The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

et al. (2014) The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases. PLoS Negl Trop Dis 8(7): e2865. doi:10.1371/journal.pntd.0002865 The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases Peter J. Hotez 0 Miriam Alvarado 0 Mara-Gloria Basa n ez 0 Ian Bolliger 0 Rupert Bourne 0 Michel Boussinesq 0 Simon J. Brooker 0 Ami Shah Brown 0 Geoffrey Buckle 0 Christine M. Budke 0 He le` ne Carabin 0 Luc E. Coffeng 0 Eric M. Fe` vre 0 Thomas Fu rst 0 Yara A. Halasa 0 Rashmi Jasrasaria 0 Nicole E. Johns 0 Jennifer Keiser 0 Charles H. King 0 Rafael Lozano 0 Michele E. Murdoch 0 Simon O'Hanlon 0 Se bastien D. S. Pion 0 Rachel L. Pullan 0 Kapa D. Ramaiah 0 Thomas Roberts 0 Donald S. Shepard 0 Jennifer L. Smith 0 Wilma A. Stolk 0 Eduardo A. Undurraga 0 Ju rg Utzinger 0 Mengru Wang 0 Christopher J. L. Murray 0 Mohsen Naghavi 0 Nilanthi de Silva, University of Kelaniya, Sri Lanka 0 1 National School of Tropical Medicine at Baylor College of Medicine , Houston , Texas, United States of America, 2 Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, Texas, United States of America, 3 James A. Baker III Institute at Rice University , Houston , Texas, United States of America, 4 Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America, 5 Imperial College London , London , United Kingdom , 6 Vision and Eye Research Unit, Anglia Ruskin University , Cambridge , United Kingdom , 7 Institut de Recherche pour le De veloppement, Montpellier, France, 8 London School of Hygiene and Tropical Medicine , London , United Kingdom , 9 Inovio Pharmaceuticals , Inc., Blue Bell, Pennsylvania, United States of America, 10 Johns Hopkins University Bloomberg School of Public Health , Baltimore , Maryland, United States of America, 11 Texas A&M University, College Station, Texas, United States of America, 12 University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America, 13 Erasmus MC, University Medical Center Rotterdam , Rotterdam , Netherlands , 14 Institute of Infection and Global Health, University of Liverpool , Liverpool , United Kingdom , 15 International Livestock Research Institute , Nairobi , Kenya , 16 Swiss Tropical and Public Health Institute, Basel, Switzerland, 17 University of Basel, Basel, Switzerland, 18 Brandeis University , Waltham , Massachusetts, United States of America, 19 Case Western Reserve University , Cleveland , Ohio, United States of America, 20 Watford General Hospital , Watford , United Kingdom , 21 Vector Control Research Centre , Pondicherry , India , 22 Stanford University School of Medicine , Stanford, California , United States of America - The publication of the Global Burden of Disease Study 2010 (GBD 2010) and the accompanying collection of Lancet articles in December 2012 provided the most comprehensive attempt to quantify the burden of almost 300 diseases, injuries, and risk factors, including neglected tropical diseases (NTDs) [13]. The disability-adjusted life year (DALY), the metric used in the GBD 2010, is a tool which may be used to assess and compare the relative impact of a number of diseases locally and globally [46]. Table 1 lists the major NTDs as defined by the World Health Organization (WHO) [7] and their estimated DALYs [1]. With a few exceptions, most of the NTDs currently listed by the WHO [7] or those on the expanded list from PLOS Neglected Tropical Diseases [8] are disablers rather than killers, so the DALY estimates represent one of the few metrics available that could fully embrace the chronic effects of these infections. Even DALYs, however, do not tell the complete story of the harmful effects from NTDs. Some of the specific and potential shortcomings of GBD 2010 have been highlighted elsewhere [9]. Furthermore, DALYs measure only direct health loss and, for example, do not consider the economic impact of the NTDs that results from detrimental effects on school attendance and child development, agriculture (especially from zoonotic NTDs), and overall economic productivity [10,11]. Nor do DALYs account for direct costs of treatment, surveillance, and prevention measures. Yet, economic impact has emerged as an essential feature of the NTDs, which may trap people in a cycle of poverty and disease [1012]. Additional aspects not considered by the DALY metrics are the important elements of social stigma for many of the NTDs and the spillover effects to family and community members [13,14], loss of tourism [15], and health system overload (e.g., during dengue outbreaks). Ultimately NTD control and elimination efforts could produce social and economic benefits not necessarily reflected in the DALY metrics, especially among the most affected poor communities [11]. Variations in DALYs Despite the importance of the concept of disease burden and disability to the NTD community, assigning DALYs or related metrics to each NTD has been a bit of a roller-coaster ride over the past decade and may continue to be for many years to come. Significant variations in ascribing DALYs to the NTDs are due to many factors, including data scarcity and inherent difficulties in accurately estimating the number of individuals at risk, the number of incident cases, the number of prevalent cases, and, among these, the duration of the infection. Challenges also include uncertainty about the relationship between acute and chronic infections and their link to specific morbidities, duration of morbidity, and the proportion of the population infected or with morbidities Intestinal nematode infections Lymphatic filariasis Food-borne trematodiases African trypanosomiasis DALYs from GBD 2010 (numbers in parentheses indicate 95% confidence intervals) [1] * Relapsing fevers, typhus fever, spotted fever, Q fever, other rickettsioses, other mosquito-borne viral fevers, unspecified arthropod-borne viral fever, arenaviral haemorrhagic fever, toxoplasmosis, unspecified protozoal disease, taeniasis, diphyllobothriasis and sparganosis, other cestode infections, dracunculiasis, trichinellosis, strongyloidiasis, enterobiasis, and other helminthiases. doi:10.1371/journal.pntd.0002865.t001 that are treated versus untreated. An additional challenge is to obtain all of the aforementioned values stratified by age and gender, data which are seldom available for NTDs. Moreover, the affordable diagnostic tools typically used to measure NTDs in resource-constrained settings are inaccurate and many sequelae (i.e., morbidities) of NTDs are nonspecific, making it difficult to attribute them to a particular infection or risk factor. For several NTDs, controversies remain regarding what proportion of a sequelae should be ascribed to different infections or diseases. An extreme example is the case of schistosomiasis, for which disease burden estimates over the (...truncated)