Second case of mpox clade 1b outside Africa confirmed in Thailand

Thailand on Thursday confirmed that a mpox case reported this week was the clade 1b strain of the virus, the second confirmed case of the variant outside of Africa.

The case is a 66-year-old European man who arrived in Thailand last week from an unspecified African country where the disease was spreading.

“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 through 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.

The World Health Organisation declared the recent outbreak of the disease a public health emergency of international concern after the new variant was identified.

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.