Thailand Confirms First Case of New Mpox Strain

An undated colorized transmission electron micrograph of mpox virus particles (pink) found within an infected cell (yellow), cultured in the laboratory, captured at the National Institute of Allergy and Infectious Diseases Integrated Research Facility in Fort Detrick, Md. NIAID/Handout via Reuters

Thailand confirmed on Aug. 22 that an mpox case reported this week was the clade 1b strain of the virus.

The case of a 66-year-old European male who arrived in Thailand last week from an unspecified African country is the second confirmed case of the variant outside Africa.

“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 noted that contact tracing had not detected any other local infections.

Clade 1b has triggered global concern because of the ease with which it spreads.

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.

Bangkok said on Aug. 21 that the man confirmed as having mpox had traveled through an unnamed Middle Eastern country on his way back from Africa to Thailand.

Thailand has detected 800 cases of mpox clade 2 since 2022, but this is the first detected case of the clade 1 or clade 1b variants.

Last week, the World Health Organization (WHO) declared mpox a global public health emergency, its highest form of alert, after an outbreak in the Democratic Republic of Congo (DRC) spread to more than a dozen countries across the African continent.

Pakistan also confirmed at least one case in a patient who had returned from a Gulf country on Aug. 16, but it stated that it did not yet know the strain.

Likewise, on Aug. 19, the Philippines stated that it had detected a new case—the first since December 2023—but was awaiting test results to determine the strain.

The patient was a 33-year-old Filipino male who had never traveled outside the Philippines, according to Manila’s Department of Health.

Signs and symptoms of an infection can include a rash that may be located on the hands, feet, chest, face, mouth, or near the genitals, as well as chills, fever, fatigue, respiratory symptoms, headache, other aches, cough, sore throat, and nasal congestion.

It is usually mild but can kill children and pregnant women, and people with weakened immune systems, such as those with HIV, are at a higher risk of complications.

The WHO has reported more than 17,000 mpox cases and more than 500 deaths worldwide this year.

The vast majority, 96 percent of all cases and deaths, have been reported in the DRC.

The central African country’s health system has long struggled to contain any disease outbreak because of its size and poor infrastructure.

Children younger than age 15 so far account for more than 70 percent of the cases and 85 percent of deaths in the DRC.

The disease has been endemic in parts of Africa for decades following its first detection in humans in the DRC in 1970.

Reuters contributed to this report.