Infectious diseases can be considered “neglected” when there is a lack of effective, affordable, or easy to use drug treatments. As most patients with such diseases live in developing countries and are too poor to pay for drugs, the pharmaceutical industry has traditionally ignored these diseases. Over the past decade, however, the public sector, by creating favourable marketing conditions, has persuaded industry to enter into public-private partnerships to tackle neglected diseases such as malaria, HIV, and tuberculosis. Yet some infectious diseases—the world's “most neglected” diseases—are still being ignored not just by the pharmaceutical industry but also by public-private partnerships.

Why have these partnerships ignored the most neglected diseases, such as kala-azar, Chagas' disease, and sleeping sickness? This question was explored at a recent meeting in New York, organised by Médecins sans Frontières.1 The answer lies in the social contract that exists between the public and private sectors.

The public sector has decided to make it public policy to leave drug development in the hands of the pharmaceutical industry. This industry in turn invests almost exclusively in developing drugs that are likely to be marketable and profitable—drugs for conditions such as pain, cancer, heart disease, and baldness. Public policies, such as tax incentives and …