Mortality trends during the first three waves of the COVID-19 pandemic at an urban district hospital in South Africa: A retrospective comparative analysis.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is the virus responsible for the COVID-19 (C19) pandemic. South Africa (SA) experienced multiple periods of increased transmission. Tertiary, regional and central hospitals were overwhelmed, resulting in low acceptance rates.

OBJECTIVES: To compare mortality trends of patients who died in hospital from SARS-CoV-2 infection during the first three waves of infection as defined by the National Institute of Communicable Diseases of South Africa.

METHODS: This was a retrospective cohort study at a district level hospital of 311 adults who died within the first three waves of COVID-19. The study analysed case and crude fatality rates, baseline characteristics, symptomatology, clinical presentation and management of patients.

RESULTS: Waves 1, 2 and 3 yielded case fatality rates of 14.5%, 27.6% and 6.3%, respectively, and crude fatality rates of 16.7%, 33.0% and 12.2%, respectively. Black Africans were less likely to die during the third wave (odds ratio (OR) 0.54; 95% confidence interval (CI) 0.31 - 0.94). Patients in the second wave had clinical frailty scores of <5 (OR 2.51; 95% CI 1.56 - 4.03). Obesity was most prevalent in the second wave (OR 1.87; 95% CI 1.01 - 3.46), and dyslipidaemia (OR 3.03; 95% CI 1.59 - 5.77) and ischaemic heart disease (OR 3.77; 95% CI .71 - 8.33) were most prevalent during the third wave. Severe ground glass appearance was most common during the second wave (OR 2.37; 95% CI 1.49 - 3.77). Renal impairment was most prevalent during the first wave (OR 3.28; 95% CI 1.59 - 6.77), and thrombo- embolic phenomena were less common during wave three (OR 0.12; 95% CI 0.02 - 0.91).

CONCLUSION: The Beta variant was the most virulent, with the highest case and crude fatality rates in wave 2.