# Comparing adults with severe SARS-CoV-2 or influenza infection: South Africa, 2016–2021

## TL;DR

This study compares hospitalization characteristics of adults with severe SARS-CoV-2 or influenza infections in South Africa, highlighting differences in risk factors and outcomes.

## Contribution

The study provides novel insights into the epidemiological differences between severe SARS-CoV-2 and influenza infections in a high HIV-prevalence setting.

## Key findings

- SARS-CoV-2 patients were more likely to have diabetes and die in hospital compared to influenza patients.
- SARS-CoV-2 patients were less likely to be HIV-positive (immunosuppressed or not) or asthmatic compared to influenza patients.
- The study identifies distinct risk profiles for severe SARS-CoV-2 and influenza infections in a low-to-middle-income country.

## Abstract

Comparisons of the characteristics of individuals hospitalised with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or seasonal influenza in low-to middle-income countries with high human immunodeficiency virus (HIV) prevalence are limited.

Determine the epidemiological differences with those hospitalised with influenza or SARS-CoV-2 infection.

We investigated hospitalised individuals ≥18 years of age testing positive for seasonal influenza (2016–2019) or SARS-CoV-2 (2020–2021). We used random effects multivariable logistic regression, controlling for clustering by site, to evaluate differences among adults hospitalised with influenza or SARS-CoV-2 infection.

Compared to individuals with influenza, individuals with SARS-CoV-2 infection were more likely to be diabetic (adjusted odds ratio [aOR]: 1.70, 95% confidence interval [CI]: 1.11–2.61) or die in hospital (aOR: 2.57, 95% CI: 1.61–4.12). Additionally, those with SARS-CoV-2 infection were less likely to be living with HIV (not immunosuppressed) (aOR: 0.50, 95% CI: 0.34–0.73) or living with HIV (immunosuppressed) (aOR: 0.27, 95% CI: 0.18–0.39) compared to not living with HIV and less likely to be asthmatic (aOR: 0.21, 95% CI: 0.13–0.33) rather than those living with influenza.

Individuals hospitalised with SARS-CoV-2 had different characteristics to individuals hospitalised with influenza before the coronavirus disease 2019 (COVID-19) pandemic. Risk factors should be considered in health management especially as we move into an era of co-circulation of SARS-CoV-2 and influenza pathogens.

Identifying groups at high risk of severe disease could help to better monitor, prevent and control SARS-CoV-2 or influenza severe disease.