Monkeypox officially touched down in Australia last week and while experts say that there is no need for panic, the public health importance of the virus should not be underestimated – its close cousin Smallpox killed more than 500 million people during the 1900s.
Both cases were found in returned travellers – one from the UK and the other Europe – and in a move reminiscent of the early days of COVID, the Victorian and New South Wales Departments of Health said they are working rapidly to identify close contacts.
Internationally, Monkeypox has recently been reported in the United Kingdom, Spain, Portugal, France, the Canary Islands, the United States and Canada.
The outbreak is the largest outside of Africa and is unusual because human cases do not commonly infect other people.
Australia’s acting Chief Medical Officer, Dr Sonya Bennett, said that any people showing symptoms (which include a blistering rash, fever, chills, muscle aches, backache, swollen lymph nodes, and exhaustion) should go to their nearest hospital, wearing a mask and calling ahead to make sure they can isolate away from others.
“Australian travellers returning from, or going to, countries where cases have been identified, are urged to be aware of the signs of infection and to seek medical help if they think they may be at risk,” Dr Bennet said.
“Whilst a number of the recently identified cases have self-reported as gay, bisexual, or other men who have sex with men, monkeypox has not been described as a sexually transmitted disease, though it can spread through direct intimate contact during sex.”
She stressed that this was not a pattern seen before and that close contact and infectious skin lesions are the likely mode of transmission.
This includes close contact with an infected person or animal, including some rodents – not necessarily monkeys – or with material contaminated with the virus, such as respiratory tract droplets and contaminated bedding.
Associate Professor of Medicine at the University of Queensland and Director of Infectious Diseases at Mater Health Services, Paul Griffin, said that overall, there is a low risk of transmission in the general population as the virus is only infectious when an individual is symptomatic.
“Following an incubation period of around 6 to 13 days, systemic symptoms similar to many other viral infections are usually seen first including fever, headaches, muscle aches and swollen lymph nodes,” Professor Griffin said.
“Skin eruption often follows with a rash that can include flat lesions to larger fluid filled blisters [and] these lesions tend to be concentrated on the face and extremities rather than on the trunk.
“Usually, the disease is self-limiting after around 2 to 4 weeks but can very rarely be fatal.
“There are varying figures quoted for mortality with differences depending on which strain, though fortunately, it seems the strain with the lower mortality of around 1% is the one that is involved in this outbreak.”
The most significant risk is to pregnant women as infection can affect foetal development.
Professor David Tscharke, the Head of Immunology and Infectious Diseases at ANU’s John Curtin School of Medical Research, said that given the already broad distribution in western countries and renewed global travel, “it was almost inevitable that we’d have a case in Australia eventually.”
“Our research shows that the waning of immunity from smallpox vaccination may be contributing to the increasing outbreaks of monkeypox – it is more than 40-50 years since mass vaccination ceased,” Prof Tscharke said.
Historical data shows that smallpox vaccination was nearly 85% effective against monkeypox, but few people under 50 years have ever had it… even fewer in Australia, where mass vaccination was never used.
As the name suggests, Monkeypox was first found in monkeys in Africa in the late 1950’s, with the first human case reported in 1970 in the Democratic Republic of Congo, and since 2017, large outbreaks in Nigeria and DRC have left scientists puzzled over why a previously rare infection is now becoming more common.