High seroprevalence of anti-SARS-CoV-2 antibodies in the capital of Chad

Accepted: 13 July 2022
HTML: 3
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Background. Since the start of the COVID-19 pandemic, Chad has had 7,417 confirmed cases and 193 deaths, one of the lowest in Africa.
Objective. This study assessed SARS-CoV-2 immunity in N’Djamena.
Methods. In August-October 2021, eleven N’Djamena hospitals collected outpatient data and samples. IgG antibodies against SARSCoV- 2 nucleocapsid protein were identified using ELISA. “Bambino Gesù” Laboratory, Rome, Italy, performed external quality control with chemiluminescence assay.
Results. 25-34-year-old (35.2%) made up the largest age group at 31.9 12.6 years. 56.4% were women, 1.3 women/men. The 7th district had 22.5% and the 1st 22.3%. Housewives and students dominated. Overall seroprevalence was 69.5% (95% CI: 67.7-71.3), females 68.2% (65.8-70.5) and males 71.2% (68.6-73.8). >44-year-old had 73.9% seroprevalence. Under-15s were 57.4% positive. Housewives (70.9%), civil servants (71.5%), and health workers (9.7%) had the highest antibody positivity. N’Djamena’s 9th district had 73.1% optimism and the 3rd district had 52.5%. Seroprevalences were highest at Good Samaritan Hospital (75.4%) and National General Referral Hospital (74.7%).
Conclusion. Our findings indicate a high circulation of SARSCoV- 2 in N’Djamena, despite low mortality and morbidity after the first two COVID-19 pandemic waves. This high seroprevalence must be considered in Chad’s vaccine policy.
Azevedo MJ. The state of health system(s) in africa: challenges and opportunities. Hist Perspect State Heal Heal Syst Africa 2017;1. Available from: /pmc/articles/PMC7123888/ DOI: https://doi.org/10.1007/978-3-319-32564-4_1
Mboussou F, Ndumbi P, Ngom R, et al. Infectious disease outbreaks in the African region: overview of events reported to the World Health Organization in 2018. Epidemiol Infect 2019;147:e299. Available from: https://pubmed.ncbi.nlm.nih.gov/31709961/ DOI: https://doi.org/10.1017/S0950268819001912
Fenollar F, Mediannikov O. Emerging infectious diseases in Africa in the 21st century. New microbes new Infect 2018;26:10–8. Available from: https://pubmed.ncbi.nlm.nih.gov/30402238/ DOI: https://doi.org/10.1016/j.nmni.2018.09.004
Mennechet FJD, Dzomo GRT. Coping with COVID-19 in sub-Saharan Africa: what might the future hold? Virol Sin 2020;35:875. Available from: /pmc/articles/PMC7459943/ DOI: https://doi.org/10.1007/s12250-020-00279-2
Njenga MK, Dawa J, Nanyingi M, et al. Why is there low morbidity and mortality of COVID-19 in Africa? Am J Trop Med Hyg 2020;103:564. Available from: /pmc/articles/PMC7410455/ DOI: https://doi.org/10.4269/ajtmh.20-0474
Lawal Y. Africa’s low COVID-19 mortality rate: A paradox? Int J Infect Dis 2021 ;102:118–22. Available from: https://pubmed.ncbi.nlm.nih.gov/33075535/ DOI: https://doi.org/10.1016/j.ijid.2020.10.038
Tcheutchoua DN, Tankeu AT, Angong DLW, et al. Unexpected low burden of coronavirus disease 2019 (COVID-19) in sub-Saharan Africa region despite disastrous predictions: reasons and perspectives. Pan Afr Med J 2020;37. Available from: https://pubmed.ncbi.nlm.nih.gov/33796166/ DOI: https://doi.org/10.11604/pamj.2020.37.352.25254
Tessema SK, Nkengasong JN. Understanding COVID-19 in Africa. Nat Rev Immunol 2021 ;21:469–70. Available from: https://www.nature.com/articles/s41577-021-00579-y DOI: https://doi.org/10.1038/s41577-021-00579-y
Tchad : annuaire des statistiques sanitaires - Tome A 31ème édition année 2017 - Chad | ReliefWeb . Available from: https://reliefweb.int/report/chad/tchad-annuaire-des-statistiques-sanitaires-tome-31-me-dition-ann-e-2017
Rapport de la situation épidémiologique COVID-19 au Tchad - Chad | ReliefWeb . Available from: https://reliefweb.int/report/chad/rapport-de-la-situation-epid-miologique-covid-19-au-tchad-date-26-mars-1er-avril-23h59
Chad: WHO Coronavirus Disease (COVID-19) dashboard with vaccination data. |Available from: https://covid19.who.int/region/afro/country/td
Ghosh D, Jonathan A, Mersha TB. COVID-19 pandemic: the african paradox. J Glob Health 2020;10:1–6. Available from: /pmc/articles/PMC7506193/ DOI: https://doi.org/10.7189/jogh.10.020348
