Mpox

Notification requirement for mpox

Mpox is an urgent notifiable condition.

Notify any suspected or confirmed case to the Department of Health by telephone as soon as practicable and within 24 hours by calling 1300 651 160 (24/7).

Medical practitioners do not require approval to test for mpox.

Infectious agent of mpox

Mpox is caused by the monkeypox virus, a poxvirus of the Orthopoxvirus genus in the Poxviridae family.

Monkeypox virus has two distinct genetic clades. Clade I is endemic in central Africa (Congo Basin) and typically causes more severe disease than Clade II, which is endemic in west Africa.

On 14 August 2024, the World Health Organization declared the mpox outbreak in central and eastern Africa a Public Health Emergency of International Concern in the context of an emergent mpox strain, Clade Ib, which is likely to cause more severe disease, and its rapid spread throughout the Democratic Republic of Congo and neighbouring countries.

A subclade known as Clade IIb, has been largely circulating since 2022 in the global mpox outbreak, mostly impacting gay, bisexual and other men who have sex with men (GBMSM). All cases detected in Australia since 2022 have been caused by this clade.

Identification of mpox

Clinical features

Symptoms of mpox can include a rash, swollen lymph nodes, fever, chills, headache, sore throat, muscle aches, joint pain and exhaustion. Non-rash symptoms may precede or accompany the rash. Some people with mpox experience proctitis (which may present with anal or rectal pain, bloody stools, diarrhoea) or urethritis.

Atypical or attenuated clinical presentations can occur particularly in fully or partially vaccinated people.

The rash mainly affects the genital or perianal areas, face, including inside the mouth, and extremities such as hands and arms or feet and legs, however other parts of the body can be affected. The rash may change and go through different stages and involve skin lesions such as vesicles, pustules, pimples, or ulcers which become scabs that fall off.

People may be infectious up to 4 days prior to the onset of symptoms, either prodrome, rash or proctitis. People remain infectious until the rash has resolved, and all lesions have formed scabs and fallen off, leaving fresh skin underneath. For some people, initial symptoms may be very subtle or not visible, which is why clinicians need to have a high index of suspicion for mpox, especially in people with risk factors. People who develop no visible lesions (e.g. those with proctitis) should be considered infectious until complete resolution of all symptoms, or 21 days after symptom onset, whichever is longer.

Symptoms may resemble sexually transmitted infections (STIs). Symptoms of mpox usually begin 3-21 days after exposure. Symptoms typically last for 2-4 weeks. Mpox illness is usually mild, however, some people may develop severe illness and require hospitalisation. Children, pregnant women, and immunocompromised people are considered at higher risk of developing severe disease.

Diagnosis

Clinicians should be aware of the possibility of mpox in all people with compatible symptoms. Mpox may present similarly to other conditions including syphilis, herpes simplex, chancroid, lymphogranuloma venereum, measles, varicella zoster and molluscum contagiosum. Testing for mpox should be considered as part of investigation of differential diagnoses based on individual risk assessment.

Diagnosis is confirmed by polymerase chain reaction (PCR).

Suitable samples include a swab or other specimen of rash lesion material (fluid, tissue, crust or skin biopsy). Other samples can include anorectal swabs for patients presenting with proctitis and nasopharyngeal swabs for oropharyngeal symptoms. Consider taking multiple swabs and write the collection site on the specimen containers. For further testing advice, refer to the Australian STI Management Guidelines or Public Health Laboratory Network (PHLN) guidance.

Sampling procedures may vary depending on the location and phase of the rash or other presenting symptoms, and specific packaging and transport of samples are required. Specimens should be collected using a sterile dry swab. Avoid using transport medium, as this may dilute the sample and increase risk of leakage.

Clinicians should wear appropriate personal protective equipment (PPE) when collecting samples (contact and droplet precautions). This includes fluid repellent surgical mask, gloves, disposable fluid resistant gown, and eye protection – face shields or goggles. For further advice on appropriate personal protective equipment (PPE) and safe handling and transport of specimens, refer to PHLN guidance.

Patients who have been tested or are positive for mpox can be shown this page for more information about mpox and precautions to take: Advice for people with mpox.

Incubation period of mpox

The incubation period for mpox is typically 8 days with a range of 3 to 21 days. Incubation period may be influenced by the route of transmission, with direct exposure (e.g., mucous membrane or broken skin) having a shorter incubation period.

Transmission of mpox

Person-to-person transmission occurs with prolonged physical or intimate contact with infected people (such as skin-to skin contact during sexual contact) and can also spread through respiratory droplets and contact with contaminated surfaces and objects (such as contaminated clothing, towels, or bedding). Vertical transmission from infected pregnant persons and transmission from infected animals (when hunting, skinning, or cooking them) has previously been documented in endemic regions. In the international outbreak of Clade IIb, the highest risk of transmission has been associated with direct and close contact, particularly sexual contact, among GBMSM. Airborne transmission of monkeypox virus is possible but does not appear to be a predominant feature of the Clade IIb outbreak.

Evidence on Clade Ib transmission since it emerged in DRC in September 2023 is limited, but initial reports indicate that transmission is primarily linked to sexual contact, with the highest incidence in adolescents and young adults not involved in sex work, followed by sex workers.

Period of communicability of mpox

People may be infectious up to 4 days prior to the onset of symptoms (which may be a fever or a rash) and until the rash has resolved, and all lesions have formed scabs and fallen off, leaving fresh skin underneath. Some people may not be aware of their exact symptom onset date, as initial symptoms may be subtle or not visible. People who develop no visible lesions (e.g. those with proctitis) should be considered infectious for 21 days after diagnosis or until symptoms resolve, whichever is longer.

Susceptibility and resistance to mpox

Most people are not at risk of mpox.

In recent outbreaks of Clade IIb, in Australia and globally, those most at risk have been GBMSM, particularly those who have multiple sexual partners or attend sex on premises venues, and are travelling to outbreak areas.

People who have previously been vaccinated against smallpox may have some immunity against mpox, however, may still benefit from receiving mpox vaccine.

Control measures for mpox

Preventive measures

In addition to vaccination, mpox can be prevented through various measures, including:

• Avoiding close contact with people with suspected or confirmed mpox. This includes any potentially contaminated materials, such as bedding and towels, that have been in contact with an infected person.
• Maintaining good hygiene practices like washing hands with soap and water or cleaning hands with alcohol-based sanitiser.
• Considering limiting the number of sexual partners during local outbreaks and ensuring that contact details are collected.
• Considering limiting sexual partners for three weeks after returning from overseas countries that have active outbreaks.

For more information for men who have sex with men, visit Thorne Harbour Health website.

Vaccination

In Victoria, the mpox vaccine (JYNNEOS® vaccine) is available free-of-charge for eligible people.

Eligibility criteria

Post-exposure preventative vaccination (PEPV) preferably within 4 days of first exposure, in accordance with clinical guidance from the Australian Technical Advisory Group on Immunisation (ATAGI) for:

• High-risk contacts of mpox cases
• Attendees of sex-on-premises venues and public or private events (particularly where sexual or intimate contact may occur) in areas where local transmission of mpox is occurring.

Eligible people for primary preventative vaccination (PPV) include:

• Sexually active GBMSM.
• Sexually active transgender and gender diverse people, if at risk of mpox exposure.
• Sex workers, particularly those whose clients are at risk of mpox exposure.
• Sexual partners (including anonymous or intimate contacts) of the above groups.
• Sex-on-premises venue staff and attendees.
• People living with HIV, if at risk of mpox exposure, and their partners.
• Laboratory personnel working with orthopoxviruses.
• Vaccination may also be considered for healthcare workers at risk of exposure to patients with mpox, based on local risk assessments. This may include primary care, sexual health clinics, hospital staff and others. The risk of transmission should also be minimised by using infection control measures.

Two doses of the vaccine are required for optimal protection and are provided subcutaneously 28 days apart. The mpox vaccine takes approximately 14 days before it is effective.

Currently, ATAGI does not recommend booster doses of the mpox vaccine for people fully vaccinated with two doses, including those who are severely immunocompromised. ATAGI will continue to review available evidence on whether booster doses should be considered in the future.

Mpox vaccination is not currently recommended for travel unless people are eligible for mpox vaccination in Victoria. For the most up to date travel information, visit Smartraveller.

For more information on vaccination, see the Victorian mpox (monkeypox) vaccination program guidelines and the Australian Immunisation Handbook - Mpox.

