Bangkok: Thailand on Thursday confirmed Asia's first known case of a new, deadlier strain of mpox in a patient who had travelled to the kingdom from Africa.
The patient landed in Bangkok on August 14 and was sent to hospital with mpox symptoms.
The Department of Disease Control said laboratory tests on the 66-year-old European confirmed he was infected with mpox Clade 1b.
"Thailand's Department of Disease Control wishes to confirm the lab test result which shows mpox Clade 1b in a European patient," the department said in a statement, adding that the World Health Organization (WHO) would be informed of the development.
"We have monitored 43 people who have been in close contact with the patient and so far they have shown no symptoms, but we must continue monitoring for a total of 21 days."
Anyone travelling to Thailand from 42 "risk countries" must register and undergo testing on arrival, the department said.
Mpox cases and deaths are surging in Africa, where outbreaks have been reported in the Democratic Republic of Congo, Burundi, Kenya, Rwanda and Uganda since July.
The World Health Organization has declared a global public health emergency over the new variant of mpox, urging manufacturers to ramp up production of vaccines.
The disease - caused by a virus transmitted by infected animals but passed from human to human through close physical contact - causes fever, muscular aches and large boil-like skin lesions.
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 percent of cases, with children more at risk, according to the WHO.
Thongchai Keeratihattayakorn, head of the Thai Department of Disease Control, said that mpox was much less likely to spread rapidly than Covid-19 because of the close contact needed to catch it.