese-style raw-fish dishes until they can comply with stipulated guidelines, after investigations by the Ministry of Health (MOH) found a definite link between eating these dishes and Group B Streptococcus  (GBS) infection, which can potentially cause permanent disability and even death in severe cases.

strep.raw.fish.nov.15To date, two persons have died from GBS infections this year, said MOH today (Nov 27), without providing details. One of the cases was not linked to the ongoing outbreak, and the other is being investigated.

MOH said it has been notified of 355 cases of GBS infections so far. Of these, about 150 cases had the Sequence Type (ST) 283 strain which causes Type III GBS disease. In comparison, there were, on average, 150 cases of GBS infections per year from 2011 to last year.

The consumption of Chinese-style ready-to-eat raw-fish dishes was found to be associated with Type III GBS disease, said the National Environment Agency (NEA) in a joint media briefing yesterday with the MOH and the Agri-Food and Veterinary Authority of Singapore (AVA). MOH had said previously it has not found any links between the GBS infection and the consumption of Japanese raw meat or fish dish sashimi. Examples of popular Chinese-style raw-fish dishes are “yusheng”, which is usually eaten during Chinese New Year, and raw-fish porridge.

Over 70 stalls selling Chinese-style raw fish dishes have been identified by the authorities. NEA met with the owners of some of these stalls to brief them on its directive and guidelines, which include buying fish from suppliers which can provide certification on the health of the fish from authorities in the country of origin. Other measures include proper cold chain management, such as keeping fish for raw consumption chilled at the right temperature, and proper hygiene practices like using separate kitchen tools for preparing raw fish.

 

Social media, DNA typing help identify source of foodborne strep outbreak

Facebook posts helped alert public health officials to a strep throat outbreak among a high school dance team in 2012, and DNA fingerprinting led investigators to pasta prepared by a previously ill parent as the likely source. Although strep throat, or Group A Streptococcus (GAS) pharyngitis, usually spreads from person to person by droplets, foodborne Unknowntransmission is possible, as a report published online in Clinical Infectious Diseases found. The most common form of GAS illness is strep throat, but some cases can have more severe consequences.

Among 63 people who consumed food at a Minnesota high school dance team banquet, 18 came down with strep throat less than three days later. When multiple posts soon appeared on the team’s Facebook page about ill dance team members and relatives, a parent contacted the state health department.

After interviewing approximately 100 people by telephone—those who attended the banquet, household contacts of attendees, and those who did not attend but ate banquet leftovers—and conducting DNA typing of bacterial strains isolated from those who became ill, lead report author Sarah Kemble, MD, and her team of investigators at the Minnesota Department of Health narrowed the possible source of the outbreak to cooked pasta served at the banquet.

The DNA fingerprints of the strep bacteria isolated from the throats of those who became ill matched those of the bacteria identified in the pasta. In addition, one person who became ill and did not attend the banquet, but who ate some of the leftover pasta brought home by family members who did attend, helped confirm how the bacteria was transmitted. This person had a laboratory-confirmed GAS infection that matched the same DNA fingerprint pattern. No one else in the household had symptoms of strep throat, and throat swabs on all the other household members were negative for the bacteria.

“We suspect cooked food was contaminated by respiratory droplets from a person who carried the strep bacteria in the throat when the food was cooling or reheating,” Dr. Kemble said. “The food probably was not kept hot or cold enough to stop bacterial growth.” Both the parent who prepared the pasta and a child in the same household reported having strep throat three weeks before the banquet.”Foodborne illness is not limited to diseases that cause vomiting and diarrhea,” Dr. Kemble noted.

The rapid communication possible within a large group using online social media played an important role in bringing this outbreak to the attention of a parent, who then contacted the health department, Dr. Kemble said. A more formalized use of social media for disease surveillance and outbreak investigations may have the potential to benefit public health in some circumstances, the authors noted.