Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.

The SARS-CoV-2 Omicron variant has resulted in a high number of cases, but a relatively low incidence of severe disease and deaths, compared to the pre-Omicron variants. Therefore, we assessed the differences in symptom prevalence between Omicron and pre-Omicron infections in a sub-Saharan African p...

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Main Authors: Marah G Chibwana, Herbert W Thole, Cat Anscombe, Philip M Ashton, Edward Green, Kayla G Barnes, Jen Cornick, Ann Turner, Desiree Witte, Sharon Nthala, Chikondi Thom, Felistas Kanyandula, Anna Ainani, Natasha Mtike, Hope Tambala, Veronica N'goma, Dorah Mwafulirwa, Erick Asima, Ben Morton, Markus Gmeiner, Zaziwe Gundah, Gift Kawalazira, Neil French, Nicholas Feasey, Robert S Heyderman, Todd D Swarthout, Kondwani C Jambo
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2023-01-01
Series:PLOS Global Public Health
Online Access:https://journals.plos.org/globalpublichealth/article/file?id=10.1371/journal.pgph.0001575&type=printable
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author Marah G Chibwana
Herbert W Thole
Cat Anscombe
Philip M Ashton
Edward Green
Kayla G Barnes
Jen Cornick
Ann Turner
Desiree Witte
Sharon Nthala
Chikondi Thom
Felistas Kanyandula
Anna Ainani
Natasha Mtike
Hope Tambala
Veronica N'goma
Dorah Mwafulirwa
Erick Asima
Ben Morton
Markus Gmeiner
Zaziwe Gundah
Gift Kawalazira
Neil French
Nicholas Feasey
Robert S Heyderman
Todd D Swarthout
Kondwani C Jambo
author_facet Marah G Chibwana
Herbert W Thole
Cat Anscombe
Philip M Ashton
Edward Green
Kayla G Barnes
Jen Cornick
Ann Turner
Desiree Witte
Sharon Nthala
Chikondi Thom
Felistas Kanyandula
Anna Ainani
Natasha Mtike
Hope Tambala
Veronica N'goma
Dorah Mwafulirwa
Erick Asima
Ben Morton
Markus Gmeiner
Zaziwe Gundah
Gift Kawalazira
Neil French
Nicholas Feasey
Robert S Heyderman
Todd D Swarthout
Kondwani C Jambo
author_sort Marah G Chibwana
collection DOAJ
description The SARS-CoV-2 Omicron variant has resulted in a high number of cases, but a relatively low incidence of severe disease and deaths, compared to the pre-Omicron variants. Therefore, we assessed the differences in symptom prevalence between Omicron and pre-Omicron infections in a sub-Saharan African population. We collected data from outpatients presenting at two primary healthcare facilities in Blantyre, Malawi, from November 2020 to March 2022. Eligible participants were aged >1month old, with signs suggestive of COVID-19, and those not suspected of COVID-19, from whom we collected nasopharyngeal swabs for SARS-CoV-2 PCR testing, and sequenced positive samples to identify infecting-variants. In addition, we calculated the risk of presenting with a given symptom in individuals testing SARS-CoV-2 PCR positive before and during the Omicron variant-dominated period. Among 5176 participants, 6.4% were under 5, and 77% were aged 18 to 50 years. SARS-CoV-2 infection prevalence peaked in January 2021 (Beta), July 2021 (Delta), and December 2021 (Omicron). We found that cough (risk ratio (RR), 1.50; 95% confidence interval (CI), 1.00 to 2.30), fatigue (RR 2.27; 95% CI, 1.29 to 3.86) and headache (RR 1.64; 95% CI, 1.15 to 2.34) were associated with a high risk of SARS-CoV-2 infection during the pre-Omicron period. In comparison, only headache (RR 1.41; 95% CI, 1.07 to 1.86) did associate with a high risk of SARS-CoV-2 infection during the Omicron-dominated period. In conclusion, clinical symptoms associated with Omicron infection differed from prior variants and were harder to identify clinically with current symptom guidelines. Our findings encourage regular review of case definitions and testing policies to ensure case ascertainment.
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spelling doaj-art-cef0d8b38ab34873a6cb6a8fddb5730e2025-08-20T02:23:19ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752023-01-0133e000157510.1371/journal.pgph.0001575Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.Marah G ChibwanaHerbert W TholeCat AnscombePhilip M AshtonEdward GreenKayla G BarnesJen CornickAnn TurnerDesiree WitteSharon NthalaChikondi ThomFelistas KanyandulaAnna AinaniNatasha MtikeHope TambalaVeronica N'gomaDorah MwafulirwaErick AsimaBen MortonMarkus GmeinerZaziwe GundahGift KawalaziraNeil FrenchNicholas FeaseyRobert S HeydermanTodd D SwarthoutKondwani C JamboThe SARS-CoV-2 Omicron variant has resulted in a high number of cases, but a relatively low incidence of severe disease and deaths, compared to the pre-Omicron variants. Therefore, we assessed the differences in symptom prevalence between Omicron and pre-Omicron infections in a sub-Saharan African population. We collected data from outpatients presenting at two primary healthcare facilities in Blantyre, Malawi, from November 2020 to March 2022. Eligible participants were aged >1month old, with signs suggestive of COVID-19, and those not suspected of COVID-19, from whom we collected nasopharyngeal swabs for SARS-CoV-2 PCR testing, and sequenced positive samples to identify infecting-variants. In addition, we calculated the risk of presenting with a given symptom in individuals testing SARS-CoV-2 PCR positive before and during the Omicron variant-dominated period. Among 5176 participants, 6.4% were under 5, and 77% were aged 18 to 50 years. SARS-CoV-2 infection prevalence peaked in January 2021 (Beta), July 2021 (Delta), and December 2021 (Omicron). We found that cough (risk ratio (RR), 1.50; 95% confidence interval (CI), 1.00 to 2.30), fatigue (RR 2.27; 95% CI, 1.29 to 3.86) and headache (RR 1.64; 95% CI, 1.15 to 2.34) were associated with a high risk of SARS-CoV-2 infection during the pre-Omicron period. In comparison, only headache (RR 1.41; 95% CI, 1.07 to 1.86) did associate with a high risk of SARS-CoV-2 infection during the Omicron-dominated period. In conclusion, clinical symptoms associated with Omicron infection differed from prior variants and were harder to identify clinically with current symptom guidelines. Our findings encourage regular review of case definitions and testing policies to ensure case ascertainment.https://journals.plos.org/globalpublichealth/article/file?id=10.1371/journal.pgph.0001575&type=printable
spellingShingle Marah G Chibwana
Herbert W Thole
Cat Anscombe
Philip M Ashton
Edward Green
Kayla G Barnes
Jen Cornick
Ann Turner
Desiree Witte
Sharon Nthala
Chikondi Thom
Felistas Kanyandula
Anna Ainani
Natasha Mtike
Hope Tambala
Veronica N'goma
Dorah Mwafulirwa
Erick Asima
Ben Morton
Markus Gmeiner
Zaziwe Gundah
Gift Kawalazira
Neil French
Nicholas Feasey
Robert S Heyderman
Todd D Swarthout
Kondwani C Jambo
Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
PLOS Global Public Health
title Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
title_full Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
title_fullStr Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
title_full_unstemmed Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
title_short Different clinical features in Malawian outpatients presenting with COVID-19 prior to and during Omicron variant dominance: A prospective observational study.
title_sort different clinical features in malawian outpatients presenting with covid 19 prior to and during omicron variant dominance a prospective observational study
url https://journals.plos.org/globalpublichealth/article/file?id=10.1371/journal.pgph.0001575&type=printable
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