Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000-17: analysis for the Global Burden of Disease Study 2017

Background: Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods: We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings: The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1-65·8), 17·4% (7·7-28·4), and 59·5% (34·2-86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation: By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health. This work was primarily supported by a grant from the Bill & Melinda Gates Foundation (OPP1132415). S Aljunid reports additional funding from the International Centre for Casemix and Clinical Coding, Faculty of Medicine, National University of Malaysia and Department of Health Policy and Management, Faculty of Public Health, Kuwait University for the approval and support to participate in this research project outside of the study. A Awasthi is supported by the Department of Science and Technology, Government of India, New Delhi, through the INSPIRE Faculty Program outside of the study. A Badawi reports additional funding from the Public Health Agency of Canada outside of the study. A Barac reports additional funding from the Project of Ministry of Education, Science and Technology of the Republic of Serbia (no III45005) outside of the study. T Bärnighausen reports additional funding by the Alexander von Humboldt Foundation through the Alexander von Humboldt Professor award, funded by the German Federal Ministry of Education and Research outside of the study. F Carvalho and E Fernandez report additional funding from the Portuguese national funds (UID/MULTI/04378/2019 and UID/QUI/50006/2019) outside of the study. V M Costa reports additional funding from Fundação da Ciência e Tecnologia (FCT) for her grant (SFRH/BPD/110001/2015), which was funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, IP, under the Norma Transitória – DL57/2016/CP1334/CT0006 outside of the study. J De Neve reports additional funding from the Alexander von Humboldt Foundation outside of the study. K Deribe reports additional funding from the Wellcome Trust (grant number 201900) as part of his International Intermediate Fellowship outside of the study. D Endalew and M Moradi report additional funding from Wolkite University. M Ausloos, C Herteliu, and A Pana report additional funding from the Romanian National Authority for Scientific Research and Innovation, CNDS-UEFISCDI (project number PN-III-P4-ID-PCCF-2016-0084) outside of the study. C Herteliu reports additional funding from the European Fund for Regional Development through Operational Program for Competitiveness (Project ID P_40_382) and the European Fund for Regional Development, through InterReg Romania-Hungary (project code EMS ROHU 217) outside of the study. P Hoogar reports additional funding from the Centre for Holistic Development and Research (CHDR), Kalaghatagi and The Department of Studies in Anthropology, Karnatak University, D S Islam reports additional funding from the National Heart Foundation of Australia and the Institute for Physical Activity and Nutrition, Deakin University outside of the study. A Khatony reports additional funding from the Clinical Research Development Center of Imam Reza Hospital in Kermanshah outside of the study. J Khubchandani reports additional funding from Merck Research Laboratories outside of the study. K Krishan reports additional funding from the UGC Center of Advanced Study (CAS II) awarded to the Department of Anthropology, Panjab University, Chandigarh, India outside of the study. M Kumar reports additional funding from the Fogarty Foundation/NIH through a K43 award (TW010716-01A1) outside of the study. B Lacey reports additional funding from the National Institute for Health Research Oxford Biomedical Research Centre and the British Heart Foundation Centre of Research Excellence (Oxford, UK) outside of the study. A M Samy reports additional funding from the Egyptian Fulbright Mission Program (EFMP) outside of the study. S Seyedmousavi reports additional funding from the Intramural Program of National Institute of Health Clinical Center, Bethesda, MD, USA outside of the study. M Shey reports additional funding from the Wellcome Trust Kenji Shibuya reports additional funding from Japan's Ministry of Health, Labour and Welfare and Japan's Ministry of Education, Culture, Sport, Science and Technology outside of the study. M Sobhiyeh reports additional funding from the Clinical Research Development Center of Imam Reza Hospital, Kermanshah University of Medical Sciences outside of the study. J Soriano reports additional funding from Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain outside of the study. N Taveira reports additional funding from the LIFE study (RIA2016MC-1615) of the European and Developing Countries Clinical Trials Partnership (EDCTP) program supported by the European Union outside of the study. B Unnikrishnan reports additional funding from the Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India outside of the study. T Wijeratne reports additional funding from the Department of Medicine, Faculty of Medicine, University of Rajarata, Saliyapura, Sri Lanka outside of the study. C S Wiysonge reports additional funding from the South African Medical Research Council and the National Research Foundation of South Africa outside of the study.