An Italian health official has blamed an alarming rise in measles cases on the populist Five Star Movement (M5S), which has campaigned on an anti-vaccination platform and has repeated discredited links between vaccinations and autism.

According to the health ministry, more than 700 cases of the highly contagious disease have been registered so far in 2017, compared with 220 for the same period last year and 844 in the whole of 2016.

The surge in the number of cases follows a drop in the proportion of two-year-olds given vaccinations from 88% in 2013 to 86% in 2014 and 85.3% in 2015 – well below the 95% threshold advised by the World Health Organisation.

In 2015, the M5S proposed a law against vaccinations because of “the link between vaccinations and specific illnesses such as leukaemia, poisoning, inflammation, immunodepression, inheritable genetic mutations, cancer, autism and allergies”.

Writing on his blog the same year, the party’s leader, Beppe Grillo, said: “Vaccines have played a fundamental role in eradicating terrible illnesses such as polio, diphtheria and hepatitis. However, they bring a risk associated with side-effects that are usually temporary and surmountable … but in very rare cases, can be as severe as getting the same disease you’re trying to be immune to.”

The outbreak of measles this year has been mostly concentrated in the wealthy regions of Piedmont, Lazio, Tuscany and Lombardy. Some doctors in these areas have been actively encouraging parents not to give their child the injection. Turin in Piedmont and Rome in Lazio both elected M5S mayors last June.

Ranieri Guerra, the director general for preventive health at the ministry of health, told the Guardian: “People from the M5S say measles is normal, and that every three years we have a peak, so why is it dangerous? Well, I say it’s not normal to have peaks or outbreaks – we are supposed to be a measles-free country.”

Italy’s health minister, Beatrice Lorenzin, issued a strong defence of vaccinations. Photograph: Emmanuel Dunand/AFP/Getty Images

Last week, Beatrice Lorenzin, Italy’s health minister, issued a strong defence of vaccinations in response to the new figures. “The only weapon we have against serious diseases such as measles is vaccination: enough with the false information. There is no correlation between vaccines and autism,” she said.

Andrea Liberati, an M5s official in the Umbria region, said the nationwide rise in measles cases was the result of confusing information.

“It’s not that we’re entirely against vaccines, but the government needs to send out a clearer message; parents are very confused by the contradictory information,” he said. Liberati also claimed: “There is obviously [also] a commercial element to this, and need for big pharma companies to make money.”

Asked in November last year about some of the less mainstream theories the party has supported, M5S MEP Laura Ferrara denied it opposed vaccinations, but said it wanted to urge parents to be more vigilant about which vaccines they gave their children.

Italians’ perception of the safety of vaccinations was heavily influenced by now-discredited claims of a connection between the combined measles, mumps and rubella (MMR) vaccination and autism. In a high-profile case in 2012, a court in Rimini awarded compensation to the family of an autistic child after ruling that the child’s autism was probably caused by the MMR jab, which played into parents’ fears even though the judgment was quashed on appeal three years later.

These fears, combined with a lack of trust in mainstream politicians, have left many parents agonising over whether to vaccinate their children.

Michele Marchesani and his wife struggled to decide whether or not to inject their daughter, now 15, against measles. They eventually agreed not to, a decision influenced in part by the seven years Marchesani, a physiotherapist, had spent working with an autistic boy.

“His parents believed that the autism was caused by the measles vaccination,” he said. “They campaigned and tried to take it to court, but didn’t get anywhere with it ... I would trust the injection more if, say, a friend convinced me it was the right thing to do, but not when it comes from a politician.”

Elettra De Marches, a mother of 16-year-old twins, also shunned the jab. “My children both had measles,” she said. “It’s a manageable disease. There is no need for an injection, it’s just for commercial purposes.”

Initial symptoms of measles include fever, red eyes and sensitivity to light, greyish white spots in the mouth and throat and cold-like symptoms. The measles rash typically appears after two to four days. The disease can be very debilitating, and although most people recover fully, it can have very serious complications, including blindness and death.

The Italian government is striving to address unfounded fears over vaccinations as part of a new strategy focusing on social media.

“The usual institutional lines of communication do not work,” Guerra said. “The value of immunisation needs to be communicated in a language that is easily understood by younger parents, as that is where the biggest concentration of hesitation is right now.

“We’re talking about letting them know what appropriate information they can access, rather than using whatever rubbish is published on the internet – because that’s another issue.”

The government is also looking into ways of prosecuting doctors who actively persuade parents against the jab. “This is unacceptable … it’s close to being a crime,” added Guerra.