Mpox

Overview

Mpox is a viral disease that is caused by two distinct clades of the monkeypox virus (MPXV), known as Clade I and II. Most common symptoms of the disease are rash and fever. Serious complications or death can occur in medically vulnerable individuals.

Disease epidemiology

Prior to 2022, mpox was primarily reported in parts of Central (clade I) and West Africa (clade II) where it is endemic. Almost all mpox cases occurring outside of Africa were linked to international travel to endemic regions or through imported animals.

2022 – 2023 global outbreak of MPXV clade IIb: In May 2022, cases of mpox caused by MPXV clade IIb were reported concurrently in multiple countries outside of Africa, which were not historically known to be endemic to mpox, including in Singapore. On 23 July 2022, the World Health Organization (WHO) declared the ongoing outbreak of mpox to be a Public Health Emergency of International Concern (PHEIC) due to its global spread. The PHEIC status was subsequently lifted on 10 May 2023 following a global decline in mpox cases and deaths. Nonetheless, mpox continues to be transmitted at low levels globally.

2023 – 2024 outbreak in Africa: In 2023, the Democratic Republic of the Congo (DRC) reported a significant increase in mpox cases and deaths. Unlike the global outbreak associated with MPXV clade IIb, the virus circulating in the DRC is of the endemic clade I, which has thus far only been detected within the African continent. From July 2024, several countries in the region, including those where historically mpox clade I was not endemic, have also reported mpox cases and outbreaks.

On 14 August 2024, the WHO declared that the mpox outbreak in the DRC and the growing number of countries in Africa constitutes a PHEIC. This follows the Africa Centres for Disease Control and Prevention’s declaration of a Public Health Emergency of Continental Security on 13 August 2024. While there is cross-border spread of mpox clade I in parts of Central and East Africa, the clade I outbreak has thus far largely remained within the African continent.

2025 – 2026: On 5 September 2025, the World Health Organization (WHO) ended the second Public Health Emergency of International Concern (PHEIC) declaration for mpox. While mpox remains a public health concern in some settings, WHO has transitioned from emergency response measures towards longer-term disease control efforts.

In February 2026, WHO updated its global risk assessment framework to focus on affected population groups rather than mpox clades, reflecting limited evidence of meaningful differences in transmission between circulating clades and narrowing differences in case fatality rates. WHO currently assesses the global public health risk as moderate for individuals with multiple sexual partners and children in historically endemic areas, and low for all other individuals. Consistent with this approach, WHO emphasises the importance of surveillance, early case detection and timely reporting, and integrating mpox detection, prevention and care into existing sexual health, STI and HIV services.

Get the latest updates on the mpox situation from the World Health Organization (WHO) (opens in new tab) website.

List of affected countries

Get more information from the regions and countries that have reported mpox clade I and II cases from WHO here (opens in new tab).

Local situation update

Please refer to the Weekly Infectious Diseases Bulletin for the number of confirmed mpox cases in Singapore.

To date, all mpox infections detected in Singapore were of either clade Ib or clade IIb infections. No clade Ia/IIa or recombinant clade Ib/IIb cases have been detected locally.

Pathogen(s)

MPXV is a member of the Orthopoxvirus genus in the Poxviridae family. There are two genetic clades: clade I and clade II.

Transmission

Mpox can spread through direct physical contact, including sexual or intimate contact, with skin lesions or body fluids from lesions of an infected person or recently contaminated materials (e.g., clothing or bedding used by an infected person). Mpox can also be spread through close, prolonged face-to-face interaction with someone who has mpox (such as talking or breathing close to one another, which can generate infectious respiratory particles). The virus can also spread from infected mother to baby during pregnancy or birth, or animals to humans (e.g., through a bite or scratch from an infected animal, bush meat preparation, or direct contact with the blood, body fluids, or skin or mucosal lesions of infected animals).

Food (other than bushmeat) has never been identified as being associated with human cases of mpox. Currently, there is also no evidence that food or food packaging is a likely source or route of transmission of the virus. As such, the risk of mpox transmission through food is low. Please refer to the Singapore Food Agency (SFA) (opens in new tab) website for more information.

Incubation period: Typically 6 to 13 days; up to 21 days.

Infectious period: From onset of symptoms until after all lesions have healed and scabs on the skin have fallen off and a fresh layer of intact skin has formed underneath.

Clinical features

Clinical presentations of both mpox clades are indistinguishable and may include:

• Unexplained acute rash

• Fever (>38.5˚C)

• Headache

• Backache

• Swollen lymph nodes

• Muscle ache

• General feeling of exhaustion or profound weakness

• Proctitis

• Urethritis

• Oral or oropharyngeal manifestations including sore throat/dysphagia

Within 1 to 3 days after the onset of fever, infected persons will develop a maculopapular rash. In the classic presentation, this often starts from the face before becoming generalized (centrifugal distribution), including involvement of palms and soles in up to 75% of cases. The lesions progress uniformly to become vesicles (in contrast to a varicella or syphilis rash which appears in various stages of development) and then pustules, before crusting occurs in approximately 10 days, which then spontaneously scab and fall off.

In the global outbreak of clade IIb, clinicians should note that presentation has often been more atypical and variable in terms of order of onset of fever versus rash and extent of dissemination of rash. About 72% of cases report prodromal systemic symptoms (e.g. fever, fatigue, muscle aches). Anal and genital lesions are reported commonly, often painful, and lesions may initially appear quite non-specific.

Atypical features include:

• Only a few or even just a single lesion, lesions which begin in the genital or perineal/ perianal area and do not spread further.

