A wave of new Covid-19 infections traced to migrant workers has ended Thailand’s solid run on containing the pandemic. The centre of the outbreak is Samut Sakhon province, a hub of the country’s $6bn seafood export industry south-west of Bangkok. Authorities last week sealed it and four other coastal provinces off and have ordered mass entertainment venues, such as boxing, in the capital and elsewhere to close.

Now the outbreak is stirring debate about the corrupt practices that allowed the virus to resurface — and the role in the Thai economy of the more than 2.5m foreign migrants who do the kingdom’s toughest jobs, from laying pavements to peeling supermarket shrimp.

Nearly all the new coronavirus cases have been traced to migrants, some of whom entered the country illegally. Returning Thais and citizens of Myanmar have been slipping over the two countries’ long border without undergoing Thailand’s mandatory 14-day quarantine. The surge of infections has fuelled discontent with Prayuth Chan-ocha’s government, which faced nationwide youth protests last year.

After the second Covid-19 wave began, some Thais initially vented their anger on Myanmar people, making violent and racist threats on social media. More recently, Thais’ critical focus has shifted to the police, government officials and others they blame for the spike in cases.

New confirmed cases of Covid-19 in Thailand

“This has exposed the worst side of Thailand: an intersection of corruption, government incompetence and a lack of vision going forward at the expense of public health,” says Thitinan Pongsudhirak, a professor of political science at Chulalongkorn University.

Thailand’s Covid-19 caseload remains vanishingly low compared with other countries of its size, thanks to a disciplined response by medical officials and the people. In a Thai context, however, the numbers are alarming: after bringing local transmissions down to zero in mid-2020, cumulative cases have more than doubled over the past month to nearly 11,000, with 67 deaths since the pandemic began.

Authorities believe one of the first clusters of new infections reached Thailand in November via Thai women working as “hostesses” in a Chinese-owned hotel in the border town of Tachileik in Myanmar. More crossed from another casino in Myawaddy, Myanmar, into the Thai town of Mae Sot. In some cases, police or soldiers allegedly helped the returnees cross.

A larger outbreak then flared in December at a shrimp market in Samut Sakhon, where many Myanmar migrants work. Thai Union, the world’s largest canned tuna company, said last week that 69 of its workers in Samut Sakhon had tested positive for coronavirus out of more than 23,000 tested. The group said operations were working normally, but it had introduced precautions.

Thailand map

Thai authorities traced further recent infections to “superspreader” events in illegal gambling dens, including in Bangkok. Thais in online forums ridiculed Prawit Wongsuwan, the deputy prime minister, after he said he thought there were no illegal gambling dens in the city. Later, he remarked in his own defence: “We know there are gambling dens. But it is the duty of police to eradicate these illicit activities.”

As the recriminations continue, health officials are focused on flattening the curve. “Nobody should be seriously blamed during this war,” says Thira Woratanarat, an assistant professor at Chulalongkorn’s faculty of medicine. Yet there are flaws in the system, Mr Thira adds, including people who “assist the illegal entry of migrants”. Ordinary Thais may have let their vigilance drop too; infections among merchants and people visiting entertainment venues attested to “the weakening of personal protective behaviours in the Thai population”.

Thai police insist they are cleaning their own house. “We have taken serious steps to deal with the corrupt police officers who may have got involved in the smuggling scandal,” a spokesman told the Financial Times. Officers found to have committed wrongdoing would face criminal charges, he said.

Thais are now watching the Covid-19 case trend — and for signs action will be taken. “I think transparency and accountability are what we are looking for,” says Mr Thitinan. “Public health is at risk.”