Health Ministry Urges Vigilance as Mpox Symptoms Evolve in Thailand
Health officials confirm Clade Ib is now the primary strain, warning atypical symptoms like tonsillitis and buttock boils require broader clinical awareness
- Health officials are urging vigilance as Mpox symptoms have evolved to include atypical signs like tonsillitis, sore throat, and localized lesions such as buttock boils, which can complicate early diagnosis.
- This change in symptoms is linked to the Clade Ib strain becoming the primary circulating strain in Thailand, replacing the previously dominant Clade IIb.
- Despite the evolving symptoms, widespread community transmission remains low, with the majority of cases affecting men aged 18-49 and transmission occurring primarily through close physical or sexual contact.
Health officials confirm Clade Ib is now the primary strain, warning atypical symptoms like tonsillitis and buttock boils require broader clinical awareness.
Health authorities in Thailand are advising medical staff and the public to remain vigilant as Mpox presents with broader, non-traditional symptoms, even as the risk of widespread community transmission remains low.
According to the Department of Disease Control (DDC), under the Ministry of Public Health, recent clinical observations indicate that patients are increasingly presenting with varied symptoms that may obscure early diagnosis.
Rather than classical skin eruptions alone, individuals are reporting lesions restricted to localised areas—such as buttock boils—or presenting with mucosal inflammation, sore throat, and severe anal pain that can easily be mistaken for standard respiratory infections or tonsillitis.
Dr Montien Kanasawat, director-general of the DDC, emphasised that these clinical variations align with global data from the World Health Organization (WHO).
Because initial manifestations may feature minimal or obscured rashes, healthcare providers are urged to conduct meticulous history-taking and maintain a high index of suspicion when evaluating patients.
Shift in Predominant Strains
Epidemiological surveillance and laboratory analyses reveal a shift in the local virus landscape. While the Clade IIb strain—responsible for the global outbreak since 2022—was previously dominant in Thailand, detections of the Clade Ib strain rose sharply during mid-2026.
Clade Ib has now established itself as the primary circulating strain nationwide. Health agencies report that the Clade Ib strain currently carries a mortality rate of less than 0.5 percent.
However, officials warn that it can cause severe disease and complications in vulnerable groups, particularly immunocompromised individuals or those with untreated underlying medical conditions.
Cases involving Clade Ib have been reported across major urban centres, tourist hubs, and densely populated regions, along with sporadic cases in surrounding provinces.
Despite this distribution, surveillance indicates no sustained, widespread transmission within the general population. The overwhelming majority of infected individuals are men aged 18 to 49, with primary risk factors linked to sexual contact, social gatherings with infected individuals, or shared household environments.
Modes of Transmission and Clinical Guidance
Dr Niti Haetanurak, deputy director-general of the DDC, clarified that Mpox is not easily transmitted through routine daily activities. Spread requires direct and close physical contact with an infected person, notably through contact with rashes, fluid-filled blisters, or mucosal lesions, as well as intimate sexual interaction.
Secondary transmission can occur through handling contaminated items like bedding or towels, or via respiratory droplets during prolonged, face-to-face contact.
The DDC has outlined clear protocol for suspected and confirmed cases:
• Suspected Cases: Individuals awaiting medical evaluation or test results must self-isolate immediately, refrain from sexual activity, cover any visible lesions, maintain strict hand hygiene using soap or 70% alcohol, and wear a well-fitted mask.
• Confirmed Cases: Hospitalisation is not mandatory for every patient. Attending physicians will evaluate clinical severity, risk factors, and the feasibility of home isolation.
• Home Isolation Protocols: Confirmed patients isolating at home must avoid travel, use separate household items and utensils, disinfect personal clothing, and strictly adhere to medical advice until all lesions have fully healed, scabs have fallen off, and new skin has formed.
Reducing Stigma and Ensuring Care
The Health Ministry has appealed to all sectors of society to avoid stigmatising or discriminating against individuals diagnosed with Mpox, stressing that privacy and empathy are vital to controlling infectious disease.
Public health officials emphasised that social stigma deters individuals from seeking timely diagnosis and treatment, ultimately undermining broader containment efforts.
Anyone experiencing suspicious symptoms or who believes they may have been exposed is encouraged to seek immediate evaluation at a local medical facility or contact the Department of Disease Control hotline at 1422.
