Travellers to Thailand and Vietnam are being warned about measles outbreaks. (ABC News: Lauren Day)
In short:
Measles cases detected in Australia have been linked to outbreaks in South-East Asia.
Vietnam and Thailand have recorded thousands of infections in 2024, a sharp increase from the dozens recorded in 2023.
What's next:
The Measles, Mumps and Rubella (MMR) vaccine is free and available to most people in Australia, and travellers are encouraged to check their vaccination status.
A surge in measles in South-East Asia is bringing cases of the highly infectious disease to Australian shores, prompting warnings from health authorities.
Vietnam and Thailand are experiencing measles outbreaks, with health professionals concerned about vaccination rates against the disease.
In a health alert issued in Victoria on Saturday, acting chief health officer Dr Evelyn Wong said four recent cases in the state had been linked to travel from South-East Asia.
"There has been an increase in notified cases of measles in returned travellers across Australia in recent weeks," the Victorian health alert said.
"Measles is a highly infectious viral illness that can lead to uncommon but serious complications, such as pneumonia and brain inflammation (encephalitis)."
New South Wales and Queensland also issued health alerts for measles on December 24.
Measles can cause severe complications, such as pneumonia and swelling of the brain. (Reuters: CDC)
In Vietnam, the health ministry reported a whopping 130-fold increase in measles cases in 2024 compared to the previous year.
There were 6,725 confirmed cases and 13 fatalities, according to state media reports.
Most of the fatalities were in children or elderly people with underlying health conditions.
According to data from the World Health Organization, Thailand had 7,507 cases in 2024, compared to just 38 in 2023.
Measles cases in Thailand are more prevalent in the south, where vaccination rates are lower. (Reuters:Â Challinee Thirasupa)
What are measles symptoms?
"Measles is a very nasty infection," said Dr Sanjaya Senanayake, an associate professor at the ANU School of Medicine.
"It is thought to be our most infectious communicable disease."
The World Health Organization says one measles patient can infect nine out of 10 of their unvaccinated close contacts.
It lingers in the environment for around two hours, and a person with measles remains contagious for more than a week, and symptoms may not appear until seven to 18 days after exposure.
"During outbreaks in low vaccination areas, it spreads like wildfire," Dr Senanayake said.
Measles causes a red, itchy rash. (Supplied: Centre for Disease Control)
It's a viral infection with symptoms including:
- fever
- cough
- conjunctivitis (red and sore eyes)
- runny nose
- rash
While the early symptoms are vague and could be mistaken for other illness, in about four days the tell-tale red spotty rash will emerge, starting at the head and neck before spreading to the rest of the body.
While many people will feel unwell and then recover, measles can lead to complications, such as ear infections and pneumonia, especially in children and immunocompromised adults.
Dr Senanayake said it can also cause severe diarrhoea that can lead to dehydration and death, particularly in the developing world, and also brain infection (encephalitis) in about one in 1,000 cases.
Dr Sanjaya Senanayake says measles is one of the most infectious diseases in the world. (ABC News)
He said there's also a rare but fatal type of brain infection called SSPE, which can occur about seven years after a measles infection.
"And that's completely untreatable and a horrible infection — you just die from that."
What's behind the outbreaks?
Measles is preventable, with two doses of the vaccine providing 99 per cent protection.
The COVID pandemic derailed other vaccination programs. (Reuters: Soe Zeya Tun)
Angela Webster, a professor of clinical epidemiology at the University of Sydney, said several countries had eliminated or almost eliminated measles before the COVID-19 pandemic came along.
Professor Angela Webster says travellers should check they are vaccinated against measles. (Supplied: Angela Webster)
"Because of the suspicion of many regular immunisation programs and because of the disruption caused by the pandemic, it meant there's a couple of [cohorts] of particularly younger children who didn't receive the usual vaccinations of childhood," she said.
That made them much more vulnerable to infection.
Du Tuan Quy, from Ho Chi Minh City Children's Hospital 1, said most of the children they treated were not vaccinated or incompletely vaccinated.
"This is a very concerning issue," he told VietNamNet Global, a news outlet aligned with the country's ministry of information.
The article suggested around 10 per cent of the parents of measles patients at the hospital feared the vaccine could have side-effects like autism — a long-debunked piece of misinformation.
"Certainly that misinformation that is out there," Professor Senanayake said.
"There's no doubt in my mind that what happened with COVID and COVID vaccines and vaccine conspiracies just has escalated exponentially that issue."
Measles epidemic
Photo shows Fa'auuga funeral
The Bangkok Post reported in September that Thai authorities organised a vaccination drive after five fatalities in its southern provinces, where vaccine rates were typically lower — just 40-50 per cent, compared to 80-90 per cent nationally.
Dr Thongchai Keeratihattayakorn, director-general of the Department of Disease Control (DDC), told the Bangkok Post the situation at the time was "very worrisome".
He said some parents were concerned side effects like fever could lead to them taking time off work to care for their child and a loss of income as a result.
Measles can spread easily at times of heightened global travel. (AP: Hau Dinh)
In lower-and middle-income countries, vaccine coverage is not as comprehensive and programs are not as well resourced, Professor Webster added.
Professor Webster pointed out both Thailand and Vietnam have high populations and thriving tourist industries.
She said that measles can spread easily at this time of high travel, after Christmas and New Year, with summer holidays in Australia, and Lunar New Year (known as Tet in Vietnam) approaching later this month.
Vietnam and Thailand are popular travel destinations for Australians. (Supplied: Flickr/Bryon Lippincott)
Some media reports from Vietnam suggested authorities were mulling whether to begin vaccination from six months instead of nine months, due to infections in babies.
Health departments in Thailand and Vietnam were contacted for comment.
Push for vaccination
In Australia, the Measles, Mumps and Rubella (MMR) vaccine is free and available to everyone born after 1965, regardless of Medicare eligibility.
The exceptions are for those who are pregnant or with low immune systems, as it is a live vaccine.
Those born before 1965 likely have immunity from when the virus was circulating in Australia.
Measles can be deadly in unvaccinated children. (Supplied: WA Department of Health)
Typically children in Australia will receive the vaccine at 12 and then 18 months.
But for migrants or those who are unsure if they've had the vaccine, or do not have documentation for it, health experts say it's a good idea to get vaccinated — especially if travelling to a country where outbreaks are occurring.
Professor Webster said because vaccination rates have slipped, people were more vulnerable but didn't realise it.
"They've been protected from understanding how serious measles is because it's been so well controlled for so many years," she said.
Dr Senanayake said it was worth travellers checking the measles situation in destination countries and making sure they were vaccinated.
"We've seen outbreaks in a number of other countries around the world, so I don't think we're anywhere close to seeing the end of measles yet," he said.
"But from an individual point of view, it's completely preventable … vaccination is key."