Estimates of global, regional, and national morbidity, mortality, and aetiologies of diarrhoeal diseases: a systematic analysis for the Global Burden of Disease Study 2015

Abstract

Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) provides an up-to-date analysis of the burden of diarrhoeal diseases. This study assesses cases, deaths, and aetiologies spanning the past 25 years and informs the changing picture of diarrhoeal disease worldwide.

Methods: We estimated diarrhoeal mortality by age, sex, geography, and year using the Cause of Death Ensemble Model (CODEm), a modelling platform shared across most causes of death in the GBD 2015 study. We modelled diarrhoeal morbidity, including incidence and prevalence, using a meta-regression platform called DisMod-MR. We estimated aetiologies for diarrhoeal diseases using a counterfactual approach that incorporates the aetiology-specific risk of diarrhoeal disease and the prevalence of the aetiology in diarrhoea episodes. We used the Socio-demographic Index, a summary indicator derived from measures of income per capita, educational attainment, and fertility, to assess trends in diarrhoeal mortality. The two leading risk factors for diarrhoea-childhood malnutrition and unsafe water, sanitation, and hygiene-were used in a decomposition analysis to establish the relative contribution of changes in diarrhoea disability-adjusted life-years (DALYs).

Findings: Globally, in 2015, we estimate that diarrhoea was a leading cause of death among all ages (1·31 million deaths, 95% uncertainty interval [95% UI] 1·23 million to 1·39 million), as well as a leading cause of DALYs because of its disproportionate impact on young children (71·59 million DALYs, 66·44 million to 77·21 million). Diarrhoea was a common cause of death among children under 5 years old (499 000 deaths, 95% UI 447 000-558 000). The number of deaths due to diarrhoea decreased by an estimated 20·8% (95% UI 15·4-26·1) from 2005 to 2015. Rotavirus was the leading cause of diarrhoea deaths (199 000, 95% UI 165 000-241 000), followed by Shigella spp (164 300, 85 000-278 700) and Salmonella spp (90 300, 95% UI 34 100-183 100). Among children under 5 years old, the three aetiologies responsible for the most deaths were rotavirus, Cryptosporidium spp, and Shigella spp. Improvements in safe water and sanitation have decreased diarrhoeal DALYs by 13·4%, and reductions in childhood undernutrition have decreased diarrhoeal DALYs by 10·0% between 2005 and 2015.

Interpretation: At the global level, deaths due to diarrhoeal diseases have decreased substantially in the past 25 years, although progress has been faster in some countries than others. Diarrhoea remains a largely preventable disease and cause of death, and continued efforts to improve access to safe water, sanitation, and childhood nutrition will be important in reducing the global burden of diarrhoea.

Funding: Bill & Melinda Gates Foundation.

Figure 1

Under-5 diarrhoea mortality rate per 100 000 population (A) Under-5 mortality in 2015. (B) Under-5 mortality in 2005. ATG=Antigua and Barbuda. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. FSM=Federated States of Micronesia.

Figure 2

All ages diarrhoea mortality rate per 100 000 population (A) All-ages mortality in 2015. (B) All-ages mortality in 2005. ATG=Antigua and Barbuda. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. FSM=Federated States of Micronesia.

Figure 3

Change in diarrhoea deaths by geography, 2005–15 (A) Percentage change in under-5 deaths and (B) all-age deaths. ATG=Antigua and Barbuda. VCT=Saint Vincent and the Grenadines. LCA=Saint Lucia. TTO=Trinidad and Tobago. TLS=Timor-Leste. FSM=Federated States of Micronesia.

Figure 4

Trends in under-5 diarrhoea mortality and incidence and SDI by region, 1990–2015 The diarrhoea mortality rate per 100 000 population (A) and incidence per child-year (B) for each region is shown. Points represent 5 year increments from 1990 to 2015. The black line is a least-squares cubic spline regression using the age-standardised diarrhoea mortality rate for each geographic location and represents the expected rate based on SDI alone, where estimates above the black line are higher than expected and those below are lower than expected on the basis of SDI alone. More information on the formulation and theory of the SDI is available in the GBD 2015 cause of death capstone paper. SDI=Socio-demographic Index. GBD=Global Burden of Disease.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 5

Number of under-5 diarrhoea deaths by aetiology and geography in 2015 Each aetiology is represented by a colour across geographies, ordered left to right by geographical ranking. SDI=Socio-demographic Index. Rota=rotavirus. Crypto=Cryptosporidium spp. Shigella=Shigella spp. Adeno=adenovirus. Salm=Salmonella spp. Campy=Campylobacter spp. Cholera=Vibrio cholerae. ETEC=enterotoxigenic Escherichia coli. Ehist=Entamoeba histolytica (amoebiasis). Noro=norovirus. tEPEC=typical enteropathogenic Escherichia coli. Aero=Aeromonas spp. C diff=Clostridium difficile.

Figure 6

Risk factor and cause decomposition of changes in attributable DALYs among all ages in central Europe, eastern Europe, and central Asia, southeast Asia, east Asia, and Oceania, and South Asia, 2005–15 Changes from 2005 to 2015 are shown for (A) central Europe, eastern Europe, and central Asia, (B) southeast Asia, east Asia, and Oceania, and (C) South Asia. Black dots represent the overall rate of change in DALYs attributable to each risk or cause. Colours represent the population and cause–rate contribution to the rate of change. Bars to the left of zero show a reduction in attribution and bars to the right show an increase. Red bars show the change in risk factor or cause attribution after accounting for the other factors. DALYs=disability-adjusted life-years.

Figure 7

Risk factor and cause decomposition of changes in attributable DALYs among all ages in north Africa and the Middle East and sub-Saharan Africa, 2005–15 Changes from 2005 to 2015 are shown for (A) north Africa and the Middle East and (B) sub-Saharan Africa. Black dots represent the overall rate of change in DALYs attributable to each risk or cause. Colours represent the population and cause–rate contribution to the rate of change. Bars to the left of zero show a reduction in attribution and bars to the right show an increase. Red bars show the change in risk factor or cause attribution after accounting for the other factors. DALYs=disability-adjusted life-years.

Figure 8

Risk factor and cause decomposition of changes in attributable DALYs among all ages in Latin America and Caribbean and high-income countries, 2005–15 Changes from 2005 to 2015 are shown for (A) Latin America and Caribbean and (B) high-income countries. Black dots represent the overall rate of change in DALYs attributable to each risk or cause. Colours represent the population and cause–rate contribution to the rate of change. Bars to the left of zero show a reduction in attribution and bars to the right show an increase. Red bars show the change in risk factor or cause attribution after accounting for the other factors. DALYs=disability-adjusted life-years.