Bacterial meningitis: more can be done
Authors: James J Sejvar
Journal: The Lancet Neurology (2018)

Meningitis remains a substantial cause of mortality and morbidity worldwide and this is particularly true for bacterial meningitis. The big three pathogens—Haemophilus influenzae type b, Neisseria meningitidis (meningococcal), and Streptococcus pneumoniae (pneumococcal)—are responsible for a considerable share of endemic and epidemic meningitis globally. Fortunately, all three of these pathogens are vaccine-preventable. However, in The Lancet Neurology, the GBD 2016 Meningitis Collaborators1GD 2016 Meningitis CollaboratorsGlobal, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; 17: 1061-1082Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar now show both gains and shortfalls in the efforts to control these sources of meningitis, assessing epidemiological trends using data from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) study from 1990 to 2016. The GBD is a comprehensive database that provides estimates on death and disability due to hundreds of causes for 195 countries, with data broken down by age groups, sex, and Socio-demographic Index.2GBD 2015 Neurological Disorders Collaborator GroupGlobal, regional, and national burden of neurological disorders during 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015.Lancet Neurol. 2017; 16: 877-897Summary Full Text Full Text PDF PubMed Scopus (1199) Google Scholar The findings of this analysis are intriguing. The successful control of H influenzae type b meningitis through aggressive and thorough vaccination campaigns was evident in a 49·1% decrease in incidence of this type of meningitis, going from the highest among the three causes of incident meningitis in 1990 to the lowest in 2016. This decrease shows the successes of organised and targeted vaccine implementation initiatives worldwide. Similarly promising, the overall global number of deaths due to meningitis decreased by 21·0% between 1990 and 2016. However, this fact is bittersweet: during the same period, the decreases in death rates from other vaccine-preventable diseases, such as measles (a 93% decrease) and tetanus (91% decrease), dwarf the progress made in preventing deaths from meningitis.3Naghavi M Abajobir AA Abbafati C et al.Global, regional, and national age-sex specific mortality for 264 causes of death, 1980–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet. 2017; 390: 1151-1210Summary Full Text Full Text PDF PubMed Scopus (2927) Google Scholar Incidence of and deaths due to pneumococcal meningitis (the largest cause of years of life lived with disability among survivors) decreased over time, again attributable to increased widespread availability of polyvalent pneumococcal vaccines.1GD 2016 Meningitis CollaboratorsGlobal, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; 17: 1061-1082Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar Pneumococcal conjugate vaccines can result in herd immunity by preventing nasopharyngeal carriage of the bacteria targeted by the vaccine, although bacteria not covered by the vaccine are not affected, highlighting the need for continued work on even more multivalent pneumococcal vaccines. Most meningitis deaths occurred in the meningitis belt—a region roughly covering a swath of sub-Saharan Africa stretching from Senegal in the west to Ethiopia in the east. This region is marked by periodic large outbreaks of meningococcal disease, mainly meningococcus A (MenA).4Tartof S Cohn A Tarbangdo F et al.Identifying optimal vaccination strategies for serogroup A Neisseria meningitidis conjugate vaccine in the African meningitis belt.PLoS One. 2013; 8: e63605Crossref PubMed Scopus (31) Google Scholar Efforts to implement widespread vaccination for MenA, principally through the MenAfriVac programme, have led to declines; as of 2017, 21 countries in the meningitis belt had implemented vaccination in people aged 1–29 years, and the remaining few are near completion. However, only a minority of countries have implemented the MenA vaccine into their routine expanded programmes on immunisation for children.5Trotter CL Lingani C Fernandez K et al.Impact of MenAfriVac in nine countries of the African meningitis belt, 2010–15: an analysis of surveillance data.Lancet Infect Dis. 2017; 17: 867-872Summary Full Text Full Text PDF PubMed Scopus (135) Google Scholar Additionally, epidemics due to MenC, MenW, and other meningococcus serogroups continue to occur, highlighting the need for more multivalent meningococcal vaccines to control epidemics in the meningitis belt. Perhaps paradoxically, overall incident meningitis cases increased over the assessment period, going from 2·50 million in 1990 to 2·82 million in 2016.1GD 2016 Meningitis CollaboratorsGlobal, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; 17: 1061-1082Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar Similar to deaths from meningitis, incidence was highest in the meningitis belt; it was also highest in neonates. This increase in incidence appeared to be driven by the category of other meningitis causes (a term used by the GBD 2016 Meningitis Collaborators as a catch-all for other forms of bacterial, fungal, and viral meningitides). This categorisation is a limitation of the study because it fails to provide specific data for other major causes of meningitis, including group B Streptococcus, Listeria monocytogenes, nosocomial meningitides, and of course viral (aseptic) meningitis, which can still result in substantial morbidity long-term. The collaborators do provide reassurance, however, that efforts to separate out these other causes of meningitis are underway, which should increase the robustness of future data. The GBD 2016 Meningitis Collaborators astutely note barriers to the control of meningitis in resource-limited areas, including limited capacity for CSF analysis, the challenge of making a clinical diagnosis of meningitis in neonates and young children, and limitations in laboratory diagnostics that can be done on site.1GD 2016 Meningitis CollaboratorsGlobal, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; 17: 1061-1082Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar In addition to the focus on implementing aggressive vaccination campaigns, attention should be paid to addressing these other challenges. Overall, great strides in control of three of the most important causes of meningitis worldwide have been made. But as the GBD 2016 Meningitis Collaborators1GD 2016 Meningitis CollaboratorsGlobal, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet Neurol. 2018; 17: 1061-1082Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar show, substantial challenges remain to the control and prevention of bacterial meningitis, particularly in the meningitis belt. As evidenced by the data from this study, the medical community and government agencies should—and can—do better by strengthening health system infrastructure, developing more effective vaccines, wider implementation of these vaccines, and eliciting greater advocacy for implementation of these measures by stakeholders. This online publication has been corrected. The corrected version first appeared at thelancet.com/neurology on Dec 12, 2018 This online publication has been corrected. The corrected version first appeared at thelancet.com/neurology on Dec 12, 2018 I declare no competing interests. Global, regional, and national burden of meningitis, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016Meningitis 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. Full-Text PDF Open AccessCorrection to Lancet Neurol 2018; 17: 1028–30Sejvar JJ. Bacterial meningitis: more can be done. Lancet Neurol 2018; 17: 1028–30—The third and fourth sentences in the third paragraph have been changed to “Efforts to implement widespread vaccination for MenA, principally through the MenAfriVac programme, have led to declines; as of 2017, 21 countries in the meningitis belt had implemented vaccination in people aged 1–29 years, and the remaining few are near completion. However, only a minority of countries have implemented the MenA vaccine into their routine expanded programmes on immunisation for children. Full-Text PDF Open Access