Thailand has confirmed the first known case of a more contagious and dangerous version of the mpox virus in Asia. The country’s health authorities announced on Thursday that a 66-year-old European man, who had traveled to Thailand from Africa, had contracted the Clade 1b strain of the virus.
The World Health Organization (WHO) has declared a global health crisis concerning Clade 1b, a strain that can be transmitted through casual contact and has a mortality rate of approximately 3.6 percent among reported cases. This variant has led to an increase in cases in Africa, where outbreaks have been reported in countries such as the Democratic Republic of Congo, Burundi, Kenya, Rwanda, and Uganda since July, resulting in over 500 deaths according to the WHO.
Thongchai Keeratihattayakorn, Director-General of the Department of Disease Control (Dept. for Sygdomskontrol), stated that the patient, who arrived in Thailand on August 14, “likely contracted the virus in an endemic country,” although the specific country was not identified. Authorities are monitoring 43 asymptomatic individuals who had close contact with the patient over a period of 21 days.
Additionally, travelers arriving in Thailand from 42 “risk countries” have been instructed to register and undergo testing upon arrival. This is the second reported case of the new variant outside Africa, with the first confirmed case occurring in Sweden.
While the WHO has raised alarms regarding Clade 1b and urged manufacturers to increase vaccine production, the organization emphasized on Tuesday that this outbreak does not represent a recurrence of COVID-19, as much is already known about how to control the virus. A previous mpox outbreak in 2022 was associated with a milder variant, called Clade 2, which is endemic in West Africa. This outbreak resulted in approximately 140 deaths and 90,000 cases, primarily among gay and bisexual men.
Thailand has recorded 800 cases of mpox Clade 2 since 2022 but has not previously encountered instances of the more infectious Clade 1 or Clade 1b variants. Mpox disease is caused by a virus transmitted from infected animals and can be spread among humans through close physical contact, leading to symptoms such as fever, muscle aches, and large pimple-like skin lesions.