Second COVID-19 Wave Associated With Higher Incidence, Hospital Admissions, Mortality

The second wave in South Africa was larger and saw the Beta lineage dominate.

A recent study conducted by investigators from the South African National Institute for Communicable Diseases of the National Health Laboratory Service has discovered that the second wave of COVID-19 in South Africa was associated with a higher incidence of disease, a rapid increase of hospital admissions and an increase in in-hospital mortality.

Results from the study were published in the journal The Lancet Global Health.

“This 13-month study of two waves driven by two different viral lineages is both interesting and instructive,” Linda-Gail Bekker and Ntobeko A B Ntusi said in an attached commentary. “We can take several salient lessons away from this South African COVID-19 case study.”

For the study, the team of investigators analyzed data from DATCOV, a national active surveillance system for COVID-19 hospital admissions, between March 5, 2020, and March 27, 2021.

The team determined 5 wave periods, pre-wave 1, wave 1, post-wave 1, wave 2, and post-wave 2, and compared the characteristics of patients with COVID-19 admitted to hospital in both waves. Using a random-effect multivariable logistic regression, they determined risk factors for in-hospital mortality in each wave period.

Findings from the study showed that peak rates of cases, admissions and deaths occurred in the second wave. In wave 1, average growth rate in hospital admissions was 20%, compared to 43% in the second wave.

Additionally, the second wave was associated with a 31% increase in in-hospital mortality. In-hospital case-fatality risk increased from 17.7% in weeks of low admission to 26.9% in weeks of very high admission.

“Globally, we have witnessed reduced access and retention in care for patients with HIV, tuberculosis, and non-communicable diseases such as diabetes and cancer in the past 18 months,” Bekker and Ntusi said. “Strengthening of health systems to ensure continuing care for chronic conditions will be crucial to limit new variants of concern.”