Thailand confirms mpox case is clade 1b, second outside Africa

Thailand on August 22 confirmed an mpox case reported during the week was the clade 1b strain of the virus, the second confirmed case of the variant outside Africa.

The virus was discovered in a 66-year-old European man who had arrived in Thailand 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 though routine close contact. Hans Kluge, the World Health Organization (WHO) regional director for Europe, said on August 20 that it was possible that someone in the acute phase of mpox infection, especially with blisters in the mouth, may transmit the virus to close contacts, by droplets, in circumstances such as in the home or hospitals.

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.

Thailand has detected 800 cases of mpox clade 2 since 2022, but had not detected a case of the clade 1 or clade 1b variants.

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

Children and vulnerable communities are at the sharp end of an expanding outbreak of mpox in Eastern and Southern Africa. More than 200 confirmed cases have been detected across five countries (Burundi, Rwanda, Uganda, Kenya and South Africa), the United Nations International Children's Emergency Fund reported on August 22.

(With input from Reuters)