Public health priority: Urgent.
PHU response time: Respond to any report of mpox disease on day of notification. Enter suspected, probable and confirmed cases on NCIMS within 1 working day.
PHUs should refer to the CDNA Monkeypox virus infection case and contact management guidelines (also detailed below).
Full revision to present evidence-based recommendations for public health.
Revised: The disease, Routine prevention activities, Surveillance objectives, Case management, Specific settings
These interim guidelines describe recommended public health responses to cases and contacts of mpox virus infection. CDNA will continue to review these guidelines as more information becomes available.
Monkeypox virus infection is a nationally notifiable disease.
Urgent: Respond to suspected, probable and confirmed cases immediately (within 24 hours).
Data entry timeline: Within 1 working day for all probable and confirmed cases.
Suspected cases should be notified to the relevant state or territory Public Health Unit (PHU).
When a suspected case has been identified, immediately (within 24 hours):
All probable and confirmed cases should be notified immediately to the relevant state or territory PHU.
When a probable or confirmed case has been identified, immediately (within 24 hours):
Refer to case management for further details on response times and procedures, treatment and exclusion and restriction guidance.
For contacts of probable and confirmed mpox cases:
Refer to contact management for information about physical distancing and other public health measures recommended for medium and high-risk contacts.
On 28 November 2022, the World Health Organization (WHO) announced a change in disease name from monkeypox to mpox. Mpox is caused by infection with monkeypox virus. Mpox virus is an enveloped double-stranded deoxyribonucleic acid (dsDNA) virus of the genus Orthopoxvirus (related to the Poxviridae family), which also includes variola virus (which causes smallpox), vaccinia virus (which is used to produce the smallpox vaccine) and cowpox virus (1).
Mpox virus historically had two distinct genetic clades, the Central African (Congo Basin) clade that caused more severe disease and the West African clade (1, 2). On 12 August 2022, the WHO announced new nomenclature for the mpox virus. The former Congo Basin (Central African) clade is referred to as Clade one (I) and the former milder West African clade as Clade two (II). Additionally, Clade II consists of two subclades, Clade IIa and Clade IIb. Clade IIb refers primarily to the group of variants largely circulating in the 2022 global outbreak (3).
The natural reservoir of mpox virus remains unknown. However, it has been isolated from several African rodents and primates, including the Gambian pouched rat, tree squirrel, rope squirrel and sooty mangabey monkey, marking them as potential reservoirs for the virus (4, 5).
Following the eradication of smallpox in 1980 and subsequent cessation of smallpox vaccination programs, mpox virus has emerged as the most significant Orthopoxvirus for public health. Historically, mpox has primarily occurred in central and west Africa, often in proximity to tropical rainforests (1, 6).
Before 2018, the only cases with transmission outside Africa occurred in the United States of America, in a 2003 outbreak associated with imported rodents from Ghana that infected prairie dogs sold as pets (7, 8). Since early May 2022, mpox transmission has been reported in multiple countries outside Africa, including Australia. Cases notified since 20 May 2022 represent the first time the virus has been detected in Australia (9). The WHO declared the mpox outbreak a public health emergency of international concern on 23 July 2022. On 26 July 2022 (10), Australia's Chief Medical Officer declared mpox to be a Communicable Disease Incident of National Significance (CDINS) – this was announced on 28 July 2022 (11). On 25 November 2022 the national response to mpox was stood down and the declaration of mpox as a CDINS was rescinded.
It has been suggested that the increasing case numbers and geographic spread of mpox in recent years may be related to decreasing population immunity due to cessation of smallpox vaccination programs and increasing urbanisation (12) Smallpox vaccination is protective against other Orthopoxviruses, including mpox (13, 14).
Transmission of mpox virus can occur when a person comes into contact with the virus from an infectious animal or human, or with materials contaminated with the virus (fomites) (15, 16). Transmission occurs through broken skin (even if not visible), or mucous membranes (respiratory tract, conjunctiva, nose, mouth, or genitalia), and may occur though contact with infectious material from skin lesions of an infected person, through respiratory droplets in prolonged face-to-face contact, or through fomites. The highest risk of transmission is associated with direct and close contact, including sexual contact).
Other potential routes of transmission are outlined below.
