Australians travelling to three popular overseas holiday destinations may be putting their lives in danger because of contagious deadly measles outbreaks, health experts have cautioned.

Thailand, the Philippines and Madagascar, the east African island where more than 900 have been killed by the highly infectious disease since September, have all been pinpointed as countries where Australian tourists, especially those with babies, could be at risk.

The death toll in the Philippines and Thailand has also soared into the hundreds, while the West too is fighting a resurgence of the disease amid accusations social media is to blame.

A Filipino boy reacts after receiving a measles vaccine during a nationwide response immunisation program at a street in Las Pinas city, south of Manila, Philippines (AAP)

Worried about Australian tourists importing measles back home, NSW Health has urged people travelling overseas to ensure they are fully vaccinated before heading off.

Last week a Sydney woman in her 40s who thought she had been vaccinated as a child became the 14th person in NSW since Christmas to be diagnosed with measles.

"As in this case, most people in their 40s assume they are immune to measles, however if you don’t have documentation of two doses of measles vaccine, it’s smart to have a free shot before you travel," Dr Vicky Sheppeard, Director of the Communicable Diseases Branch at NSW Health, told nine.com.au in a statement.

Current deadly outbreaks in tourist destinations popular with Aussies means the risk for the contagious disease being imported home is "high", according to NSW Health.

Reported cases of measles around the world. (Nine)

A NSW Health spokesperson explained to nine.com.au those destinations included Thailand, the Philippines, Madagascar and to a lesser extent "several European countries".

The epidemic in Madagascar has so far caused more than 900 deaths.

According to World Health Organisation figures, there have been more than 68,000 cases of the disease since the outbreak began in September. There have been 553 deaths confirmed and another 373 suspected from measles.

The death toll in the Philippines has reached 203, according to latest United Nations data. Since 2019, 12,736 measles cases were reported nationwide.

Measles is sweeping rapidly through southern Thailand, with national health authorities recording between 3000-4000 cases, and 22 reported deaths of children. Thais harbouring suspicions about vaccines have been blamed for the spike in cases.

The West is also affected; Public health experts have pointed the finger at a growing distrust of vaccines, claiming misinformation being shared on social media platforms, such as Facebook, is leading people to not immunise.

In the US, where measles was declared eradicated in 2000, 120 cases affecting mostly young children have been recorded across the nation since January.

Japan, with 170 reported cases since the start of the year, is battling its worst outbreak in more than a decade. In Europe, health officials are worried about the rise of measles in the Ukraine and Greece.

An unvaccinated boy from France has just been suspected of reintroducing measles to Costa Rica, after it had been free of the disease for five years.

Some public health experts blame the outbreak on anti-vaxxers who claim on social media that vaccines can cause autism, putting parents off having their children inoculated.

Facebook is expected to take action against the spreading of misinformation about vaccines, a representative from the Silicon Valley giant told CNN .

Mark Zuckerberg delivers the commencement address at Harvard University. (AAP)

The Facebook representative, who asked not to be named, said the social media giant is working with health experts to decide what changes to make and considering a combination of approaches to handle vaccine misinformation.

These approaches wouldn't take misinformation off Facebook but rather make it less prominent.

For example, groups that promote vaccine misinformation wouldn't show up in the list of groups that Facebook recommends users join. Also, Facebook would make sure that posts containing vaccine misinformation would appear farther down in a user's newsfeed.