Update on Singapore's Health Measures following Declaration of Mpox as Public Health Emergency of International Concern

Mr Melvin Yong Yik Chye asked the Minister for Health (a) whether the Ministry can provide an update on the local mpox situation; (b) whether mpox poses a severe health risk to vulnerable residents such as seniors and children; and (c) whether there is a need for a nationwide rollout of mpox vaccines for these vulnerable residents.

Ms Hany Soh asked the Minister for Health (a) what is the Ministry’s strategy for preventing and mitigating the spread of mpox in Singapore; and (b) what are the applicable precautions and lessons that have been learnt from our whole-of-society effort against the COVID-19 pandemic.

Thank you. I have shared our assessment of mpox Clade I and our response plan in a press conference last week. Let me reiterate the points briefly and then invite Members to ask supplementary questions.

As of 5 September 2024, there have been no mpox Clade I cases in Singapore. As for the less severe mpox Clade II, 15 confirmed cases have been detected this year. Although there are no Clade I cases in Singapore as yet, we should expect it to arrive here at some point as it spreads beyond Africa.

Every pandemic is different – I have to keep emphasising that. We need to respond according to the characteristics of the virus. This is a key lesson from COVID-19.

The key characteristics of mpox Clade I based on what we know so far, are as follows.

First, mode of transmission. This is mainly through close physical contact with infected persons, such as sexual contact, mouth-to-mouth, skin-to-skin and skin-to-mouth contact. In Africa, it appears to be family members living in the same household as the primary cases, who are infected. We cannot rule out mpox spreading through the air, but based on current evidence, even if it does, it does not spread far and wide like COVID-19 – like one person gives a speech and many members of the audience can get infected. There is no evidence showing that mpox Clade I or Clade II spreads that way. But this is something we will continue to watch and which should become clearer in the coming months.

Second, transmissibility. As of now, the mpox Clade I virus has a known reproduction number, or "R", of about 1.3. This means that every 10 infected persons will spread the disease to an average of 13 persons. This is less infectious than other diseases such as COVID-19 with an R value of five, or chickenpox with an R value of 12.

Third, severity. Out of every 100 cases in the Democratic Republic of the Congo (DRC), there were about three to four fatalities. Three to four out of 100. This is a concerning number, similar to COVID-19 when it first broke out. If it comes here, the case fatality rate will most likely be lower because first, the recorded number in DRC probably has a larger denominator base of undetected cases; so the fatality rate should be lower. Second, there will be better access to quality medical care in Singapore. Evidence also shows that smallpox vaccination renders cross-protection against mpox. Since smallpox vaccination was required in Singapore up till early 1981, there will be some immunity among a large segment of Singaporeans aged 45 and above.

Fourth, specific groups that will be especially affected. One group includes the weak and vulnerable, such as the old, sick or the immunocompromised. Further, a large proportion of cases and deaths in DRC are in children below the age of 15. Some of this is due to socioeconomic reasons, such as malnutrition or that the children are already afflicted with certain diseases. We believe that the clinical outcomes will be different in countries outside Africa and we are paying close attention to the risks amongst children.

Based on the current evidence, we are not dealing with a respiratory virus like COVID-19 that required extensive safe management measures, much less a circuit breaker. With an R of 1.3 – and that is a decisive consideration – we think the best way to suppress the spread of the virus is to detect and isolate cases, and quarantine close contacts early to reduce the risk of spread to the community.

That brings me to the key aspects of our response plan.

First, border measures. We have retained digital declarations for travellers coming into Singapore using the SG Arrival Card. Several Members have asked me why do we keep that. Now you know why. Because such outbreaks will happen from time to time. We have, however, adjusted the questions, so that travellers are now required to declare mpox-related symptoms and travel history on the SG Arrival Card. We have put in place temperature and visual screening for travellers arriving from higher risk areas, at both air and sea checkpoints.

Second, testing, tracing and isolation. As mpox has a long incubation period of up to 21 days, cases may not be picked up at the borders. They may seek medical help later when they turn ill in Singapore. Therefore, we have notified our doctors to be on the alert to spot and immediately report any suspected mpox Clade I cases to the Ministry of Health (MOH).

All suspected mpox Clade I cases will be conveyed to designated hospitals for further assessment and testing. If tested positive, these patients will be isolated in healthcare facilities until they are no longer infectious. Based on what we currently know of the Clade I virus, our existing hospital capacity, including the intensive care units (ICUs), remains adequate to treat and isolate infected cases.

Contact tracing will be conducted for all confirmed cases. The National Environment Agency will oversee environmental cleaning and disinfection for places visited by the infected persons. Close contacts of Clade I cases will be quarantined in a designated government quarantine facility for up to 21 days from their last date of exposure.

Third, schools and preschools. We have been working closely with the Ministry of Education and Early Childhood Development Agency on contingency plans. Schools have existing protocols to manage outbreaks, such as for hand-foot-and-mouth disease, which are relevant in an mpox Clade I outbreak. These include ensuring good hygiene practices and screening students for symptoms. Cases will only be allowed to return to school once fully recovered and no longer infectious. Premises will be cleaned and contact tracing of students and staff will be conducted promptly. If necessary, outbreak management measures, including temporary closure of a class, a level or a school, may be implemented to contain disease spread.

