NTDs today are a symptom of poverty and disadvantage. Those most affected are the poorest populations often living in remote, rural areas, in urban slums, or in conflict zones. With little political voice, NTDs have a low profile and status in public health priorities. Lack of reliable statistics coupled with the often unpronounceable names of these diseases have all held back efforts to bring them out of the shadows. Although medically diverse, NTDs share features that allow them to persist in conditions of poverty, where they cluster and frequently overlap. Approximately 1.4 billion people—one-sixth of the world’s population2—suffer from one or more NTDs. Conflict situations or natural disasters aggravate conditions that are conducive to the spread of these diseases. Around half of the world’s population is at risk of contracting these infections. The human NTDs are diseases of poverty, trapping the world’s poorest in a cycle of poverty. The global burden of the NTDs is equivalent to at least half of the combined global burden of HIV/AIDS, tuberculosis (TB), and malaria.
Several NTDs are zoonoses—infections that can be transmitted between animal and human hosts. Such infections can be transmitted directly; others are transmitted indirectly either through food and water or by means of a vector. One of the parasites that causes African trypanosomiasis, or sleeping sickness, can infect livestock and wild animals as well as humans and is transmitted by the bite of a tsetse fly. Additional neglected zoonotic diseases (NZDs) such as brucellosis, bovine tuberculosis, and rabies, which are not typically included among the NTDs, profoundly affect impoverished people not only through their direct effects on human health but also by sickening and killing the livestock upon which their livelihoods depend (WHO, 2006).
NTDs and NZDs not only share features that allow them to persist in conditions of poverty, where they cluster and frequently overlap, but they also present common opportunities for effective, integrated, intervention and control strategies. Significant (though imperfect) control measures—including drugs and vaccines, improvements in water and sanitation, and vector control measures, employed singly or in combination—have been developed for most NTDs and NZDs (Hotez and Pecoul, 2010; Spiegel et al., 2010). Policy makers and funding agencies have begun to acknowledge the public health and economic importance of the NTDs and NZDs, leading to increased support for the use of existing tools (such as the mass administration of drugs to combat several NTDs simultaneously) and the development of more effective integrated programs to control, and in some cases eradicate, these neglected diseases of poverty.
The Institute of Medicine’s (IOM’s) Forum on Microbial Threats hosted a two-day public workshop on September 21 and 22, 2010, in Washington, DC, to explore the scientific and policy dimensions of NTDs and NZDs. Through presentations and discussions, workshop participants discussed the origins and impacts of these diseases, both individually and as a collective phenomenon.