“We have never had such a sophisticated arsenal of technologies for treating disease, yet the gaps in health outcomes keep getting wider. This is unacceptable.” This plea to close the gap between rich and poor nations was made last month by Margaret Chan, director-general of the World Health Organization (WHO), in her first major address on primary health care. Few would disagree. The tragedy is that it joins a litany of similar unheeded appeals by WHO directors-general, stretching back almost 30 years.

Today, more than one billion people — one-sixth of the world's population — are affected by tropical diseases, yet the drug 'pipeline' for these neglected diseases is almost dry. Clearly, there is an urgent need to develop and deliver effective new therapies.

There is no shortage of high-quality research into tropical diseases. But the successful translation of basic scientific discoveries into new treatments is a long, complex and expensive process. This is particularly problematic when dealing with diseases that disproportionally affect poor and marginalized populations. Low returns on investment have discouraged drug companies from allocating resources to tackle these diseases. And an academic culture that rewards publications and wealth creation, rather than contributions to practical social good, has exacerbated the problem and widened the 'translational gap'.

Despite recent increases in funding for developing and delivering new drugs, the situation has not noticeably improved for those actively engaged in the fight against neglected diseases. This is because the problem cannot be solved solely by increasing financial resources. Improvements in infrastructure are sorely needed at almost every level, from regulatory-authority involvement to government leadership and research capacity. As is clear from the following pages, bringing scientific innovation out of the laboratory and into the villages is not a simple task, and success will require the cooperation and commitment of numerous institutions, both public and private. Preventing the millions of unnecessary deaths that occur each year from neglected diseases is the goal, and anything less is unacceptable.

We are pleased to acknowledge financial support from the Bill & Melinda Gates Foundation, the Wellcome Trust, the Foundation for the National Institutes of Health, the Special Programme for Research and Training in Tropical Diseases (TDR), the Burroughs Wellcome Fund and the McLaughlin-Rotman Centre for Global Health in producing this Outlook. As always, Nature carries sole responsibility for all editorial content.