• Lesions appearing at different (asynchronous) stages of development.

• Appearance of lesions before the onset of fever, malaise, and other constitutional symptoms.

• Symptoms may masquerade as other sexually transmitted infections (STIs), and mpox may occur concurrently with other STIs. Patients remain infectious from the onset of fever until the vesicles/ lesions have scabbed over and have separated, with normal skin underneath (re-epithelialisation).

Risk factors

Risk factors include:

• Relevant travel history to affected countries or regions with confirmed cases of mpox or where mpox is endemic

• Contact with infected animals or animal products in areas where zoonotic transmission occurs, including through hunting, preparing, or consuming wild animals

• Close contact with confirmed cases, including sexual or intimate in-person contact with persons in a social or sexual network experiencing mpox transmission

Diagnosis

Mpox infection is diagnosed when MPXV is detected in samples (e.g., vesicles swabs, throat or anal swabs through PCR.

Treatment and management

For majority of cases, supportive care and symptomatic treatment, such as antipyretics for fever, analgesia for pain relief, and preventing complications remains the mainstay of treatment. Mpox is typically a self-limiting illness, and most patients usually recover within two to four weeks, although serious illness and complications may occur especially in vulnerable persons (e.g., young children, pregnant women, or immunocompromised individuals). In severe cases particularly for immunocompromised patients, the use of antiviral tecovirimat may be considered in consultation with an infectious disease specialist.

Please refer to the Joint CDA-NCID Guidance For Clinical Management of Mpox (opens in new tab) for Healthcare Professionals for more details on the clinical management of mpox.

Precaution, prevention, and control

Prevention measures include:

• Observing and practising good personal hygiene at all times

• Washing hands regularly with soap, especially before handling food or eating, after going to the toilet, or when hands are dirty from coughing or sneezing

• Using an alcohol-based hand sanitiser that contains at least 60% alcohol if water is not available

• Avoiding physical, sexual, or intimate contact with persons who are unwell (e.g., those with rash or other lesions) 

• Avoiding sharing common items, such as clothing, towels, bedding, or other personal items that may be contaminated with body fluids

• Practising safe sex, including avoiding high-risk sexual activities such as having multiple sex partners or engaging in casual sex

• Avoiding close contact with persons who have a rash that looks like mpox, particularly in social events such as parties and clubs

• Avoiding feeding or touching animals, especially stray or wild animals, and the consumption of bush meat when travelling

Travellers from countries affected by mpox should monitor for symptoms for 21 days upon their return from these countries. Please refer to Health Advice for Travellers for precautionary measures to be taken when travelling.

Suspect and confirmed mpox cases should be promptly identified, provided with a surgical mask at the earliest opportunity, and segregated from patients in healthcare facilities. Patients requiring hospital admission should be isolated in an Airborne Infection Isolation Room (AIIR) and managed under Airborne and Contact Precautions, regardless of mpox clade, in accordance with existing institutional protocols and prevailing National IPC Guidelines. Healthcare personnel involved in the care of these patients should don appropriate personal protective equipment (PPE), comprising an N95 respirator, fluid-impermeable gown, gloves, and eye protection (i.e. face shield or goggles). Please refer to National IPC Guidelines for Acute Care, Community Hospitals, Primary Care, and Long-Term Care Facilities for more details on infection prevention and control measures for mpox management.

Vaccination

The MVA-BN (Jynneos), a third-generation vaccine indicated for prevention of smallpox and mpox disease, is currently available as Post Exposure Prophylaxis (PEP) for persons who have been identified to be close contacts of confirmed mpox cases. Currently real-world clinical data is being collected, which will determine the level and duration of protection conferred by vaccination, and persons are advised to continue adhering to the recommended precautions against the disease.

In line with international recommendations, mass population-wide vaccination is currently not recommended as a preventive strategy for mpox, as the risk to the general public remains low with disease transmission predominantly via close physical or prolonged contact.

Close contacts of confirmed mpox cases will be offered a single dose of Jynneos as post-exposure prophylaxis (PEP), which should be given as soon as possible and within 14 days from exposure.

The MVA-BN (Jynneos) vaccine is available as pre-exposure prophylaxis (PrEP) for persons identified to be at higher risk of being infected with mpox, such as healthcare workers rendering direct care to mpox cases.

Based on the HSA-approved Product Insert (approval date as of 19 Sep 2025), two doses (0.5 mL each) of Jynneos are to be administered 4 weeks apart. For HCWs who have received smallpox vaccination before or Singaporeans born in or before 1979 (group with assumed smallpox immunity), one dose of Jynneos will be given. This is in view of studies which show that immunity from smallpox vaccination persists and provides some level of protection against mpox.

Notification

Mpox is a notifiable disease under the Infectious Diseases Act.

• Who should notify:

  • Medical practitioners

  • Laboratories

• When to notify:

  • On clinical suspicion or laboratory confirmation

• How to notify:

  • Please refer to the Infectious Disease Notification (opens in new tab) for more information.

• Notification timeline:

  • Within 24 hours

Resources

Please refer to the Weekly Infectious Diseases Bulletin for the number of mpox cases in Singapore.

For more information on mpox, please refer to the  WHO (opens in new tab) and Centers for Disease Control and Prevention (CDC) (opens in new tab) website.

Please refer to the SFA (opens in new tab) website for more information on the risk of mpox transmission through food.

For general travel advisory, please refer to Health Advice for Travellers.

Please refer to National IPC Guidelines for Acute Care, Community Hospitals, Primary Care, and Long-Term Care Facilities for more details on infection prevention and control measures for mpox management.