Mpox: Public Health Emergency of International Concern
23 August 2024
The disease mpox is caused by the monkeypox virus (MPXV). The current outbreak of clade Ib mpox in several African countries has been declared by the World Health Organization a Public Health Emergency of International Concern (PHEIC). A global outbreak of clade II mpox began in 2022, with most cases associated with gay, bisexual, and other men who have sex with men. Clade Ia (circulating in parts of Africa) appears to be more severe and spread more easily than clade II, but severity of clade 1b is uncertain. Clade I has not been detected in Australia. The risk of importation of clade Ia and clade Ib to Australia is assessed as low and moderate, respectively. In Australia, there have been 306 cases of mpox notified in 2024, with 4 cases in SA.
Mpox causes a maculopapular body rash that may lead to vesicles and pustules. Systemic symptoms may occur before or after the rash and can include fever, malaise, headache, myalgia and lymphadenopathy. Most cases self-resolve within two to four weeks. The incubation period is 4-21 days. Immunocompromised and pregnant persons, and infants and young children, are more at risk of severe disease. Mpox can occur in people who have been fully vaccinated using 2 doses of smallpox vaccine, however the illness tends be milder. Mpox is spread directly from close contact with lesions, and via body fluids e.g. during sexual contact. It can spread indirectly through contact with contaminated materials, e.g. bed linen and respiratory droplets.
Doctors are reminded to:
- Offer vaccination, to those eligible in SA. Note that the eligibility criteria have been updated. Encourage eligible patients who received one dose of the JYNNEOS vaccine more than 28 days ago to receive the second dose as soon as possible. Clinicians may order mpox vaccine from the Communicable Disease Control Branch (CDCB) and offer to patients directly. For more information visit the SHINE SA and Adelaide Sexual Health Centre websites.
- Consider mpox in individuals with compatible clinical features including a rash or other lesions that could be consistent with mpox, such as proctitis or anogenital lesions.
- Counsel patients who are planning travel to affected countries, particularly those at risk of severe disease. See NSW Health travel advice.
- Consider mpox in individuals with compatible clinical features including a rash or other lesions that could be consistent with mpox, such as proctitis or anogenital lesions. Have an especially high index of suspicion for mpox where there is recent travel or contact with a known or suspected case.
- Arrange testing for any case with compatible clinical features. Wearing PPE, collect two Cobas PCR swabs (which inactivate the virus) from distinct sites (preferably lesion swabs). If you do not have access to a mpox test kit, use dry swabs or swabs in viral transport media. Document “?mpox” on the request.
- Discuss suspected cases with your local infectious diseases (ID) specialist. Antivirals are available through ID for those at risk of severe disease. See Australian Human Monkeypox Treatment Guidelines
- Notify suspected cases to CDCB urgently by phoning 1300 232 272 (24 hours/7 days). Public health follow-up of cases of mpox is coordinated through CDCB.
- Wear appropriate PPE in healthcare settings: P2/N95 mask, gloves, gown, and eye protection. Isolate cases in a negative pressure room, or if unavailable, a single room. In healthcare settings, transport and movement of the patient outside of the room should be limited to medically essential purposes; if the patient is transported outside of their room, they should use well-fitting source control (e.g., medical mask) and have any exposed skin lesions covered with a sheet or gown.
Dr Louise Flood – Medical Lead, Communicable Disease Control Branch (CDCB)