As a career move, leaving a job as senior partner in the India office of management consultants McKinsey & Company to head an Aids non-governmental organisation may seem odd. But this is not just any NGO. Ashok Alexander is the new executive director of the India Aids Initiative, which has been given US$100 million (HK$780 million) by the Melinda and Bill Gates Foundation for preventing the HIV virus - four million Indians are HIV positive - from snowballing into an epidemic. UN estimates say the virus could infect up to 25 million Indians by 2010. From dealing with India's most powerful companies and CEOs, Mr Alexander will soon be working with non-governmental groups and lethargic Indian officials, some of whom are in deep denial about the Aids crisis. 'It was the chance of a lifetime, a chance to make a huge difference,' says Mr Alexander. 'Every percentage point increase in the incidence of Aids works out to roughly five to six million lives, and the graph is going up so we're talking about making a contribution to saving millions of lives. I couldn't miss it.' Although he is still winding up his affairs at McKinsey & Company, Mr Alexander's energy is already flowing into the organisation. His impatience is noticeable. It stems from the knowledge that India will suffer an unprecedented economic, social and human disaster if the virus is not checked. He struggled to control his emotions inside a New Delhi Aids clinic recently when a woman burst into tears because a visiting American doctor gave her a hug; every Indian doctor had kept her at arm's length. Despite the billions of rupees that have been spent on Aids prevention, the virus is running riot. Although no sophisticated analysis has been done yet, a rough way of calculating what India's Aids bill will be is to take US$500 - the annual cost of treating a victim - and multiply it by the number of infected people. The organisation plans to keep out of the numbers game. As Mr Alexander points out, whichever figure you care to take - five million, 10 million or 20 million - the cost of treatment will have a shattering effect. 'We can't afford medical treatment for the victims because the cost rivals what India spends on education or defence. And if you can't treat the victims, the human and social consequences are too painful to contemplate.' The organisation's immediate priority is to create what Mr Alexander calls large partnerships. This means working with corporations, institutions and celebrities that can get the safe-sex message across. The group will also focus on targeting India's mobile population, such as migrant workers and truck drivers, and on trying to eradicate the stigma of Aids and creating awareness. This, Mr Alexander says, is going to be the organisation's toughest challenge. Indians just do not talk about sex or condoms. 'The key question for us is how do you change this mindset and how do you change it quickly?'