GP Connect Clinical Feature from the Communicable Disease Control Directorate, WA Department of Health
Mpox (formerly monkeypox) has recently reemerged in Australia, with more than 500 cases reported since April 2024, mostly in Victoria and New South Wales. Two cases have been reported in Western Australia in the year to date. Unlike the 2022 outbreak which was strongly associated with recent overseas travel, most cases in the current Australian outbreak have acquired their infection locally.
The clade I and clade II outbreaks are different
On 14 August 2024, the World Health Organization (WHO) declared a Public Health Emergency of International Concern for an mpox clade I outbreak in Africa, which appears to be associated with greater severity in illness compared to clade II. To date, only two cases of the clade I strain of mpox have been detected outside of Africa, and all mpox cases in Australia have been the clade II strain.
The clade II mpox outbreak in Australia continues to disproportionately affect men who have sex with men. Although most cases have been sexually acquired, mpox can also spread through other skin-to-skin contact, respiratory droplets in prolonged face-to-face contact, or contact with contaminated surfaces or items such as towels or bedding.
Mpox may be difficult to recognise
Symptoms of mpox can occur up to 21 days after exposure, but usually appear within 7-14 days. Common prodromal symptoms are similar to other viral infections and include fever or chills, lymphadenopathy, headache, myalgia, arthralgia, sore throat and fatigue.
A rash or lesion(s) typically affects the genital or perianal areas but may appear on any part of the body (including inside the mouth). The lesions may appear as macules, papules, vesicles, pustules, ulcers or scabs as they progress through different stages. Refer to the WHO Atlas of mpox lesions for clinical images.
Other symptoms may include pain on urination (urethritis) or rectal pain, bloody stools or diarrhoea (proctitis). Breakthrough infections can occur in fully vaccinated individuals, but symptoms may be atypical or mild (e.g. a solitary lesion).
What should I do if I suspect mpox?
Test for mpox in men who have sex with men (and their sexual partners) who present with a clinically compatible illness, irrespective of travel history or in patients with a recent travel history to Africa who present with a clinically compatible illness. A quick guide has been developed to support primary health care providers. Remember to:
- Wear personal protective equipment, including a surgical mask (or P2/N95 if patient has respiratory symptoms), gloves, disposable fluid resistant gown and eye protection.
- Consider also testing for syphilis, varicella, herpes, molluscum contagiosum or bacterial infection if there is a clinically compatible presentation.
- Notify the pathology laboratory of an arriving specimen so that it can be handled appropriately.
- Advise the patient to stay home and limit contact with others while awaiting results, and to cover lesions with dressings or clothing if needing to leave home for essential activities. Provide them with What to do following a test
- Clean and disinfect surfaces with a viricidal agent after the patient has left the room.
- Notify confirmed or highly suspicious cases within 24 hours to your local Public Health Unit (or call 9328 0553 if after hours).
Seek infectious diseases or clinical microbiology advice if unsure about mpox testing or management.
A free vaccine is available for high-risk groups
Eligibility for the WA government-funded JYNNEOS® vaccine has been expanded, and the following people are now recommended to be vaccinated against mpox:
- all sexually active gay, bisexual or other men who have sex with men (including cis and trans)
- sex workers, particularly those with clients at risk of mpox exposure
- people living with HIV, if at risk of mpox exposure
- sexual partners of the people above
- laboratory personnel working with orthopoxviruses
- health care workers at risk for mpox, such as those working at sexual health clinics.
Mpox vaccination is currently not recommended as a travel vaccination unless the above eligibility criteria are met.
Post exposure vaccination may also be offered to contacts of a mpox case, as determined by public health.
Two vaccine doses are required for optimal protection
Two doses of JYNNEOS® given at least 28 days apart will ensure optimal protection against infection and severe symptoms. Primary health care providers are encouraged to identify and recall at-risk patients who are eligible for mpox vaccination, or who have only received one dose. Booster doses are not currently recommended.
Subcutaneous injection is now the preferred route of administration and has a reduced risk of scarring compared with intradermal injection.
GPs and other primary health care providers in WA can order JYNNEOS® vaccine on the Onelink ordering platform. Visit the WA Department of Health Mpox immunisation page for further information. Further information:
WA Department of Health:
- Mpox (monkeypox)
- Mpox (monkeypox) quick guide for primary healthcare workers
- Mpox resources – communications toolkit
ASHM:
Australian Immunisation Handbook:
ATAGI: