# Distinct characteristics on mixed infection of SARS-CoV-2 variants and other respiratory pathogens among patients with acute COVID-19 in central China

## TL;DR

This study examines mixed infections of SARS-CoV-2 variants and other respiratory pathogens in acute COVID-19 patients in central China, highlighting clinical risk factors and underestimation of such infections.

## Contribution

The study identifies risk factors and clinical patterns of mixed SARS-CoV-2 variant infections and co-pathogens in China, emphasizing the need for active surveillance.

## Key findings

- 54.6% of patients had co-existing respiratory pathogen infections, with Mycoplasma pneumoniae being the most common.
- Mixed infections were linked to longer hospital stays, ICU admission, and delayed virus detection.
- Early biomarkers like white blood cell count and D-dimer can predict mixed infections and treatment outcomes.

## Abstract

Reports on mixed infection with different severe acute respiratory syndrome coronavirus 2 variants and other respiratory pathogens in patients with acute coronavirus disease in China remain scarce. In this study, we analyzed the clinical characteristics of mixed infections involving different severe acute respiratory syndrome coronavirus 2 variants and other respiratory pathogens in patients with acute coronavirus disease in central China.

Nested polymerase chain reactions and metagenomic next-generation sequencing were employed to identify severe acute respiratory syndrome coronavirus 2 variants. Clinical data, including hospitalization days, severity classification, outcomes, and laboratory data, were collected and analyzed.

Seven patients had mixed infections with different severe acute respiratory syndrome coronavirus 2 variants in samples collected on different dates. Overall, 54.6% (83/152) of patients had co-existing respiratory pathogen infection. The most common co-existing respiratory pathogen was Mycoplasma pneumoniae. Longer hospital stays, intensive care unit admission, and prolonged duration from admission to positive severe acute respiratory syndrome coronavirus 2 sample detection were independent risk factors for acute coronavirus disease infection with different respiratory pathogens. Severity classification, mixed infection, cerebral fraction, and fever were independent risk factors for failed treatment. Early detection of white blood cell count, procalcitonin, and D-dimer concentrations can help predict mixed respiratory infections and treatment outcomes.

The phenomenon of mixed infection with different variants in patients with coronavirus disease may have been underestimated. Therefore, active surveillance of severe acute respiratory syndrome coronavirus 2 variants should be performed in older patients with comorbidities.