I hope that one day influential religious leaders, cricket players, film stars speak out about Aids

Peter Piot, UNAids

The huge population of India means that while the number of cases is massive, the proportion of adults affected is tiny in comparison.

There are currently 3.8m infected adults in India, compared to 4.7m in South Africa.

However, this is just 0.7% of the population, compared to 20% of adults in South Africa.

The Indian government has launched a nationwide programme to prevent the spread of the disease.

Rural cost

However, there is still an enormous stigma attached to the illness among India's billion-strong population.

The infection is rife in large areas of rural India, having spread from urban areas and high risk groups such as prostitutes.

In some states, such as western Maharashta, as many as 2% of the adult population is HIV positive.

Mr Piot said that some states, such as Uttar Pradesh and Bihar in the east of the country were particularly vulnerable because of their large migrant populations.

He said: "As long as Aids is considered a matter for doctors only, we can forget it.

"It's important to break the silence around it.

'Dangerous illusion'

"I hope that one day influential religious leaders, cricket players, film stars speak out about Aids and are not ashamed to have their names associated with Aids."

Mr Piot said: "For a long time, there's been a denial that the problem is there or that it can affect all levels of the population.

"There's still a perception that it is something for the very poor, homosexual men and drug users.

"People say: 'I'm not like that, therefore I can't get it.'

"That's a very dangerous illusion."

Aids has become the fourth biggest killer worldwide, with an estimated 40m carrying the virus.