An alternative private school where a number of unvaccinated children may have been exposed to measles has not responded to the WA Government's offer of a mobile clinic to immunise vulnerable students.

Key points: Perth school student brings home measles after getting infected in Europe, where there's an outbreak

Perth school student brings home measles after getting infected in Europe, where there's an outbreak Unvaccinated children at the school are being told to stay home

Unvaccinated children at the school are being told to stay home The school has not responded to an offer by the Health Department for a mobile vaccination clinic, despite reports there are hundreds of unvaccinated kids

It has also emerged the institution's administrator previously ran for Parliament on a platform opposing a no-jab, no-play government health campaign restricting childcare placements for unvaccinated children.

A Year 10 student at the Perth Waldorf School — a Steiner school in the southern suburb of Bibra Lake — was diagnosed with measles last week after travelling in Europe, prompting a warning from the WA Health Department.

The school sent a Health Department notification out to parents via a newsletter, advising them to ensure their child was immunised.

It has been reported up to half of the school's 400 students could be unvaccinated, but the school has not released details.

In a statement, the school said it was following Health Department advice to minimise the spread of infection, including advising all unimmunised individuals be kept home for 14 days if they developed the rash.

However the school has not responded to the department's offer of a mobile vaccination clinic to ensure the large number of unvaccinated students are protected.

It has not responded to questions from the ABC.

Perth Waldorf School has been advised to take steps to prevent a measles outbreak. ( Facebook: Perth Waldorf School )

The Perth Waldorf School has children from early childhood to high school. It also runs a weekly baby group for infants up to one year old.

When one of the baby group's organisers was contacted by the ABC, she declined to comment on whether the meetings would continue this week, other than to say Health Department guidelines were being followed.

School administrator opposes non-vaccination bans

The school administrator, Jean-Michel David, ran as an independent candidate for the Victorian Upper House Eastern Victoria Region in 2014.

The school's administrator Jean-Michel David previously ran for Parliament opposing changes to legislation to stop unvaccinated children enrolling in day care. ( LinkedIn: Jean-Michel David )

His platform included opposition to then-proposed changes to legislation to stop unvaccinated children enrolling in kindergarten and day care. He received 49 votes, a 0.01 per cent share of the total.

He wrote an open letter to the Victorian Parliament in 2014 opposing law changes that stopped unvaccinated children being allowed in kindergartens and daycare centres without a medical exemption.

Mr David said he opposed the bill because it appeared "to shift responsibility from the family to the state".

"My concern has naught to do with the effectiveness or otherwise of vaccinations," he wrote.

"Where healthy children are to be legislationally excluded from healthy community engagement and participation, as well as the benefits of early childhood education, or parents exercising their responsibilities penalised, concerns about the direction of government policy needs to be taken up by our own elected representatives.

"It is not for the Government to implement the views of bureaucracies."

Mr David took over at the school in 2016.

The school had 425 students and 44 teachers in 2016. It is part-funded by the State Government, but raises the rest of its funding from grants and school fees.

'Do the right thing', angry doctors urge school

The Australian Medical Association's WA president Omar Khorshid accused the school of being irresponsible.

"It is very concerning that a school would not be interested in making sure its students are protected from measles, particularly when you know you have a high-risk situation with a carrier of measles ... [and] where you've got a couple of hundred kids who are not immune," he said.

"It's very disappointing and I would certainly call on the school to revisit its approach.

"Schools need to take responsibility and even if you have a slightly different view, and have a view on freedoms and choices and so on, you still have a civic responsibility to do the right thing."

Spike in WA measles cases linked to overseas outbreaks

There have been 13 reported measles cases diagnosed in Western Australia so far this year. There were four in 2016 and five in 2015.

How can you tell if you have measles? The first symptoms of measles are fever, runny nose, cough, sore eyes and feeling very unwell

The first symptoms of measles are fever, runny nose, cough, sore eyes and feeling very unwell The rash usually appears 4 days later and often starts on the face, before spreading to the rest of the body

The rash usually appears 4 days later and often starts on the face, before spreading to the rest of the body Occasionally measles has very serious complications such as pneumonia or inflammation of the brain (Source: WA Department of Health)

"The increase in WA in 2017 has been due to a small outbreak related to a non-vaccinated family returning from Indonesia earlier in the year," a Health Department spokeswoman said.

"Other cases have all been acquired overseas as there has been a large outbreak in Europe and ongoing disease in Asia."

The department said measles was highly infectious and any non-immune people exposed to the disease would be at risk.

According to the American Centre for Disease Control, the disease can live for up to two hours where an infected person has sneezed or coughed.

"Infected people can spread measles to others from four days before through [to] four days after the rash appears," the CDC says.

The disease can be fatal in serious cases. According to the CDC, of every 1,000 children who get measles, one to two children will die from it.

Complications can also see people infected develop pneumonia and encephalitis, which can cause deafness and brain damage.