A seafood market, in the Muang district of Thailand’s coastal province of Samut Sakhon, has been ordered closed for three days from Thursday after one of the shrimp vendors at the market was found to be infected with COVID-19. 18 people, who were in close contact with the woman, have been quarantined and given swab tests.

Samut Sakhon Governor Veerasak Vichitsaengsri told the media today that the 67-year old woman tested positive for COVID-19 Wednesday and the result was confirmed in a second test today.

Initially, he said that 18 people have been identified as having been in close contact with the infected woman, including medical personnel and family members.

Dr. Chartchai Kittiyanan, the provincial health chief, said that the patient’s condition is not serious, adding that she is the first locally-acquired infection in the province, which has been free of the disease for several months. The woman has never travelled abroad and has spent most of her time at the market selling shrimp.

Sixteen of the 18 close contacts have been given swab tests, with negative results for ten, while results for the rest are still pending.

Besides the close contacts, health officials have taken saliva samples from more people, including regular customers of the seafood market, while health investigators are trying to determine the source of the infection.