The cheerful female character, who as yet has no name or form, will join the Takalani Sesame show for its third season on 30 September, Reuters news agency reported.

She will have high self-esteem. Women are often stigmatised about HIV and we are providing a good role model

Joel Schneider

Joel Schneider, a senior adviser to the Sesame Street Workshop, said the character would be a "good role model" for the pre-school children the programme aims at.

However, its messages would be "appropriate" - without explicit mention of sex.

South Africa already has one children's show featuring an HIV-positive character, but this will be the first for three to seven-year-olds.

Mr Schneider said that the character would be exported to some of the eight other countries that air the programme, including possibly the United States.

High self-esteem

Mr Schneider made the announcement at the International Aids Conference in Barcelona.

"This character will be fully part of the community," he said.

"She will have high self-esteem. Women are often stigmatised about HIV and we are providing a good role model as to how to deal with one's situation and how to interact with the community."

He added: "We will be very careful to fashion our messages so they are appropriate to the age group.

"What do I do when I cut my finger? What do I do when you cut your finger? That sort of thing."

The show is likely to have an acute resonance in South Africa, where one in nine people are infected with HIV.

In some parts of South Africa, 40% of women of child-bearing age are HIV-positive.

A report at the conference revealed that because of Aids there would be about 20 million orphans in the continent by the end of the decade - almost 6% of Africa's children.