Dietary staple protein quality and meningitis mortality across 54 African countries: an ecological cross-sectional study

Dietary staple protein quality and meningitis mortality across 54 African countries: an ecological cross-sectional study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Dietary staple protein quality and meningitis mortality across 54 African countries: an ecological cross-sectional study Rama Krishna Sanjeev, Raghul Gandhi Venkatesan, Dhasarathi Kumar, and 10 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9558821/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Low-income populations in sub-Saharan Africa bear a disproportionate burden of bacterial meningitis and depend predominantly on starchy staples. We hypothesised that dietary protein from staples is associated with meningitis mortality through nutritional immune compromise. Methods This ecological study included 54 African countries. Outcome was meningitis cause fraction from GBD 2023. Staple protein availability for wheat, rice, maize, millet, sorghum and cassava was obtained from FAOSTAT. Beta regression was fitted separately for each staple. The primary model included diarrhoea cause fraction, malaria cause fraction and animal protein, selected to avoid circularity from shared GBD modelling inputs. Three sensitivity specifications incorporated household air pollution, unsafe sanitation or excluded malaria. A descriptive analysis examined dietary protein and meningococcal A conjugate vaccine (MACV) coverage across 24 belt countries. Results Animal protein was independently and inversely associated with meningitis mortality across all six staple models (β=−0·024 to −0·035, p<0·001) and in two of three sensitivity specifications. Wheat protein was the only staple to reach independent significance (β=−0·024, p=0·010). Diarrhoea and malaria were consistently positive predictors. The primary model explained 70–79% of variance (Pseudo R²=0·701–0·794). Attenuation of animal protein in the household air pollution model suggested collinearity (r = −0·658), not a true absence of association. Belt countries showed 11-fold variation in meningitis mortality despite comparable MACV coverage. Conclusions Animal protein availability was independently associated with reduced meningitis mortality, supporting nutritional immune compromise as a modifying factor. Further subnational investigation is precluded by absence of staple-type disaggregation in DHS and MICS surveys. Infectious Diseases Epidemiology meningitis belt staple food protein availability food balances Meningococcus A Conjugate Vaccine ecological study Africa Full Text Additional Declarations The authors declare no competing interests. Supplementary Files SupplementaryIDoPFinal1.docx Supplementary material legends Table S1. Study variables and data sources (S1a) and circularity assessment of study covariates in relation to GBD 2023 cause of death modelling frameworks (S1b). See Additional file 1. Table S2. Correlation and multicollinearity assessment including Spearman rank correlations (S2a), key inter-variable correlations (S2b), Variance Inflation Factor results (S2c), and candidate covariate selection criteria (S2d). See Additional file 1. Table S3. Sensitivity analysis results: Sensitivity 1 — HAP model (S3a), Sensitivity 2 — Sanitation model (S3b), Sensitivity 3 — No malaria model (S3c). See Additional file 1. Table S4. Meningitis mortality, meningococcal A conjugate vaccine coverage and dietary protein availability across 24 WHO meningitis belt countries. See Additional file 1. Figure S1. Millet protein supply across African countries. See Additional file 1. Figure S2. Sorghum protein supply across African countries. See Additional file 1. Figure S3. Covariate selection flowchart for beta regression models. See Additional file 1. Figure S4a. Forest plot of animal protein beta regression coefficients across six staple models and four model specifications. See Additional file 1. Figure S4b. Forest plot of staple protein beta regression coefficients across six staple models and four model specifications. See Additional file 1. Figure S5. Animal protein availability and meningitis mortality across 24 belt countries with available MACV campaign coverage data. See Additional file 1. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9558821","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":631428209,"identity":"5f2e8c7e-1a97-4e15-b19b-06331a741129","order_by":0,"name":"Rama Krishna 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09:04:37","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":432690,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptIDoPRevisedv2.