The incubation period is typically 7 to 14 days, with a range of 5 to 21 days (4, 26, 27). The incubation period may be influenced by the route of transmission, with invasive exposure (e.g. contact with broken skin or mucous membrane) having a shorter incubation period than non-invasive exposure (28).
The infectious period begins with the onset of symptoms, either prodromal or rash. Cases remain infectious until the rash has resolved, and all lesions have formed scabs and fallen off, leaving fresh skin underneath. Cases are not considered infectious prior to the onset of symptoms, however some cases may not be aware of their exact symptom onset date as initial symptoms may be both very subtle and/or not visible (16, 29-32).
Mpox is usually a self-limiting disease with symptoms lasting for 2 to 4 weeks.
The illness may have a prodromal period lasting 1 to 5 days that is characterised by lymphadenopathy, fever (≥38°C) or history of fever, headache, myalgia, arthralgia, back pain and sore throat (33). Not all cases report prodromal symptoms (33).
A maculopapular rash is typical of mpox and may develop 1 to 5 days after the onset of fever. The rash may be generalised or localised, discrete or confluent. It is classically described as centrifugal, more concentrated on the face and extremities than the trunk. Skin lesions often present at first as macules (lesions with a flat base), which progress to papules (slightly raised firm lesions), vesicles (lesions filled with clear fluid) and pustules (lesions filled with yellowish fluid). Crusted scabbing usually begins 14 to 21 days after rash onset. Scabs then fall off, leaving dyspigmented scars (34).
A typical distinguishing feature of mpox (Clade I and IIa), not observed in smallpox or varicella, is the presence of lymphadenopathy such as swelling at the maxillary, cervical or inguinal lymph nodes (35).
However, many cases in the current global outbreak of Clade IIb, have not presented with the classically described clinical picture for mpox (fever, swollen lymph nodes, followed by centrifugal rash) (24). Differing presentations of cases in the current Clade IIb outbreak have been described as follows[1]:
Symptomatic manifestations of mpox can cause severe pain and affect vulnerable anatomic sites; in particular painful proctitis or oral lesions may be the primary presentation. More severe complications of mpox infection include secondary infections including cellulitis, bronchopneumonia, sepsis, encephalitis and infection of the cornea with subsequent scarring and loss of vision. Severe dehydration may occur, secondary to vomiting, diarrhoea and oral lesions preventing adequate hydration (23).
[1] Proportion estimates of specific symptoms in Clade II outbreak cases presented above have been informed by a single study with a small sample size and should be considered accordingly.
Internationally, the mpox case fatality rate globally ranges from 0% to 11%, but there are challenges in accurately estimating this rate (36). The multi-country outbreak in non-endemic countries, which began in May 2022 is associated with Clade IIb. In general, Clade II variants are considered to be milder than Clade I.
The Clade I variant has a case fatality rate (CFR) estimated at 10% (37), Clade IIa has an estimated CFR ranging between 1 and 6% (37, 38), and Clade IIb has an estimated CFR of <1%.
For more information about global mpox case data, including deaths, please see: WHO Emergency situation reports.
In the context of the current outbreak, groups at increased risk of severe disease do not necessarily align with those at increased risk of acquiring mpox. Evidence on severe disease outcomes are limited but occur more frequently among people who are unvaccinated (30).
Immunocompromised individuals, including those with HIV infection that is not well-controlled (CD4 count <200 cells/μL), are also believed to be at higher risk of severe disease (40-42).
Clade I outbreaks have recorded severe outcomes in children, especially children (younger than 10 years). This could be related to the cessation of smallpox vaccination, prolonged close contact with family members or caregivers who are cases and in endemic countries due to malnutrition and co-infections (43-46). Pregnant women and their foetus may also be at increased risk as vertical transmission has been recorded (21).
Anyone who is in very close contact with someone with mpox, particularly where skin-to-skin contact occurs, is at risk. While the mode of transmission means that anyone can acquire or transmit mpox, cases in the current outbreak have occurred primarily, but not exclusively, in gay, bisexual and other men who have sex with men (24, 33, 34, 47).
Cases have sometimes been associated with large events or parties, including festivals in Europe (49).
