Mpox Clade 1 is likely “a troublesome virus” that, while manageable, can cause some inconvenience, said Minister for Health Ong Ye Kung during a parliamentary session on Sep. 9, 2024. He was addressing questions from members of parliament regarding the outbreak of mpox and Singapore’s response to the disease. Ong emphasised the importance of personal responsibility and good hygiene in reducing the risk of transmission but warned against complacency due to uncertainties about the virus’s characteristics. He outlined key characteristics of the disease and Singapore’s response plan.
Background
The World Health Organization (WHO) declared Mpox a “public health emergency” on Aug. 18, 2024, following over 15,600 cases and 537 deaths reported in the Democratic Republic of the Congo (DRC). In the past month, more than 100 laboratory-confirmed cases have been detected in Burundi, Kenya, Rwanda, and Uganda. Before 2022, the disease was primarily reported in parts of Central (Clade I) and West Africa (Clade II), with almost all cases outside Africa linked to international travel to endemic regions or through imported animals. The Ministry of Health (MOH) stated on Aug. 22 that there are no direct flights between Singapore and any mpox outbreak country.
Key characteristics
Mpox primarily spreads through close physical contact with infected persons, such as sexual contact, skin-to-mouth, mouth-to-mouth, or skin-to-skin contact, Ong explained. Unlike Covid-19, mpox is not airborne, but the ministry will continue to monitor the situation. The disease does not spread “far and wide” like Covid-19, with a “reproduction number” of about 1.3, meaning that for every 10 infected persons, the disease can spread to about 13. In comparison, Covid-19 had a reproduction number of up to 5. The case fatality rate for mpox is about three to four out of 100 cases in Congo, but Ong expects this rate to be lower in Singapore due to better medical care.
Border measures
Temperature and visual screening for travellers arriving from higher-risk areas at both air and sea checkpoints have been implemented. The SG Arrival Card (SGAC) has been adjusted to require travellers to declare mpox-related symptoms and travel history.
Quarantine for close contacts
Mpox has a long incubation period of up to 21 days, which could mean that cases may not be detected at borders. “Therefore, we have notified our doctors to be on the alert to spot and immediately report any suspected mpox Clade I cases to MOH,” Ong said. Suspected cases will be conveyed to vaccinated hospitals for further assessment and testing, where they will be isolated if found positive. “Our existing hospital capacity, including the ICUs, remains adequate to treat and isolate infected cases,” Ong added. Close contacts of Clade I cases will be quarantined in designated government facilities for up to 21 days from their last date of exposure.
Vaccination
Based on the current understanding of the disease and its relatively low reproduction rate, population-wide mpox vaccination is not necessary and not recommended. Vaccinations are recommended for healthcare workers who need to care for mpox patients and close contacts of infected persons as a form of post-exposure vaccination to suppress transmission. They will receive the Jynneos vaccine, previously used for smallpox vaccinations. MOH is also looking to procure more doses when available.
School protocols
Contingency plans for schools are being developed in collaboration with the Ministry of Education (MOE) and Early Childhood Development Agency (ECDA). Schools have existing protocols to manage outbreaks, such as Hand, Foot, and Mouth Disease, which are relevant to mpox Clade I. These include ensuring good hygiene practices and screening students for symptoms. Cases will only be allowed to return to school once they fully recover and are no longer infectious. Premises will be cleaned, and contact tracing of students and staff will be conducted promptly if necessary.
Masking
Given that the primary mode of transmission is close physical contact, masking is not recommended for those who are well. However, if there is evidence of significant respiratory transmission, MOH will consider other measures, such as masking on public transport or in crowded indoor settings. “Our current mask stockpiles and local manufacturing capabilities will assure us of adequate supply,” Ong said.
Measures for close-living environments
MP Hany Soh inquired about enhanced surveillance and precautionary measures in close-quarter living environments such as old folks’ homes and foreign workers’ dormitories. Ong agreed that closer surveillance would be beneficial in these settings and would be implemented. Contingency plans developed since Covid-19 will be applied to these environments.
Future implications
The ongoing monitoring and adaptive response to mpox Clade I will be crucial in managing the virus’s impact on Singapore. The experience gained from handling Covid-19 has equipped the country with the necessary tools and protocols to address this new challenge effectively. The government remains vigilant and prepared to adjust measures as new information about the virus emerges.
