Thousands of American children are being put on homeopathic alternatives to vaccination by practitioners who claim they can prevent measles and “cure” autism, the Guardian has learned.

At least 200 homeopaths in the US are practicing a controversial “therapy” known as Cease that falsely asserts that it has the power to treat and even cure autism. The acronym stands for Complete Elimination of Autistic Spectrum Expression.

The “therapy” relies in part on administering high doses of vitamin C. Advocates falsely say it repairs the harm caused by vaccination – a double untruth as most vaccines are safe and there is no link between vaccines and autism, a condition for which there is no cure.

In addition 250 homeopaths, some of whom also practice Cease, are promoting “homeoprophylaxis” that advertises itself as an “immunological education program”. More than 2,000 American children have been put on the program which claims to build natural immunity against infectious diseases, though there is no scientific evidence that it works.

Parents who opt to follow Cease or homeoprophylaxis are potentially exposing their children, as well as others around them, to life-threatening illness. The implicit message behind both therapies is that vaccines are harmful and should be avoided.

The spread of such ideas, amplified through the proliferation of anti-vaxxer theories on social media, has begun to have a profound impact on public health in the US. Last month the number of measles cases reached a 25-year peak.

According to the Centers for Disease Control and Prevention, 1,001 individual cases of measles have been confirmed in more than 20 states this year alone.

Scientists and public health experts warn that the eruption of measles is clearly connected to the proliferation of “vaccine hesitancy” – an unwillingness by parents to have their children vaccinated that was recently listed by the World Health Organization as one of the top 10 threats to global health.

More than 100 hotspots in which large numbers of children are now going unvaccinated have been identified across the nation. Of those, 15 are in urban areas. Seven of the 15 have experienced measles outbreaks in 2019.

Mayor Bill de Blasio speaks during a news conference on 9 April declaring a public health emergency in parts of Brooklyn in response to a measles outbreak. Photograph: Shannon Stapleton/Reuters

“These measles outbreaks were both predicted and predictable as the anti-vaccine movement starts to affect public health in this country,” said Peter Hotez, professor and dean of the National School of Tropical Medicine at the Baylor College of Medicine. “This is just the beginning – it is a harbinger of a new normal in America.”

Hotez, who has an autistic daughter and who has written a book debunking the false link between vaccines and autism, said of the claims propagated by homeoprophylaxis and Cease: “There are no alternatives to vaccination against measles and there is no cure to autism – so it’s all made up.”

A leading advocate of both programs is Kate Birch, a homeopath based in Minnesota who said she imported homeoprophylaxis into the US in 2008 having learnt about it in Cuba. She has trained 250 practitioners in its thinking, 80 of whom she still supervises.

She added that there are now some 2,000 children across America under their direction.

Birch’s organization, Free and Healthy Children, is constituted as a 501(c)3 public education charity, allowing it to operate free of federal tax. On its website it clearly states its anti-vaccine ideology, proclaiming that its members “are concerned about the alarming incidence of immune system disturbances and developmental delays affecting so many children as a result of the current-day vaccination programs”.

An associated website run by Birch, vaccinefree, claims that “homeopathic remedies can be used preventatively for measles”.

In an interview with the Guardian, Birch said that homeoprophylaxis strengthened children’s immunity to infectious diseases using “nosodes” – homeopathic remedies made from “pathological disease tissue”. They are taken orally in diluted form.

She claimed nosodes were regulated in the US by the Food and Drug Administration (FDA). In fact, the FDA can and does take action against specific homeopathic manufacturers for putting patients at risk, but it does not approve homeopathic products.

The Guardian put it to Birch that the anti-vaccination message of homeoprophylaxis and Cease was contributing to a public health crisis manifested by the spread of measles. She said her work was dedicated to the “betterment of public health by strengthening children’s immune system to infectious disease”.

She added that in her opinion exposing children to infectious disease by leaving them unvaccinated was a good thing. “We need infectious disease,” she said. “The best immunity to childhood infectious disease is through natural exposure and then you have lifelong immunity”.

The last time that the American public relied on “natural exposure” to measles – that is, before the US measles vaccination program began in 1963 – the disease caused untold human suffering. Up to 4 million Americans contracted it each year, of whom almost 50,000 were hospitalized and 500 died annually.

The Guardian asked the FDA to state its current position on both Cease and homeoprophylaxis. The agency did not comment on the two programs specifically, but said in a statement that the “FDA has warned about the use of products labeled as homeopathic because of concerns that they have not been shown to offer clinical benefits in treating serious and/or life-threatening medical conditions, and that they also may cause serious harm.”

The FDA added: “It deeply concerns us when we see preventable diseases such as measles – a life-threatening infection we thought we had eliminated in the US in 2000 – now making a tragic comeback and threatening our communities, despite having a vaccine available that is safe and highly effective. A factor contributing to the measles outbreak is inaccurate and misleading information about vaccines rather than the reliance on accurate, scientific-based information.”