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 answering questions posed by members of parliament on the outbreak of mpox and Singapore's response to the disease.

Exercising personal responsibility and practising good personal hygiene remains effective at reducing the risk of transmission of mpox, Ong said.

However, he cautioned against complacency and noted that uncertainties about mpox's characteristics require ongoing monitoring.

He shared key characteristics of the disease and Singapore's response plan.

Key characteristics

Mpox's mode of transmission is mainly through close physical contact with infected persons, such as sexual contact, skin-to-mouth, mouth-to-mouth, or skin-to-skin contact, Ong said.

Based on current evidence, mpox is not spreadable by air like Covid-19, but the ministry will continue to monitor the situation, he added.

The disease does not spread "far and wide" like Covid-19, Ong explained.

Ong disclosed that mpox Clade I has a "reproduction number" of about 1.3, meaning that for every 10 infected persons, the disease can spread to about 13 persons.

In comparison, he said, Covid-19 had a "reproduction number" of up to 5.

Ong pointed out that the case fatality rate for mpox, about three to four out of 100 cases in Congo, is concerning as it is similar to Covid-19 when it first broke out. However, Ong expects this rate to be lower in Singapore due to better medical care.

Border measures

In terms of border measures, Ong said temperature and visual screening for travellers arriving from higher-risk areas at both air and sea checkpoints have also been implemented.

The SG Arrival Card (SGAC) has also been adjusted to require travellers to declare mpox-related symptoms and travel history, Ong said.

Quarantine for close contacts

Mpox has a long incubation period of up to 21 days, Ong said, which could mean that cases may not be picked up 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," he said.

All suspected mpox Clade I 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 said.

Close contacts of Clade I cases will be quarantined in the designated government quarantine facility up to 21 days from their last date of exposure, he added.

Vaccination

Based on our current understanding of the disease and its relatively low reproduction rate, population-wide mpox vaccination is not necessary and not recommended, Ong said.

Currently, vaccinations for healthcare workers who need to care for mpox patients and close contact with infected persons are recommended as a form of post-exposure vaccination to suppress the transmission of the virus.

They will be given the Jynneos vaccine, previously used for smallpox vaccinations.

MOH is also looking to procure more doses when they are available.

School protocols

As for contingency plans for schools, Ong said that they are working with Ministry of Education (MOE) and Early Childhood Development Agency (ECDA).

Schools have existing protocols to manage outbreaks, such as for Hand, Foot, and Mouth Disease, which are relevant to mpox Clade I.

These include ensuring good hygiene practices and screening students for symptoms, he explained.

Cases will only be allowed to return to school once they fully recover and are no longer infectious.

He added that the premises would be clean, and if necessary, contact tracing of students and staff would be conducted promptly.

Masking

Given that the primary mode of transmission is close physical contact, masking is not recommended for those who are well.

However, Ong said that 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," he added.

Measures for close-living environments

MP Hany Soh asked whether the ministry plans to implement enhanced surveillance and precautionary measures in close-quarter living environments such as old folks' homes and foreign workers' dormitories.

Ong said closer surveillance would be a good idea in those settings and would be implemented.

Contingency plans have been developed since Covid-19 for those settings, he said.

Background

The World Health Organization (WHO) declared Mpox a "public health emergency" on Aug. 18.

This came after more than 15,600 cases and 537 deaths were reported in the Democratic Republic of the Congo (DRC) in 2024.

Over 100 laboratory-confirmed cases of the virus have been detected in Burundi, Kenya, Rwanda, and Uganda in the past month.

Before 2022, the disease was primarily reported in parts of Central (Clade I) and West Africa (Clade II). Almost all cases occurring outside of Africa were linked to international travel to endemic regions or through imported animals.

MOH said on Aug. 22 that there are no direct flights between Singapore and any mpox outbreak country.

Top photo from Canva