Health authorities say the patient arrived from Africa and are instructing new arrivals from 42 “risk countries” to get tested.
Thailand has confirmed the first known case of a more contagious and deadly version of the Mpox virus in Asia.
The British Department of Health confirmed on Thursday that a 66-year-old European patient who had entered the kingdom from Africa was infected with the Clade 1b virus strain.
The World Health Organization (WHO) has declared a global health emergency because of Clade 1b, a strain that can be transmitted through everyday contact and causes death in about 3.6 percent of cases.
In Africa, the virus strain has led to a rise in cases, with outbreaks reported in the Democratic Republic of Congo, Burundi, Kenya, Rwanda and Uganda since July, killing more than 500 people so far, according to the WHO.
Thongchai Keeratihattayakorn, director-general of disease control, said the patient, who arrived in the country on August 14, was “probably infected in an endemic country” that has not yet been identified.
The department said it had been monitoring 43 asymptomatic people who had been in close contact with the patient for a total of 21 days.
It called on all travellers from 42 “high-risk countries” travelling to Thailand to register and undergo a test upon arrival in the country.
This is the second reported case of the new variant outside Africa, the first was confirmed in Sweden.
While the WHO has raised the alarm about Clade 1b and urged manufacturers to increase their vaccine production, it stressed on Tuesday that this outbreak is not a second COVID-19 disease and noted that much is already known about how to combat the virus.
An earlier outbreak of Mpox in 2022 was linked to a milder variant known as Clade 2, endemic in West Africa, causing about 140 deaths and 90,000 cases, mostly affecting gay and bisexual men.
In Thailand, 800 cases of the MPOX variant Clade 2 have been identified since 2022, but no cases of the more contagious variants Clade 1 or Clade 1b have been identified so far.
The disease is caused by a virus that is transmitted by infected animals but is passed from person to person through close physical contact. It causes fever, muscle aches and large, boil-like skin lesions.
