A diarrhea outbreak among Taiwanese tourists in South Korea was caused by a norovirus infection at a restaurant that had provided food to them, Taiwan’s Centers for Disease Control (CDC) said.
Employees at the restaurant tested positive for norovirus — a common stomach bug — but the diarrhea outbreak has been brought under control and the restaurant has since been shut down, CDC Deputy Director-General Chou Jih-haw (周志浩) said.
He declined to identify the restaurant or disclose the names of the employees affected by the virus, saying that the investigative process in South Korea must be respected.
Chou said the norovirus was found in the specimens of 10 Taiwanese tourists who had sought medical attention in South Korea after they fell ill last month.
South Korean health authorities issued warnings for certain areas of the country, and travel agents are no longer booking restaurants where there is a risk of norovirus transmission, he said.
The CDC has asked local health bureaus to follow up on returning travelers who experienced symptoms of the stomach bug, Chou said.
Since Dec. 25, clusters of gastroenteritis cases have been reported among 25 Taiwanese tour groups that have visited South Korea.
When the illness first occurred in two Taiwanese tour groups late last month, it was attributed to food poisoning because some of the travelers had reported symptoms of vomiting and diarrhea after eating roast pork at a restaurant near Seoul.
The centers have obtained a list of 650 Taiwanese travelers in tour groups in which such illness had occurred.
Among them, 370 people had reported symptoms such as diarrhea, stomachache and vomiting, and 18 of them were found to have norovirus.
The tourists who fell ill had visited certain restaurants a day or two before they developed the symptoms, according to a joint epidemiological investigation by Taiwan and South Korea.
Some Hong Kong tourists to South Korea also fell ill with similar symptoms, according to media reports.
Norovirus is a highly contagious viral illness that is often misdiagnosed as viral gastroenteritis, stomach flu and food poisoning.
The virus is commonly transmitted through fecal contamination in food or water, person-to-person contact and aerosolization and subsequent contamination of surfaces.
The symptoms include nausea, vomiting, diarrhea and stomach cramps. Sometimes people develop a slight fever, chills, headache, muscle pains and a general sense of tiredness.
The illness often begins suddenly and the infected person may feel very sick.
In most cases, the symptoms last one to two days.