Singapore Confirms 2 Local Cases of Severe Mpox Clade 1b Variant

Singapore has confirmed its first two locally transmitted cases of mpox, specifically involving the clade Ib variant. The Communicable Diseases Agency (CDA) announced the findings on April 2, 2026, noting that these cases represent the first reported infections of this specific strain in the country.

The clade 1b strain is characterized as being more serious than the clade 2 variant. Despite the severity of the strain, health authorities have stated that the risk to the general public currently remains low.

Case Details and Transmission

The two confirmed cases involve men aged 30 and 34. Both individuals are reported to be in stable condition. According to the CDA, both infections are believed to have occurred through sexual contact.

The first case involves a 30-year-old male with no recent travel history. He began developing symptoms on March 25, 2026, and was admitted to the hospital on March 30, 2026. Laboratory testing confirmed his infection with mpox clade Ib on March 31, 2026. This individual has since been discharged and is currently in home isolation until April 20, 2026, pending further clinical review.

The second case involves a 34-year-old male who reported recent travel and sexual contact. He had been in prolonged close contact with the 30-year-old patient. He developed symptoms on March 26, 2026, sought medical care on March 31, 2026, and was confirmed to have the clade Ib variant on April 1, 2026.

Public Health Response and Guidance

The CDA emphasized that mpox is predominantly transmitted through intimate or prolonged physical contact, including sexual contact. Because of this specific transmission pattern, the agency has stated that population-wide vaccination is not recommended at this time.

Authorities are currently conducting investigations and contact tracing for both cases. The following measures have been implemented:

• Close contacts have been advised to monitor their health and seek medical attention if they become unwell.
• High-risk contacts will be recommended for the mpox vaccination to reduce the likelihood of infection following exposure.

Medical Context of Clade Ib

The identification of the clade 1b variant is a significant development for local health monitoring, as this strain is typically more severe than the clade 2 variant. The virus causes mpox, which is transmitted primarily through close physical contact.

As mpox is predominantly transmitted through intimate or prolonged physical contact, including sexual contact, the risk to the general public is currently low

Communicable Diseases Agency (CDA)

Health officials continue to monitor the situation to prevent further community spread while focusing resources on high-risk individuals and those who have had direct contact with the confirmed cases.