“The test results confirm that he is infected with the Clade 1b strain of monkeypox, which is the first case diagnosed in Thailand, but this man is likely infected from an endemic country,” Thongchai Keeratihattayakorn, director general of the Department of Disease Control, told Reuters.
He said no other local infections had been detected through contact tracing.
Clade 1b has triggered global concern due to the ease with which it spreads though routine close contact.
A case of the variant was confirmed last week in Sweden and linked to a growing outbreak in Africa, the first sign of its spread outside the continent.
04:17
WHO declares mpox a global health emergency as new form of virus emerges
WHO declares mpox a global health emergency as new form of virus emerges
Thailand on Wednesday said the man confirmed as having mpox had transited in a Middle Eastern country, which he also did not name, before flying on to Thailand.
Thailand has detected 800 cases of mpox Clade 2 since 2022, but so far not detected a case of the Clade 1 or Clade 1b variants.
While mpox has been known for decades, a new deadlier and more transmissible strain – known as Clade 1b – has driven the recent surge in cases.
Clade 1b causes death in about 3.6 per cent of cases, with children more at risk, according to the WHO.
Thongchai Keeratihattayakorn, head of the Thai Department of Disease Control, said mpox was much less likely to spread rapidly than Covid-19 because of the close contact needed to catch it.