High-risk settings and activities for transmission in the context of the current outbreak include:
Consideration of the following measures by PHUs may prevent transmission of the monkeypox virus and reduce mpox infections:
Individuals should also consider additional advice to minimise their risk of acquiring mpox,
Mpox is vaccine-preventable. The global supply of vaccines is limited, and vaccination should be prioritised for higher risk priority groups. Both post-exposure preventative vaccination (PEPV) and primary preventative vaccination (PPV) can reduce the likelihood of widespread community transmission.
Refer to ATAGI clinical guidance on vaccination against Monkeypox for advice on specific vaccines available and the Australian Human Monkeypox Treatment Guidelines for advice on the prevention and management of vaccine related complications relating to the second-generation vaccine.
Key surveillance objectives are to:
Confirmed and probable cases should be entered on to the National Notifiable Diseases Surveillance System (NNDSS) by jurisdictional PHUs, ideally within one working day of notification.
The date of onset is the date of symptom onset, which may be prodromal/systemic symptoms, or may be a rash.
Cases subsequently shown not to have mpox should be excluded within one working day.
Multi-jurisdictional outbreaks requiring national coordination may require support from the National Incident Centre (NIC).
For case definitions please see CDNA surveillance case definitions | Australian Government Department of Health and Aged Care.
Before testing, suspected cases should be notified to the relevant state or territory PHU.
Subject to advice from the jurisdictional PHU, patients with symptoms who present with a history suggestive of exposure to mpox should have a specimen collected and be referred for laboratory testing.
Testing is performed at jurisdictional public health laboratories. The testing laboratory may be contacted to arrange receipt of specimens. General advice is outlined in the Public Health Laboratory Network Guidance on Monkeypox patient referral, specimen collection and test requesting for general practitioners and sexual health physicians. Specific advice from the medical microbiologist at the testing laboratory may be sought to obtain advice on specimen collection, safe packaging and transport.
Appropriate personal protective equipment (PPE) should be worn while collecting samples from patients suspected of monkeypox virus infection.
Lesion material should be collected from people with suspected monkeypox virus infection who have an active lesion or rash. Acceptable sample types include lesion fluid, lesion tissue, lesion crust or skin biopsy.
It is advisable to collect samples from more than one lesion where possible, however excessive sample collection should be discouraged to minimise risk to healthcare workers or laboratory personnel.
Lesion specimens are preferred however throat or nasopharyngeal swabs are also suitable specimens. Such specimens may be collected in persons with prodromal symptoms who present with no lesions, e.g., a contact who develops symptoms.
Material should be collected using a sterile dry swab. Avoid using transport medium, as this may dilute the sample and increase risk of leakage. For further advice, including on appropriate PPE and safe handling and transport of specimens, refer to the Monkeypox Laboratory Case Definition.
Urgent: immediately (within 24 hours).
PHUs should begin follow-up investigation for all probable and confirmed cases on the day of notification to identify the source of exposure and contacts.
PHUs should ensure that action has been taken to:
Exclusion and restriction of mpox cases should occur during the presumed and known infectious periods, including the prodromal and rash stages of the illness. Cases should be advised to do the following during their infectious period and until advice has been provided by PHUs regarding clearance of infection.
Until they meet the clearance criteria:
Essential activities:
If a case needs to leave the home for essential activities, they should wear a surgical mask, ensure any rash or lesions are covered, and avoid close contact with others- especially if using public transport.
If cases cannot work from home, PHUs may conduct a risk assessment on a case-by-case basis, to inform whether the case can attend the workplace. Factors to consider include: the type and nature of their work, number and location of their lesions, and mode of transport to and from work.
For example, a person who works primarily in an outdoor setting where physical distancing can be maintained, may be considered as being able to attend work. Those working in a high-risk setting, particularly in a care-giving role, should not attend work.
PHUs should ensure people with mpox have access to a PHU contact number to seek advice or support where required.
Cases can resume normal activity when all lesions have crusted, scabs have fallen off and a fresh layer of skin has formed underneath.
The PHU or managing clinician will advise on clearance of a case.
For 12 weeks following clearance, cases should:
For cases with non-visible skin lesions (e.g., cases with proctitis), it is recommended they follow the case exclusion and restriction requirements above until complete resolution of all symptoms.
