In August 2024, the World Health Organization (WHO) once again declared mpox a global health emergency, marking the second time the virus has triggered such an alarm since its initial outbreak between 2022 and 2023.
This time, the crisis is fueled by a more aggressive variant known as Clade I, which is more virulent than the Clade II variant that caused the first wave of infections.
The resurgence of mpox has led to new cases being reported across several countries, with a significant rise in The Democratic Republic of the Congo and other parts of Africa. In the past year alone, Congo has recorded over 1,200 new cases. Other African nations, including Nigeria and the Central African Republic, are also seeing an uptick in infections, with more than 3,000 cases reported across the continent since the recent outbreak began.
Singapore has not yet reported a significant outbreak, but the global health emergency status requires close attention and proactive measures.
Dr Adrian Ong, infectious disease specialist at Mount Elizabeth Hospital, answers frequently asked questions about the disease and what you can do to protect yourself from getting infected.
1. What is mpox?
Mpox, previously known as monkeypox, is a viral illness caused by the mpox virus, part of the same family as the smallpox virus. It typically begins with symptoms such as fever, rash, and swollen lymph nodes, followed by a distinctive rash that develops into pus-filled lesions. The mpox virus is classified into two main clades: Clade I and Clade II.
Clade I, primarily found in Central Africa, is more virulent, causing more severe disease and higher mortality rates, while Clade II, which includes subtypes IIa and IIb, was responsible for the global outbreak in 2022 and 2023. Clade II is generally milder and less infectious.
2. What are common symptoms of mpox? How soon do they appear after infection and how long do symptoms last?
Symptoms of monkeypox show up within one 1 – 2 weeks of exposure to an infected animal or human, with many patients reporting symptoms such as:
- Fever
- Fatigue
- Swollen lymph nodes
- Headache
- Body ache
- Muscle ache
- Skin rash
Fatigue and body aches are often followed soon after by a widespread rash. The rash is distinctive, resembling small fluid-filled blisters that appear on the face, palms and soles of the feet and even the insides of the mouth. It develops and goes through various stages before forming a scab.
Without treatment, monkeypox is a self-limiting condition with symptoms resolving spontaneously within 14 – 21 days.
3. How is mpox transmitted?
Mpox primarily spreads through close physical contact.
For example, mpox can spread through direct contact with the skin lesions or bodily fluids of an infected person, so avoid close contact with individuals who have symptoms. This includes activities like touching, kissing, or having sexual intercourse with someone who is infected.
4. Are there any differences in the way the Clade 1b variant is transmitted compared to other variants?
Yes. Whereas Clade II was mainly spread sexually, Clade 1b has demonstrated to be more transmissible. During the Clade 1b outbreak in Central and Western Africa, besides the sexual route, sustained person-to-person spread has occurred through household contact and also within the health care setting.
5. How is mpox diagnosed?
Human mpox should be first suspected in persons with an unexplained fluid-filled rash and relevant risk factors such as travel, as well as close and prolonged contact with an infected person. The disease itself can be diagnosed and confirmed through laboratory testing of the fluids from the blisters or rash.
6. How is mpox treated?
As the disease is mild and self-limiting, the vast majority of current mpox patients do not require specific treatment, save for medication to relieve the symptoms.
Patients who experience severe symptoms from the disease, however, can count on antiviral remedies. These antiviral agents are presently approved for use against other viral diseases including smallpox but are expected to be effective for monkeypox as well.
7. Is mpox deadly?
Mpox can be deadly, particularly depending on the clade of the virus and the health status of the individual infected.
Clade I, found primarily in Central Africa, has a higher mortality rate, with a case fatality ratio (CFR) that can reach up to 10%, according to recent reports from public health sources. Clade II, which was responsible for the 2022 – 2023 global outbreak, generally has a lower CFR, ranging from 0.1% – 3.6%.
Clade Ib is a newly identified variant within Clade I, which has been observed to exhibit increased transmission, particularly in certain regions of Africa. While not as widespread globally as Clade II, Clade Ib has raised concerns due to its potential for higher virulence and spread, similar to other Clade I strains. This variant is being closely monitored as it may pose a significant public health threat if it continues to spread beyond its current regions.
8. Does mpox cause long-term health problems or post-infection complications like those seen with other viral infections like COVID-19?
No. Currently, most cases have been self-limiting with the symptoms lasting from 2 – 4 weeks. However, some patients may develop complications or severe disease.
