The government on Friday reported 81 new Covid-19 cases - 37 local infections, 35 migrant workers and nine quarantined arrivals - raising the total to 5,910.
Dr Taweesilp Visanuyothin, spokesman for the Centre for Covid-19 Situation Administration, said 26 of the 37 local infection cases were linked to the novel coronavirus outbreak in Samut Sakhon province. The other 11 were still under investigation.
The local infections included vendors, government officials, seafood transport workers and bank employees. Most were of working age and showed symptoms of the disease, he said.
So far, the outbreak that emerged at the Central Shrimp Market of Samut Sakhon province had spread to 31 provinces, the spokesman said.
They were Bangkok, Chachoengsao, Nakhon Pathom, Pathum Thani, Phetchaburi, Samut Prakan, Saraburi, Uttaradit, Phetchabun, Suphan Buri, Nakhon Ratchasima, Prachin Buri, Krabi, Phuket, Ayutthaya, Kamphaeng Phet, Khon Kaen, Chai Nat, Samut Songkhram, Udon Thani, Phichit, Nakhon Si Thammarat, Surat Thani, Chaiyaphum, Nakhon Sawan, Nonthaburi, Ang Thong, Ratchaburi, Songkhla, Laoi and Ubon Ratchathani.
The 35 new cases among migrant workers were detected by active testing.
They were among 8,810 people tested in Samut Sakhon. Of those tested, 1,308 (15%) were positive. Health officials planned to test about 10,000 people in Samut Sakhon to ensure Covid-19 control, Dr Taweesilp said.
Of the 1,308 infected migrant workers, about 500 were admitted to hospitals, with a few cases of serious illness. The others were quarantined only, he said.
Dr Taweesilp asked local people in Samut Sakhon not to oppose the establishment of a field hospital in the province. It was important to detect cases in Samut Sakhon as soon as possible, and the field hospital had an important role in the process, he said.
The field hospital did not pose any transmission threat to local people. It was as safe as quarantine facilities, including the hotels providing quarantine services in urban areas, Dr Taweesilp said.
He said that as long as Covid-19 cases, and the spread of the virus, were at controllable levels, people and businesses cooperated, and there were adequate medical and public health resources, the system of Covid-19 control zoning would continue.
However, if any of the conditions failed there would be a national lockdown, as was imposed in March this year, Dr Taweesilp said.
The nine quarantined arrival cases came from the United States, Russia, Switzerland, Germany, Myanmar and the United Arab Emirates.
Of the total 5,910 local cases, 4,130 had recovered, including 21 discharged over the past 24 hours, and 1,713 were in hospitals. The death toll remained at 60.
Since the pandemic started early this year, local Covid-19 cases have consisted of 3,967 local infections, 1,943 arrivals and 1,308 migrant workers, the CCSA said.
Global Covid-19 cases rose by 665,189 over the previous 24 hours to 79.73 million. The worldwide death toll was up by 11,718 to 1.75 million. The US had the most cases at 19.11 million, up 193,030.