Global, regional, and national burden of meningitis, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

Abstract

Background: Acute meningitis has a high case-fatality rate and survivors can have severe lifelong disability. We aimed to provide a comprehensive assessment of the levels and trends of global meningitis burden that could help to guide introduction, continuation, and ongoing development of vaccines and treatment programmes.

Methods: The Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2016 study estimated meningitis burden due to one of four types of cause: pneumococcal, meningococcal, Haemophilus influenzae type b, and a residual category of other causes. Cause-specific mortality estimates were generated via cause of death ensemble modelling of vital registration and verbal autopsy data that were subject to standardised data processing algorithms. Deaths were multiplied by the GBD standard life expectancy at age of death to estimate years of life lost, the mortality component of disability-adjusted life-years (DALYs). A systematic analysis of relevant publications and hospital and claims data was used to estimate meningitis incidence via a Bayesian meta-regression tool. Meningitis deaths and cases were split between causes with meta-regressions of aetiological proportions of mortality and incidence, respectively. Probabilities of long-term impairment by cause of meningitis were applied to survivors and used to estimate years of life lived with disability (YLDs). We assessed the relationship between burden metrics and Socio-demographic Index (SDI), a composite measure of development based on fertility, income, and education.

Findings: Global meningitis deaths decreased by 21·0% from 1990 to 2016, from 403 012 (95% uncertainty interval [UI] 319 426-458 514) to 318 400 (265 218-408 705). Incident cases globally increased from 2·50 million (95% UI 2·19-2·91) in 1990 to 2·82 million (2·46-3·31) in 2016. Meningitis mortality and incidence were closely related to SDI. The highest mortality rates and incidence rates were found in the peri-Sahelian countries that comprise the African meningitis belt, with six of the ten countries with the largest number of cases and deaths being located within this region. Haemophilus influenzae type b was the most common cause of incident meningitis in 1990, at 780 070 cases (95% UI 613 585-978 219) globally, but decreased the most (-49·1%) to become the least common cause in 2016, with 397 297 cases (291 076-533 662). Meningococcus was the leading cause of meningitis mortality in 1990 (192 833 deaths [95% UI 153 358-221 503] globally), whereas other meningitis was the leading cause for both deaths (136 423 [112 682-178 022]) and incident cases (1·25 million [1·06-1·49]) in 2016. Pneumococcus caused the largest number of YLDs (634 458 [444 787-839 749]) in 2016, owing to its more severe long-term effects on survivors. Globally in 2016, 1·48 million (1·04-1·96) YLDs were due to meningitis compared with 21·87 million (18·20-28·28) DALYs, indicating that the contribution of mortality to meningitis burden is far greater than the contribution of disabling outcomes.

Interpretation: Meningitis burden remains high and progress lags substantially behind that of other vaccine-preventable diseases. Particular attention should be given to developing vaccines with broader coverage against the causes of meningitis, making these vaccines affordable in the most affected countries, improving vaccine uptake, improving access to low-cost diagnostics and therapeutics, and improving support for disabled survivors. Substantial uncertainty remains around pathogenic causes and risk factors for meningitis. Ongoing, active cause-specific surveillance of meningitis is crucial to continue and to improve monitoring of meningitis burdens and trends throughout the world.

Funding: Bill & Melinda Gates Foundation.

Figure 1

Age-standardised incidence of meningitis per 100 000 population by location for both sexes, 2016 Age-standardised incidence rate for all causes of meningitis. ATG=Antigua and Barbuda. Isl=Islands. LCA=Saint Lucia. VCT=Saint Vincent and the Grenadines. TTO=Trinidad and Tobago. TLS=Timor-Leste. FSM=Federated States of Micornesia.

Figure 2

Cause fraction by age for deaths, incidence, and YLDs due to meningitis by cause globally and for both sexes, 2016 Cumulative cause fraction results (ie, proportion of total from all GBD causes) for deaths (A), incidence (B), and YLDs (C) for the four causes of meningitis considered by GBD: meningococcal due to Neisseria meningitidis, pneumococcal due to Streptococcus pneumoniae, Haemophilus influenza type b, and other meningitis (including other bacteria, viruses, and fungi). GBD=Global Burden of Diseases, Injuries, and Risk Factors Study. YLDs=years of life lived with disability.

Figure 3

Age-specific rate of deaths, incidence, and YLDs due to meningitis by cause globally and for both sexes, 2016 Cumulative age-specific rates for cause-specific deaths (A), incidence (B), and YLDs (C) for the four causes of meningitis considered by GBD: meningococcal due to Neisseria meningitidis, pneumococcal due to Streptococcus pneumoniae, Haemophilus influenza type b, and other meningitis (including other bacteria, viruses, and fungi). GBD=Global Burden of Disease, Injuries, and Risk Factors Study. YLDs=years of life lived with disability.

Figure 4

Age-standardised rates of deaths, incidence, and YLDs due to meningitis by cause globally and for both sexes, 1990–2016 Cumulative age-standardised rates from 1990 to 2016 for cause-specific deaths (A), incidence (B), and YLDs (C) for each of the four causes of meningitis considered by GBD: meningococcal due to Neisseria meningitidis, pneumococcal due to Streptococcus pneumoniae, Haemophilus influenza type b, and other meningitis (including other bacteria, viruses, and fungi). GBD=Global Burden of Disease, Injuries, and Risk Factors Study. YLDs=years of life lived with disability.

Figure 5

Age-standardised DALY rates for meningitis by 21 Global Burden of Disease regions by Socio-demographic Index, 1990–2016 The relationship between total disease burden due to all causes of meningitis, measured in DALYs, and sociodemographic development, as measured by the SDI. The average, or expected, rate of meningitis DALYs for a given level of SDI (black line) is calculated as the average meningitis DALY rate by age group, across all GBD estimation locations with that level of SDI. The observed values for each region for each year between 1990 and 2016 were aggregated from country results (coloured points). All points above the black line had higher meningitis DALY rates than expected based on SDI, while all those below the line had lower meningitis DALY rates than expected at that level of SDI. DALY=disability-adjusted life-years. GBD=Global Burden of Disease, Injuries, and Risk Factors Study. SDI=Socio-demographic Index.