Now, more than a decade later, South Africa is experiencing a measles outbreak - partly because parents decided not to give their children the protective jab.

Parents, mainly affluent and educated, around the world opted not to vaccinate their children against measles out of fear that it may cause autism.

Autism is a lifelong developmental disability which is often most pronounced in an inability to socially interact.

Nearly 2000 South Africans have contracted measles and at least four have died in the current outbreak .

The Department of Health said a "striking feature" of this year's outbreak was the number of "relatively well-off" teens infected who had not been vaccinated.

Dr Lucille Blumberg of the National Institute for Communicable Diseases said the autism theory had played a role in parents opting not to inoculate their children.

"It, in fact, caused huge harm to the programme. There is no scientific basis whatsoever linking autism to the measles vaccine," Blumberg said.

In South Africa, children are usually given the measles jab at nine months and a booster at 18 months. In the private sector, children may be given either the measles vaccination or the three-in-one injection, MMR, which covers measles, mumps and rubella, or both. This gives 95% protection against the highly contagious virus.

Measles, one of the leading causes of child deaths in South Africa, can lead to blindness, deafness and brain damage.

But, despite the warnings, the national director of Autism South Africa, Jill Stacey, said the theory was still widely supported in the autism community.

"I would personally say among the parents it is supported by the majority and among the medical fraternity it is chiefly disputed," said Stacey.

The executive director of the NICD, Professor Barry Schoub, said the autism theory had "spiralled completely out of control", possibly because some parents of autistic children bought into it while trying to find the cause of their children's condition.

• hawkeyk@sundaytimes.co.za