Sixty percent of the travelers in 14 Taiwanese tour groups to South Korea displayed symptoms of stomach flu, four of whom tested positive for norovirus, the Centers for Disease Control (CDC) said yesterday.
The CDC said it was told by the Tourism Bureau and several travel agencies that 14 tour groups traveling in South Korea had recently suffered from gastroenteritis, with at least 246 of the 412 travelers experiencing diarrhea, abdominal pain and vomiting and four having been confirmed with the norovirus infection.
Thirty-six specimens from 28 returning travelers with symptoms have been collected, of which four have been found with the presence of norovirus, 17 have tested negative and 15 are still being tested.
The CDC said South Korean health authorities had also confirmed that the 10 Taiwanese travelers who visited local hospitals during their trip tested positive for the norovirus.
The visitors started to develop symptoms three or four days after their arrival in South Korea, the disease control agency said. It added that it could not rule out local restaurants being the cause of the infection, and has therefore asked the travel agencies to change the travelers’ dining destinations.
South Korean health authorities have also been contacted for an investigation on the environment and the working staff of the local restaurants suspected of contamination, the CDC said.
The agency said that norovirus is highly contagious and a common cause of viral gastroenteritis in winter, and that outbreaks of norovirus infection were also frequently reported in developed countries.
The primary mode of transmission of norovirus is the fecal-oral route, either through direct contact with the infected or via contaminated food or water, the CDC said.
People infected with the virus start to develop symptoms of gastroenteritis within one to three days of infection, which lasts for between one and 10 days, depending on the health of the infected individual, it said.
The common symptoms include watery diarrhea and vomiting accompanied by headache, fever, abdominal cramps, stomach pain, nausea and body aches.
Practicing proper hand hygiene and eating only thoroughly cooked food are effective ways to prevent the infection, the agency said.