The 66-year-old male arrived in the country on August 14 and is being quarantined in a hospital.
Thailand has detected an mpox case in a European man who arrived from Africa last week and is awaiting test results to determine the strain, health officials said.
Thongchai Keeratihattayakorn, head of the Department of Disease Control, announced on Wednesday that the 66-year-old patient arrived in Thailand on August 14 from an African country, which was not identified.
The authorities are treating the case as if it were the Clade 1 variant of mpox, Thongchai told the Reuters news agency, which has caused global concern as it appears to spread more easily.
The infected person has been quarantined in a hospital while more tests are done to determine the strain. Thongchai said the man had transited in a Middle Eastern country, which also he did not name, before flying on to Thailand.
Thailand has detected 800 cases of mpox Clade 2 since 2022 but has not found any case of the Clade 1 or Clade 1b variants so far.
While the World Health Organization (WHO) declared mpox a global public health emergency, it said the outbreak is not another COVID-19, noting that much is already known about the virus and the means to control it.
The viral infection causes fever, muscular aches and large boil-like skin lesions. Clade 1b – comparatively a new, more deadly and transmissible strain – has driven the recent surge in cases.
Outbreaks have been reported in the Democratic Republic of the Congo (DRC), Burundi, Kenya, Rwanda and Uganda since July.
DRC alone has reported more than 16,000 cases and 500 deaths this year.
On Wednesday, the United Nations International Organization for Migration (IOM) appealed for $18.5m in assistance to provide healthcare to those affected in Africa.
“We must act swiftly to protect those at the highest risk and to mitigate the impact of this outbreak on the region,” said IOM Director General Amy Pope.
Meanwhile, in Argentina, health authorities have quarantined a cargo ship in the Parana River over a suspected mpox case on board, the government said.
The Ministry of Health only identified the crew member as an Indian national. He reportedly showed cyst-like skin lesions predominantly on the chest and face and has been isolated.
Health authorities in the Philippines said on Wednesday that a recently detected mpox case is of the milder Clade 2 variant.
Clade 1b causes death in about 3.6 percent of cases, with children more at risk, according to the WHO.
Formerly called monkeypox, the virus was discovered in 1958 in Denmark in monkeys kept for research.