A tale of two waves: characteristics and outcomes of COVID-19 admissions during the Omicron-driven fourth wave in Cape Town, South Africa, and implications for the future

Muhammad Saadiq Moolla; Tongai Gibson Maponga; Haroon Moolla; Eve Kollenberg; Samantha Anie; Aisha Moolla; Desiree Moodley; Usha Lalla; Brian W Allwood; Neshaad Schrueder; Wolfgang Preiser; Coenraad Fn Koegelenberg; Arifa Parker

doi:10.1016/j.ijregi.2022.11.008

A tale of two waves: characteristics and outcomes of COVID-19 admissions during the Omicron-driven fourth wave in Cape Town, South Africa, and implications for the future

IJID Reg. 2023 Mar:6:42-47. doi: 10.1016/j.ijregi.2022.11.008. Epub 2022 Nov 24.

Authors

Affiliations

¹ Division of Pulmonology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
² Division of Medical Virology, University of Stellenbosch and National Health Laboratory Service, Cape Town, South Africa.
³ Centre for Infectious Disease Epidemiology and Research, School of Public Health, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
⁴ Division of General Medicine, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
⁵ SAMRC/Wits Centre for Health Economics and Decision Science - PRICELESS SA, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
⁶ National Health Laboratory Service, Tygerberg Business Unit, Cape Town, South Africa.
⁷ Division of Infectious Diseases, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.

Abstract

Objectives: The aim of this study was to describe the pattern of admissions during the fourth wave of COVID-19 in order to inform future public health policies.

Methods: This was a retrospective descriptive study of an early cohort of all adult patients with SARS-CoV-2 infection admitted to a tertiary hospital in Cape Town, South Africa, at the start of the country's fourth wave. This was compared with an early cohort from the first wave at the same institution.

Results: In total, 121 SARS-CoV-2-positive admissions from the fourth wave were included. Thirty-one (25.6%) patients had COVID-19 pneumonia, while 90 (74.4%) had incidental SARS-CoV-2 infection. (In the first wave all 116 patients had COVID-19 pneumonia.) Thirty-two (26.4%) patients self-reported complete or partial COVID-19 vaccination, of whom 12 (37.5%) were admitted with COVID-19 pneumonia. Compared with the first wave, there were fewer intensive- or high-care admissions (18/121 [14.9%] vs 42/116 [36.2%]; p < 0.001) and mortality was lower (12/121 [9.9%] vs 31/116 [26.7%]; p = 0.001).

Conclusion: Admissions to the COVID-19 wards during the fourth wave primarily included patients with incidental SARS-CoV-2 infection. There was a reduction in the need for critical care and in-hospital mortality. This changing epidemiology of COVID-19 admissions may be attributed to a combination of natural and/or vaccination-acquired immunity.

Keywords: COVID-19; Omicron variant; SARS-CoV-2; fourth wave; lockdown; pandemic restrictions.