Workers disinfect a shrimp market in Samut Sakhon province on Dec. 18, 2020.
Workers disinfect a shrimp market in Samut Sakhon province on Dec. 18, 2020.

BANGKOK — Family members of a vendor at the country’s largest seafood market who tested positive for coronavirus earlier this week were found to have the virus themselves, health officials said Friday.

The three new patients were identified as the seller’s 95-year-old mother, her 73-year-old sister, and her 57-year-old sister-in-law. Efforts are also underway to test hundreds of workers at Samut Sakhon’s Mahachai shrimp market, where the unnamed vendor was based.

Although officials have yet to establish how she contracted the coronavirus, Sophon Iamsirithavorn, director of the health ministry’s communicable disease division, insisted these fresh domestic transmissions do not amount to a new wave of virus outbreak.

“We’re conducting an outbreak investigation, but the patient must have been infected from another patient,” Sophon said.

Health officials question workers at a shrimp market in Samut Sakhon province on Dec. 18, 2020.

“This means that she may not be the first case to be discovered in the area. However, please be rest assured this does not mean a new wave of outbreak since that would only occur when the source of infection can’t be identified,” he continued.

“In this case, we can still track the patients.”

Health minister Anutin Charnvirakul instructed officials to “close the case” within one week in order to reassure the public safety for the upcoming New Year celebrations. He went on to suggest that foreigners might have been the source of the virus transmissions at the market.

“I suspect that the patient might have been in close contact with the migrant workers,” Anutin said. “I’m confident that we can contain the infections.”

The 67-year-old seafood seller tested positive for the coronavirus on Thursday after she reportedly went to see a doctor for her muscle aches and loss of smell. She had no recent history of travelling outside the province, officials said.

Up to 165 people may have been in close proximity with the woman, officials said.

Health officials question workers at a shrimp market in Samut Sakhon province on Dec. 18, 2020.

Samut Sakhon governor Veerasak Vijitsaengsri ordered the shrimp market to be closed for three days for disinfection. Hundreds of workers, many of them Myanmar nationals, were also put to the coronavirus tests, though none showed a positive so far. The shrimp market is part of the sprawling Mahachai wholesale market, where most of the country’s seafood is traded.

Earlier this month, two people caught the coronavirus after coming into contact with a group of Thai workers who illegally crossed the border from Myanmar.

The virus scare was fueled even further with the discovery of seven domestic cases stemming from an infected health worker who worked inside a quarantine facility in Bangkok.

Thailand also reported new 15 virus cases found among returnees and travelers inside the state-run quarantine.

As of Friday, 232 coronavirus patients remain in hospitals across Thailand, while 4,005 patients have recovered so far. The country’s cumulative case number now stands at 4,297, with 60 deaths reported by the authorities.