NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Friday, January 2, 2015

Neglected Tropical Diseases (NTDs) are a group of 18 infectious diseases – caused by parasites, viruses, or bacteria – that disproportionately affect the poor and cause significant health and financial burdens. NTDs are endemic – meaning that they regularly infect humans – in 149 countries, with over 1 billion people infected and 2 billion people at risk. These diseases are largely treatable and preventable through control of the insects that carry these diseases, improved water quality and sanitation, and the efficient delivery of drug treatments already donated by major pharmaceutical companies. The control and elimination of NTDs cuts across the United Nations’ eight Millennium Development Goals for 2015. Controlling NTDs would not only reduce disease burden but would also improve maternal health, reduce childhood mortality, reduce malnutrition, improve school attendance, and help to empower women. With just a year left on the Millennium Development Goals clock and these diseases still constituting a major burden, we are at a pivotal time for infectious diseases and global health. By defining a clear way forward in the post-2015 development era, we stand to make major progress toward the control, elimination, and eradication of NTDs and other diseases.

What are Neglected Tropical Diseases?

The World Health Organization (WHO) prioritizes 17 neglected tropical diseases (NTDs) (Figure 1) that affect over a billion of the world’s poorest people and pose a significant economic burden to developing economies (scabies was just added to the list in June of 2014, bringing the count to 18). NTDs are a heterogeneous group of infections caused by parasites, viruses, and bacteria. What makes NTDs different from non-neglected diseases is that these diseases are disablers rather than killers. Indeed, these infections are co-endemic: an individual may be infected with more than one NTD in addition to other well-known diseases such as HIV, tuberculosis, and malaria. For example, the parasite infection schistosomiasis can make women and girls more susceptible to HIV infection, saps micronutrients and iron from developing children to stunt their growth, and renders children less likely to attend school. A chronic helminth parasite infection known as lymphatic filariasis (LF) may reduce vaccine efficacy by broadly modulating the immune system. LF causes severe swelling (lymphedema) in 40 million people rendering them socially stigmatized and largely unable to work. In addition to schistosomiasis and LF, many more NTDs are characterized by chronic disabilities, increased susceptibility to infectious and non-infectious diseases, social stigma, and an economic burden on the individual, the family, and the country.