Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment

Abstract

In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.

FIG 1

Neglected tropical disease agent taxonomy.

FIG 2

Global intensity map of EReNTD regions of endemicity. Data are from the World Health Organization (2013). We used the following definitions when coding the data for regions of endemicity for each EReNTD according to WHO data: dengue, most of the country is at risk for dengue; rabies, most of the country is at high risk for rabies; Chagas disease, the disease is present in the country; cysticercosis, the disease is reported as endemic in the country; human African trypanosomiasis, the disease is present in the country.

FIG 3

Proposed United Nations “One Health” framework. FAO, Food and Agriculture Organization; OIE, World Organization for Animal Health; TDR, WHO Special Programme for Research and Training in Tropical Diseases; UNDP, United Nations Development Programme; UNEP, United Nations Environment Programme; UNFPA, United Nations Population Fund; UNICEP, United Nations Children's Fund; WHO, World Health Organization; WMO, World Meteorological Organization.