NTD and NCD Co-morbidities: The Example of Dengue Fever

Recent findings of paradoxically high endemicity of neglected tropical diseases (NTDs) among populations living in the Group of 20 (G20) countries could portend high rates of these diseases among patients with underlying non-communicable diseases (NCDs), with resultant co-morbidities. Today, the G20 countries, together with Nigeria, account for a surprising burden of the world’s NTDs, including approximately one-half of the major helminth infections and almost two-thirds or more of dengue, leprosy, Chagas disease, and leishmaniasis [1,2] as well as tuberculosis [3]. This finding has led to evidence of widespread neglected diseases among the poor who live in proximity to wealth, a concept that has been termed “blue marble health” [1–3]. Additional evidence that 70% of NCDs are also found in the G20 countries and Nigeria [4] suggests the possibility that we should find significant geographic overlap between NTDs and NCDs, especially in the largest middle-income countries such as Brazil, India, Indonesia, Mexico, and China. Ultimately, we can expect to see NTDs occurring among patients with underlying NCDs, and it will be of interest to determine whether unique co-morbidities arise as a result of such a clinical scenario.