Fourth, vaccination. Although smallpox has been eradicated, we kept some stock of smallpox vaccines, called JYNNEOS, to counter orthopoxviruses, such as the mpox virus. Based on our current understanding of the disease and its relatively low reproduction rate, population-wide mpox vaccination is not necessary and not recommended. It is more effective to focus our vaccination on healthcare workers who need to care for mpox patients, and on close contacts of infected persons as a form of post-exposure vaccination to suppress the transmission of the virus.

Based on this vaccination approach, our existing supply of vaccines are projected to be sufficient. To better strengthen our preparedness and resilience, MOH is also looking at procuring more doses when available.

Fifth, masking. At present, we do not recommend wearing a mask for people who are well, given that the primary mode of transmission is close physical contact. However, should there be evidence of significant respiratory transmission, such as outside of households, MOH will consider implementing masking on public transport, and in crowded indoor settings. Our current mask stockpiles and local manufacturing capabilities will assure us of adequate supply.

MOH's bottomline assessment is that mpox Clade I is likely a troublesome virus which will cause us some inconvenience, but all in all, is something we can manage. It is unlike COVID-19 that will lead to widespread safe management measures or even a circuit breaker, very unlikely. Exercising personal responsibility, especially when symptomatic, and practising good personal hygiene, remain effective at reducing the risk of transmission of mpox in the general population.

However, we should not be complacent. The situation is evolving and there is still some uncertainty around the disease characteristics. We will learn more about the disease in the coming months and should be prepared to change our plans as we understand the disease more.

Thank you, Mr Speaker. I thank the Minister for his very comprehensive reply. I have a short supplementary question. Does the Ministry have any plans to make the mpox vaccine available and free for vulnerable groups of the population, such as the elderly, who may not have taken the smallpox vaccine previously or immunocompromised patients?

Most older Singaporeans would have taken the smallpox vaccine at birth. I have one. The coverage before 1981 has been very broad – well over 90%. So, if they have not taken for some reason, it could be because it is not suitable for them, in which case, then I think we have to look at the other alternatives. But I think, in general, the mpox vaccine JYNNEOS will be offered free to the two groups I mentioned – healthcare workers who are directly exposed to the virus in taking care of patients as well as post-exposure prophylaxis for close contacts of an infected person. We think this is better use of the stock of JYNNEOS that we have to suppress transmission, as opposed to offering it widely and free to the population, because given the characteristics of this virus with an R of 1.3, I think our method, our vaccination strategy will be more effective, given the stockpile of JYNNEOS that we have.

I thank the Minister for sharing with us the response plans in relation to combating this situation. I wanted to follow up by asking whether the Ministry is planning to implement enhanced surveillance and precautionary measures in close-quarter living environments. I understand from the Minister that there are already some measures in place for places such as preschools, but I want to know what about places such as camps where our Servicemen reside, old folks' homes where vulnerable seniors are situated and foreign worker dormitories as well.

I think closer surveillance will be a good idea in those settings that the Member mentioned and they will be implemented. That means a closer watch-out for symptoms and able to have in situ isolation facilities. So, in all those settings that the Member mentioned, those contingency plans have been developed since COVID-19.

Thank you, Speaker, and thank you to the Minister for his comprehensive reply. I have got three supplementary questions. First, I wish to ask if information will be put out to the population here so that people can be encouraged to quickly seek medical attention immediately if they exhibit symptoms of mpox, so that it can be quickly picked up by our general practitioners (GPs) and medical professionals. On that related note, will the Minister consider a community monitoring and surveillance programme or strategy to detect any cases in the population if the situation becomes serious? Finally, have there been any cases that when undetected or were still under incubation upon entry into Singapore?

Yes to all three. For the first question, I think in the coming weeks and months, especially when we have our first case, we do expect it to arrive at some point, we will have to put out more information for people to watch out. It is not difficult to miss because you will start to get lesions on your skin. And I think people will be quite concerned.

That relates to the second question, what is more important is to educate the general public that when you see such symptoms, please see a doctor. And then, the best community monitoring is still through our network of GPs and family doctors who have been briefed on what to look out for and what are the protocols.

And finally, the answer is yes. Because of a long incubation period, I think it is not practical to detect and be able to isolate people at the borders. Many will be incubating and will go through our checkpoints before they exhibit symptoms and are picked up.

Having said that, remember the main characteristic of this virus that we are dealing with is a R of 1.3. So, while someone is incubating, our memory is always focused on the last crisis and our memory is COVID – someone incubating; no symptoms can spread to 10, 20 people and we have many of those clusters. In this case, it does not look like a virus that exhibits those characteristics. In fact, it is an R of 1.3 which means even if you are incubating, even if you infect someone, it is through very close physical contact. And in Africa, those tends to be their family members, immediate family members that spend a lot of time with you, with physical skin-to-skin touch and physical contact, living together in the same household.