International reports of asymptomatic monkeypox virus infection in the current global Clade IIb outbreak are rare and generally only detected and described in research studies. There is limited evidence available to determine whether asymptomatic cases are infectious.
Mpox virus infection is generally a self-limiting infection. Most cases will not require specific treatment other than supportive management or treatment of complications (e.g., antibiotics for secondary cellulitis).
Advice on clinical management should be sought from an infectious disease's physician. If antiviral treatment is indicated, it should be initiated in consultation with an infectious disease physician and/or sexual health physician. Tecovirimat (TPOXX) is the preferred treatment for severe monkeypox virus infection.
For further advice, refer to the Australian Human Monkeypox Treatment Guidelines.
Direct contact2 via intact skin (while case is symptomatic), with potentially contaminated materials (including bed linens and healthcare equipment), crusts, or bodily fluids, while the contact was not wearing appropriate PPE3
or
Indirect contact4 with a mpox case, while the contact was not wearing appropriate PPE3, during any procedure that may create aerosols from oral secretions, skin lesions or resuspension of dried exudates (e.g. shaking of soiled linens, showering patients, or conducting procedures involving the oropharynx)
Indirect contact with a mpox case in a high-risk setting, including higher- risk social settings or situations*, while the contact was not wearing a mask, based on a risk assessment.
Note: Contact tracing of flights, buses and other public transport is not required**
Note: Low risk contacts do not require follow up, but some jurisdictions may choose to do so at their own discretion.
Contacts of probable and confirmed mpox cases should monitor for signs and symptoms of mpox for 21 days after the date of their last exposure. All contacts should be encouraged to practise good hand hygiene and respiratory etiquette.
See Table 2 for detailed guidance on management of high- and medium-risk contacts.
Surveillance: Routine active monitoring1
Post-exposure preventative vaccination (PEPV) administration2:
Testing priority: High if compatible symptoms develop
Additional recommendations:
For 21 days from last exposure:
Post-exposure vaccination: Consider vaccination with MVA-BN following a case-by-case risk assessment.
Testing priority: High if a clinically compatible rash develops; intermediate if compatible prodromal symptoms develop
Low risk contacts do not require follow up.
At their discretion, some PHUs may advise low-risk contacts to self-monitor for signs and symptoms, and if any signs or symptoms occur within 21 days of last exposure, to follow exclusion and restriction advice and report to public health officials.
Note:
In the event a case/s is reported to have attended an SOPV whilst infectious, a PHU may consider the following outbreak management strategies. PHUs should:
Methods of messaging and the ability to contact trace may be limited due to the willingness of patrons to provide contact information. Best practice may require assessment on a case by case basis.
To minimise the risk of an outbreak occurring at an SOPV, venues are encouraged to implement the following preventative measures:
Congregate living settings are facilities or other housing where people who are not related reside in close proximity and share at least one common room (e.g., sleeping room, kitchen, bathroom, living room). Congregate living settings can include correctional and detention facilities, homeless shelters, group homes, dormitories at institutes of higher education, boarding schools, seasonal worker housing, residential substance use treatment facilities and other similar settings, but excludes healthcare settings.
In the event of a case/s in a congregate living setting, PHUs may consider the following outbreak management strategies:
To minimise the risk of an outbreak occurring in a congregate living setting facility, the following preventative measures may be implemented:
If introduction of mpox occurs in an Aboriginal and Torres Strait Islander community, the risk of mpox transmission may be higher than the general community, due to inadequate and overcrowded housing. For this reason, a low threshold should be used to initiate disease control measures, including consideration of communications and broader vaccination strategies. PHUs may consider targeted action to all community members in a remote Aboriginal or Torres Strait Islander community if supported by the epidemiological context. The nature of any action will depend on factors including the size and remoteness of the community. Community engagement should be central to any community-based response and should continue throughout implementation to ensure actions are culturally appropriate.
Workers in healthcare settings should always follow the ICEG interim guidance on Monkeypox for health workers when treating a mpox case. If this guidance is followed appropriately, the risk of transmission between cases and contacts in a healthcare setting is minimal.
Please refer to the NSW specific SoNG appendix for additional advice on management of mpox cases and contacts.