Osayomi T, Adeleke R, Enejeta L, et al. A geographical analysis of the African COVID ‑ 19 paradox : putting the poverty ‑ as ‑ a ‑ vaccine hypothesis to the test. Earth Syst Environ 2021;5:799–810. Available from: https://doi.org/10.1007/s41748-021-00234-5 DOI: https://doi.org/10.1007/s41748-021-00234-5
Chisale MRO, Ramazanu S, Mwale SE, , et al. Seroprevalence of anti‐SARS‐CoV‐2 antibodies in Africa: a systematic review and meta‐analysis. Rev Med Virol 2022;32: e2271. Available from: /pmc/articles/PMC8420234/ DOI: https://doi.org/10.1002/rmv.2271
Morton B, Barnes KG, Anscombe C, et al. In depth analysis of patients with severe SARS-CoV-2 in sub-Saharan Africa demonstrates distinct clinical and immunological profiles. medRxiv Prepr Serv Heal Sci 2021; Available from: https://pubmed.ncbi.nlm.nih.gov/33619502/ DOI: https://doi.org/10.1101/2021.02.15.21251753
Mveang Nzoghe A, Leboueny M, Kuissi Kamgaing E, et al. Circulating anti-SARS-CoV-2 nucleocapsid (N)-protein antibodies and anti-SARS-CoV-2 spike (S)-protein antibodies in an African setting: herd immunity, not there yet! BMC Res Notes 2021; 14:152. Available from: /pmc/articles/PMC8056361/ DOI: https://doi.org/10.1186/s13104-021-05570-3
Milleliri JM, Coulibaly D, Nyobe B, et al. SARS-CoV-2 infection in Ivory Coast: a serosurveillance survey among gold mine workers. Am J Trop Med Hyg 2021 ;104:1709–12. Available from: https://pubmed.ncbi.nlm.nih.gov/33735104/ DOI: https://doi.org/10.4269/ajtmh.21-0081
Batchi-Bouyou AL, Lobaloba Ingoba L, et al. High SARS-CoV-2 IgG/IGM seroprevalence in asymptomatic Congolese in Brazzaville, the Republic of Congo. Int J Infect Dis 2021;106:3–7. Available from: https://pubmed.ncbi.nlm.nih.gov/33370565/ DOI: https://doi.org/10.1016/j.ijid.2020.12.065
Brunet M, Guy F, Boisserie JR, et al. «Toumaï», miocène supérieur du Tchad, le nouveau doyen du rameau humain. Comptes Rendus - Palevol. 2004;3:275–83. DOI: https://doi.org/10.1016/j.crpv.2004.04.004
Chad. https://www.climatecentre.org/wp-content/uploads/RCCC-ICRC-Country-profiles-Chad.pdf
Nwosu K, Fokam J, Wanda F, et al. SARS-CoV-2 antibody seroprevalence and associated risk factors in an urban district in Cameroon. Nat Commun 2021;12. Available from: https://pubmed.ncbi.nlm.nih.gov/34615863/ DOI: https://doi.org/10.1038/s41467-021-25946-0
Majiya H, Aliyu-Paiko M, Balogu VT. Seroprevalence of COVID-19 in Niger State. medRxiv 2020; doi: https://doi.org/10.1101/2020.08.04.20168112. DOI: https://doi.org/10.1101/2020.08.04.20168112
Wiens KE, Mawien PN, Rumunu J, et al. Seroprevalence of Severe Acute Respiratory Syndrome Coronavirus 2 IgG in Juba. Emerg Infect Dis 2021;27:1598-1606. DOI: https://doi.org/10.3201/eid2706.210568
Ndongo FA, Guichet E, Mimbé ED, et al. Rapid increase of community SARS-CoV-2 seroprevalence during second wave of COVID-19, Yaoundé, Cameroon. Emerg Infect Dis 2022;28. Available from: https://pubmed.ncbi.nlm.nih.gov/35470795/ DOI: https://doi.org/10.3201/eid2806.212580
Kircheis R, Schuster M, Planz O. COVID-19 : mechanistic model of the African paradox supports the central role of the NF- κ B Pathway. Viruses 2021, 13:1887. DOI: https://doi.org/10.3390/v13091887
Wang Y, Huang Z, Wang L, et al. The anti-malarial artemisinin inhibits pro-inflammatory cytokines via the NF-κB canonical signaling pathway in PMA-induced THP-1 monocytes. Int J Mol Med 2011;27:233–41. Available from: http://www.spandidos-publications.com/10.3892/ijmm.2010.580/abstract DOI: https://doi.org/10.3892/ijmm.2010.580
Zhu C, Xiong Z, Chen X, et al. Artemisinin attenuates lipopolysaccharide-stimulated proinflammatory responses by inhibiting NF-κB pathway in microglia cells. PLoS One 2012;7:e35125. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0035125 DOI: https://doi.org/10.1371/journal.pone.0035125
Aldieri E, Atragene D, Bergandi L, et al. Artemisinin inhibits inducible nitric oxide synthase and nuclear factor NF-kB activation. FEBS Lett 2003;552:141–4. Available from: https://onlinelibrary.wiley.com/doi/full/10.1016/S0014-5793%2803%2900905-0 DOI: https://doi.org/10.1016/S0014-5793(03)00905-0
Kircheis R, Haasbach E, Lueftenegger D,et al. NF-κB pathway as a potential target for treatment of critical stage COVID-19 patients. Front Immunol 2020;11. Available from: https://pubmed.ncbi.nlm.nih.gov/33362782/ DOI: https://doi.org/10.3389/fimmu.2020.598444
Copyright (c) 2023 the Authors

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.