How to access the vaccine

Free mpox vaccine is widely available for eligible people through Sexual Health Clinics, GPs, Aboriginal Health Services, public hospitals, community pharmacies and some local councils.

Find your local mpox immunisation provider

To get the mpox vaccine, people can search for a local mpox immunisation provider in their local government area on the Better Health Channel or contact the following sexual health clinics:

• Thorne Harbour Health
• Melbourne Sexual Health Centre
• Prahran Market Clinic
• Northside Clinic
• Collins Street Medical Centre
• Sexual Health Victoria.

Alternatively, people can contact their Local Public Health Unit (LPHU) for further information or assistance with locating their local mpox immunisation provider.

Please note while the vaccine is free, the consultation may not be. Speak to the immunisation provider to verify consultation-related fees and vaccine availability.

Immunisation providers can order the mpox vaccine through Onelink online.

For all other enquiries regarding the mpox vaccine, email immunisation@health.vic.gov.au.

Mpox eLearning module

Online training has been developed to educate immunisers about mpox immunisation and support the delivery of the mpox vaccination program.

Please refer to the Secretary Approvals for pharmacist immunisers and intern pharmacist immunisers, nurse immunisers, and Aboriginal and Torres Strait Islander health practitioner immunisers for information about the scope and requirements of the authorisation.

Access the mpox eLearning module

When to get mpox vaccine

The best time for people to get the vaccine is before they are exposed to mpox. The vaccine takes approximately 14 days before it is effective. Individuals who have been vaccinated should follow public health advice to minimise their risk of contracting mpox during this time.

If a person is exposed to mpox, receiving a vaccination within 4 days after the first exposure will provide the highest chance of avoiding disease.

Anyone at-risk who is planning to travel to a country with a significant outbreak should be vaccinated 4-6 weeks before they depart to allow for maximum protection.

Control of case

Mpox typically results in a mild illness and most cases recover within a few weeks. Most cases will not require specific treatment other than supportive management or treatment of complications (e.g. analgesia for painful lesions or antibiotics for secondary cellulitis).

Antivirals may be indicated for severe infections. Tecovirimat (TPOXX) is the preferred treatment for severe mpox virus infection.

If required, advice on clinical management, including antiviral treatment, should be sought from an infectious disease physician. Approval is required from the Deputy Chief Health Officer to access TPOXX from the National Medical Stockpile. Clinicians should contact the Department of Health on 1300 651 160 to request authorisation.

Patients with confirmed or suspected (until result known) mpox should be advised to:

• Avoid close contact with others, including all sexual activity.
• Cover exposed lesions around others and animals.
• Wear a surgical mask around others if they have oral lesions, pharyngitis, or respiratory symptoms (such as coughing).
• Stay at home if they are unable to cover lesions, wear a mask, or if suspected or confirmed to have a Clade Ib infection.

Cases are no longer infectious when the rash has resolved and all lesions have formed scabs and fallen off, leaving fresh skin underneath. Not all cases have visible lesions (eg. cases with proctitis alone). Cases who do not develop visible lesions should be considered infectious for 21 days after symptom onset, or until symptoms completely resolve, whichever is longer. Symptoms of mpox typically last for 2-4 weeks.

For 12 weeks after recovery, people should use condoms during sexual activity, and not donate human tissue, including blood, cells, tissue, breast milk, semen, or organs.

Patients who have been tested or are positive for mpox can be shown this page for more information about mpox and precautions to take: Advice for people with mpox.

Local Public Health Units (LPHUs) will provide specific advice to cases regarding requirements to restrict interactions and follow precautions.

Control of contacts

Depending on the level of exposure, LPHUs may follow up contacts to advise them of their exposure, to monitor for symptoms, and follow precautions for 21 days following exposure. Contacts may be recommended to receive post-exposure prophylaxis to reduce their risk of infection.

Post-exposure prophylaxis

Vaccination with an mpox vaccine or other post-exposure prophylaxis (including vaccinia immunoglobulin) may be recommended for certain contacts after a risk assessment, if there are no contraindications.

Post-exposure vaccination should be given preferably within 4 days of exposure to mpox but can be given up to 14 days after last exposure based on a risk assessment. Contacts eligible for PEP will be referred by their LPHU to a health service for vaccination.

Resources for health professionals

The Australian Immunisation Handbook - Mpox

Community resources