Use of multiplex molecular respiratory panel in COVID-19 patients with suspected co-infections: Insights and considerations in results interpretation

As critically ill COVID-19 patients are prone to infections by other respiratory pathogens, this study aimed to investigate the detection of respiratory co-pathogens in such patients, by employing a multiplex respiratory molecular panel. Conducted at Universiti Sains Malaysia Specialist Hospital (HPUSM) from November 1, 2021, to November 1, 2022, this retrospective cross-sectional study analysed adults admitted with confirmed COVID-19. Oropharyngeal/ nasopharyngeal swabs collected upon admission were tested using the Fast Track Diagnostic (FTD®) Respiratory Pathogens 33 multiplex kit to detect other respiratory pathogens. Within 48 hours of admission, the presence and type of organisms were determined to assess community co-infections. Among 48 critically ill COVID-19 patients (26 male; mean age, 62.2 years), clinically significant organisms were found in 32 patients (67%). Bacterial co-infections or co-colonization were detected in 91% (29/32) of these patients, with Klebsiella pneumoniae (40%) and Staphylococcus aureus (23%) were the most common, followed by Streptococcus pneumoniae (11%), Moraxella catarrhalis (4%), and Haemophilus influenzae (2%). Fungal (6%) and viral (2%) co-infections were less frequent. The use of syndromic respiratory panel in critically ill COVID-19 patients offers the advantage of being highly sensitive, rapid, and able to detect multiple pathogens. However, detection of multiple respiratory pathogens needs to be interpreted with caution, taking into consideration patient's clinical and radiological findings, as well as quantitative molecular data.