9. Can past vaccinations against smallpox protect us from mpox?
Symptoms of monkeypox resemble that of smallpox, albeit in a much milder form.
In those who had previously been vaccinated against smallpox, the vaccine is thought be durable and long-lasting. In addition, it confers cross-protection of 85% and helps prevent and relieve symptoms of the human monkeypox infection.
However, many young people have never received the smallpox vaccine as routine smallpox vaccination was stopped in the late 1970s and 1980s. Singapore officially ended smallpox immunisation in 1982.
10. Is there a vaccine for mpox? Do I need one?
In Singapore, we have access to highly effective vaccines that not only protect against mpox infection but also help stop its spread.
If you test positive for mpox, it’s crucial to inform your contacts right away so they can receive post-exposure vaccination.
Currently, the Ministry of Health (MOH) in Singapore’s current vaccination approach focuses on persons at high risk of infection, such as close contacts of mpox cases. MOH is monitoring the situation closely and will adjust our vaccination strategy accordingly. For now, population-wide mpox vaccination is not recommended.
For the latest updates on Singapore’s precautionary measures against mpox, please refer to MOH’s website.
11. Who is at greater risk of getting infected with mpox?
Mpox can affect anyone, but certain groups face a higher risk:
- Individuals with close contact: The virus spreads through close physical contact with an infected person or their bodily fluids. This places those in close quarters, such as family members or healthcare workers, at increased risk.
- Travelers: People traveling to or from regions experiencing active outbreaks should be particularly cautious. Given Singapore's international connectivity, travelers should stay alert to potential risks and follow recommended precautions.
- Immunocompromised individuals: Those with weakened immune systems, including individuals with chronic health conditions or those undergoing immunosuppressive treatments, are at higher risk for severe disease.
- Children: With the current outbreak, children have become a more affected group due to factors such as higher transmission rates and changes in the virus’s behavior.
12. Are there particular populations that may be at higher risk for severe illness or complications from mpox?
Yes. Historically and in the current 2024 epidemic, severe disease is more often seen in 2 main categories – young children and those with underlying immune deficiencies such as HIV disease.
13. How can we manage our risks of being infected with mpox?
To protect yourself and others, consider the following precautions:
- Practise good hygiene: Regular handwashing with soap and water, or using hand sanitizers, is essential. Avoid touching your face, particularly the eyes, nose, and mouth.
- Avoid close contact: Minimise physical contact with individuals showing symptoms of mpox. If you are a healthcare worker or caregiver, use appropriate personal protective equipment (PPE) as advised.
- Stay informed: Keep updated with information from local health authorities and the WHO. Adhere to any travel advisories and public health guidelines.
- Seek medical advice: If you develop symptoms such as fever, rash, or swollen lymph nodes, or if you’ve had recent contact with someone diagnosed with mpox, seek medical attention immediately. Early diagnosis and treatment are crucial.
14. Is mpox similar to chickenpox? What is the difference?
Monkeypox and chickenpox have very similar sounding names but are caused by unrelated types of viruses – the monkeypox virus and varicella respectively. While both diseases could cause fluid-filled blisters, they can be distinguished clinically by features such as the pattern of rash and lymph node swelling.
15. What are the current cases of mpox in Singapore?
As of August 2024, all infections detected in Singapore have been the milder Clade II infections.
The new, deadlier Clade 1b variant of the more virulent Clade I strain has alarmed global health experts due to its ability to spread easily through routine close contact, including sexual contact.
For the latest updates on the mpox situation in Singapore, please refer to MOH’s website.
16. Will mpox spread as widely as COVID-19? Is it as contagious?
This is thought to be extremely unlikely, given the difference in transmission patterns between the two diseases.
Mpox mainly requires close and prolonged contact with an infected person or animal to spread, which stands in contrast to COVID-19 that is efficiently transmitted through air-borne aerosols.
While research to understand more about the disease is still underway and the risk of human-to-human transmission is low, it pays to be aware about the symptoms of the disease and how to keep yourself and your loved ones safe.
Should you experience symptoms of mpox, do not hesitate to book an appointment with your healthcare provider to get an accurate diagnosis and begin the treatment you need.
The global health emergency declaration for mpox serves as a reminder of the need for proactive health measures. By staying informed, practicing good hygiene, and taking appropriate precautions, we can help control the spread of mpox and protect public health.