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9558821/v1_covered_e99a3970-64aa-41d8-a028-ac85bb7c1132.pdf"},{"id":108184119,"identity":"c207d273-33ea-48a2-96c8-7b4d0a710c59","added_by":"auto","created_at":"2026-04-30 09:03:17","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":3015007,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary material legends\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable S1. \u003c/strong\u003eStudy variables and data sources (S1a) and circularity assessment of study covariates in relation to GBD 2023 cause of death modelling frameworks (S1b). See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable S2. \u003c/strong\u003eCorrelation and multicollinearity assessment including Spearman rank correlations (S2a), key inter-variable correlations (S2b), Variance Inflation Factor results (S2c), and candidate covariate selection criteria (S2d). See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable S3. \u003c/strong\u003eSensitivity analysis results: Sensitivity 1 — HAP model (S3a), Sensitivity 2 — Sanitation model (S3b), Sensitivity 3 — No malaria model (S3c). See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable S4. \u003c/strong\u003eMeningitis mortality, meningococcal A conjugate vaccine coverage and dietary protein availability across 24 WHO meningitis belt countries. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S1. \u003c/strong\u003eMillet protein supply across African countries. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S2. \u003c/strong\u003eSorghum protein supply across African countries. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S3. \u003c/strong\u003eCovariate selection flowchart for beta regression models. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S4a. \u003c/strong\u003eForest plot of animal protein beta regression coefficients across six staple models and four model specifications. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S4b. \u003c/strong\u003eForest plot of staple protein beta regression coefficients across six staple models and four model specifications. See Additional file 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure S5. \u003c/strong\u003eAnimal protein availability and meningitis mortality across 24 belt countries with available MACV campaign coverage data. See Additional file 1.\u003c/p\u003e","description":"","filename":"SupplementaryIDoPFinal1.docx","url":"https://assets-eu.researchsquare.com/files/rs-9558821/v1/f2f5dc1a70f66eefa66f197c.docx"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eDietary staple protein quality and meningitis mortality across 54 African countries: an ecological cross-sectional study\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"SRM Medical College Hospital and Research Centre","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"meningitis belt, staple food protein availability, food balances, Meningococcus A Conjugate Vaccine, ecological study, Africa","lastPublishedDoi":"10.21203/rs.3.rs-9558821/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9558821/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLow-income populations in sub-Saharan Africa bear a disproportionate burden of bacterial meningitis and depend predominantly on starchy staples. We hypothesised that dietary protein from staples is associated with meningitis mortality through nutritional immune compromise.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis ecological study included 54 African countries. Outcome was meningitis cause fraction from GBD 2023. Staple protein availability for wheat, rice, maize, millet, sorghum and cassava was obtained from FAOSTAT. Beta regression was fitted separately for each staple. The primary model included diarrhoea cause fraction, malaria cause fraction and animal protein, selected to avoid circularity from shared GBD modelling inputs. Three sensitivity specifications incorporated household air pollution, unsafe sanitation or excluded malaria. A descriptive analysis examined dietary protein and meningococcal A conjugate vaccine (MACV) coverage across 24 belt countries.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnimal protein was independently and inversely associated with meningitis mortality across all six staple models (β=−0·024 to −0·035, p\u0026lt;0·001) and in two of three sensitivity specifications. Wheat protein was the only staple to reach independent significance (β=−0·024, p=0·010). Diarrhoea and malaria were consistently positive predictors. The primary model explained 70–79% of variance (Pseudo R²=0·701–0·794). Attenuation of animal protein in the household air pollution model suggested collinearity (r = −0·658), not a true absence of association. Belt countries showed 11-fold variation in meningitis mortality despite comparable MACV coverage.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnimal protein availability was independently associated with reduced meningitis mortality, supporting nutritional immune compromise as a modifying factor. Further subnational investigation is precluded by absence of staple-type disaggregation in DHS and MICS surveys.\u003c/p\u003e","manuscriptTitle":"Dietary staple protein quality and meningitis mortality across 54 African countries: an ecological cross-sectional study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-30 09:00:21","doi":"10.21203/rs.3.rs-9558821/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6a76652d-2f06-4d61-85c9-fc5214185514","owner":[],"postedDate":"April 30th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":67199845,"name":"Infectious Diseases"},{"id":67199846,"name":"Epidemiology"}],"tags":[],"updatedAt":"2026-05-03T01:10:36+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-30 09:00:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9558821","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9558821","identity":"rs-9558821","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}