Infection and Drug Resistance (Feb 2022)

Early Evidence of Circulating SARS-CoV-2 in Unvaccinated and Vaccinated Measles Patients, September 2019–February 2020

  • Paixao J,
  • Galangue M,
  • Gaston C,
  • Carralero R,
  • Lino C,
  • Júlio G,
  • David Z,
  • Francisco M,
  • Sebastião CS,
  • Sacomboio ENM,
  • Morais J,
  • Francisco NM

Journal volume & issue
Vol. Volume 15
pp. 533 – 544

Abstract

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Joana Paixao,1,2 Maria Galangue,1 Celestina Gaston,1 Raísa Carralero,1 Celestina Lino,1 Gracieth Júlio,1 Zinga David,1 Moises Francisco,1 Cruz S Sebastião,1,3,4 Euclides NM Sacomboio,1,4 Joana Morais,1,5 Ngiambudulu M Francisco1 1Grupo de Investigação Microbiana e Imunológica, Instituto Nacional de Investigação em Saúde (National Institute for Health Research), Luanda, Angola; 2Unidade de Ensino e Investigação de Microbiologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal; 3Centro de Investigação em Saúde de Angola, Luanda, Angola; 4Instituto Superior de Ciências de Saúde, Universidade Agostinho Neto, Luanda, Angola; 5Faculdade de Medicina, Universidade Agostinho Neto, Luanda, AngolaCorrespondence: Ngiambudulu M Francisco, Grupo de Investigação Microbiana e Imunológica, Instituto Nacional de Investigação em Saúde (National Institute for Health Research), Rua: Amílcar Cabral, No. 96, por trás do Hospital Josina Machel, P.O. Box: 3635, Luanda, Angola, Tel +244 931 36 1717, Email [email protected]: The global emergence of coronavirus disease 2019 (COVID-19) has challenged healthcare and rapidly spread over the globe. Early detection of new infections is crucial in the control of emerging diseases. Evidence of early recorded COVID-19 cases outside China has been documented in various countries. In this study, we aimed to identify the time of SARS-CoV-2 infection circulation by retrospectively analyzing sera of measles patients, weeks before the reported first COVID-19 cases in Angola.Materials and Methods: We examined the humoral response against SARS-CoV-2 by using an enzyme-linked immunosorbent assay (ELISA)-based assay on a combined two-step sandwich enzyme immunoassay method. In total, we received 568 study patients with blood specimens collected from 23 September 2019 to 28 February 2020, 442 sera samples that met the criteria of the study were withdrawn and selected from the overall 568 received samples. In this study, we considered seropositives, patients who tested positive for SARS-CoV-2 immunoglobulin G (IgG) and M (IgM) antibodies with the index value > 1.Results: Of the 442 sera samples that met the criteria of the study, 204 were measles seropositive. Forty out of 204 were confirmed reactive to SARS-CoV-2 viral proteins using IgG and IgM more than 2 weeks before the first reported case in Angola. The humoral response analysis showed significant differences (p = 0.01) between the IgG and IgM indexes in the unvaccinated measles patients. Similarly, a significant difference (p = 0.001) was seen between the IgG and IgM indexes in the vaccinated measles patients.Conclusion: Here, using the humoral response analysis, we report the identification of early circulation SARS-CoV-2 infection weeks before the first recognized cases in the Republic of Angola.Keywords: infection, antibodies, pandemic, COVID-19, humoral response

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