High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.

While SARS-CoV-2 infection appears to have spread widely throughout Africa, documentation of associated mortality is limited. We implemented a representative serosurvey in one city of Sierra Leone in Western Africa, paired with nationally representative mortality and selected death registration data...

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Main Authors: Ahmed Osman, Ashley Aimone, Rashid Ansumana, Isaac Bogoch, Hellen Gelband, Karen Colwill, Anne-Claude Gingras, Marc-André Langlois, Ronald Carshon-Marsh, Ibrahim Bob Swaray, Amara Jambai, Mohamed Vandi, Alimatu Vandi, Mohamed Massaquoi, Anteneh Assalif, H Chaim Birnboim, Patrick E Brown, Nico Nagelkerke, Prabhat Jha
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-01-01
Series:PLOS Global Public Health
Online Access:https://doi.org/10.1371/journal.pgph.0003411
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author Ahmed Osman
Ashley Aimone
Rashid Ansumana
Isaac Bogoch
Hellen Gelband
Karen Colwill
Anne-Claude Gingras
Marc-André Langlois
Ronald Carshon-Marsh
Ibrahim Bob Swaray
Amara Jambai
Mohamed Vandi
Alimatu Vandi
Mohamed Massaquoi
Anteneh Assalif
H Chaim Birnboim
Patrick E Brown
Nico Nagelkerke
Prabhat Jha
author_facet Ahmed Osman
Ashley Aimone
Rashid Ansumana
Isaac Bogoch
Hellen Gelband
Karen Colwill
Anne-Claude Gingras
Marc-André Langlois
Ronald Carshon-Marsh
Ibrahim Bob Swaray
Amara Jambai
Mohamed Vandi
Alimatu Vandi
Mohamed Massaquoi
Anteneh Assalif
H Chaim Birnboim
Patrick E Brown
Nico Nagelkerke
Prabhat Jha
author_sort Ahmed Osman
collection DOAJ
description While SARS-CoV-2 infection appears to have spread widely throughout Africa, documentation of associated mortality is limited. We implemented a representative serosurvey in one city of Sierra Leone in Western Africa, paired with nationally representative mortality and selected death registration data. Cumulative seroincidence using high quality SARS-CoV-2 serological assays was 69% by July 2021, rising to 84% by April 2022, mostly preceding SARS-CoV-2 vaccination. About half of infections showed evidence of neutralizing antibodies. However, excess death rates were low, and were concentrated at older ages. During the peak weeks of viral activity, excess mortality rates were 22% for individuals aged 30-69 years and 70% for those over 70. Based on electronic verbal autopsy with dual independent physician assignment of causes, excess deaths during viral peaks from respiratory infections were notable. Excess deaths differed little across specific causes that, a priori, are associated with COVID, and the pattern was consistent among adults with or without chronic disease risk factors. The overall 6% excess of deaths at ages ≥30 from 2020-2022 in Sierra Leone is markedly lower than reported from South Africa, India, and Latin America. Thus, while SARS-CoV-2 infection was widespread, our study highlights as yet unidentified mechanisms of heterogeneity in susceptibility to severe disease in parts of Africa.
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spelling doaj-art-6180ff9b346b4c05b4115766ca092bea2025-08-20T02:38:55ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752024-01-0149e000341110.1371/journal.pgph.0003411High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.Ahmed OsmanAshley AimoneRashid AnsumanaIsaac BogochHellen GelbandKaren ColwillAnne-Claude GingrasMarc-André LangloisRonald Carshon-MarshIbrahim Bob SwarayAmara JambaiMohamed VandiAlimatu VandiMohamed MassaquoiAnteneh AssalifH Chaim BirnboimPatrick E BrownNico NagelkerkePrabhat JhaWhile SARS-CoV-2 infection appears to have spread widely throughout Africa, documentation of associated mortality is limited. We implemented a representative serosurvey in one city of Sierra Leone in Western Africa, paired with nationally representative mortality and selected death registration data. Cumulative seroincidence using high quality SARS-CoV-2 serological assays was 69% by July 2021, rising to 84% by April 2022, mostly preceding SARS-CoV-2 vaccination. About half of infections showed evidence of neutralizing antibodies. However, excess death rates were low, and were concentrated at older ages. During the peak weeks of viral activity, excess mortality rates were 22% for individuals aged 30-69 years and 70% for those over 70. Based on electronic verbal autopsy with dual independent physician assignment of causes, excess deaths during viral peaks from respiratory infections were notable. Excess deaths differed little across specific causes that, a priori, are associated with COVID, and the pattern was consistent among adults with or without chronic disease risk factors. The overall 6% excess of deaths at ages ≥30 from 2020-2022 in Sierra Leone is markedly lower than reported from South Africa, India, and Latin America. Thus, while SARS-CoV-2 infection was widespread, our study highlights as yet unidentified mechanisms of heterogeneity in susceptibility to severe disease in parts of Africa.https://doi.org/10.1371/journal.pgph.0003411
spellingShingle Ahmed Osman
Ashley Aimone
Rashid Ansumana
Isaac Bogoch
Hellen Gelband
Karen Colwill
Anne-Claude Gingras
Marc-André Langlois
Ronald Carshon-Marsh
Ibrahim Bob Swaray
Amara Jambai
Mohamed Vandi
Alimatu Vandi
Mohamed Massaquoi
Anteneh Assalif
H Chaim Birnboim
Patrick E Brown
Nico Nagelkerke
Prabhat Jha
High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
PLOS Global Public Health
title High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
title_full High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
title_fullStr High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
title_full_unstemmed High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
title_short High SARS-CoV-2 seroincidence but low excess COVID mortality in Sierra Leone in 2020-2022.
title_sort high sars cov 2 seroincidence but low excess covid mortality in sierra leone in 2020 2022
url https://doi.org/10.1371/journal.pgph.0003411
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