Multiplex PCR in Diagnosing Respiratory Tract Infections in Hospitalized Children.

OBJECTIVES: To elaborate the utility of multiplex quantitative polymerase chain reaction (multiplex qPCR) for the accurate diagnosis of severe respiratory tract infections (RTIs) in hospitalized children.

METHODS: In two separate periods during 2022, 76 respiratory specimens (combined throat/nasopharyngeal swabs) were submitted for multiplex qPCR regarding 26 respiratory pathogens. The specimens were obtained from children with severe RTIs hospitalized in the Institute for Respiratory Diseases in Children, Skopje.

RESULTS: Multiplex qPCR detected at least one respiratory pathogen in all examined specimens (76/76), with 83% (63/76) rate of co-infections. Considering that positive results are only the ones with Ct value below 28, the rates of detected pathogens and co-infections decrease to 75% and 22%, respectively. The most commonly detected pathogens during the spring period were Parainfluenza type 3 (PIV3) followed by Adenovirus (AdV) and Respiratory syncytial virus type B (RSVB) with frequency rate of 23%, 19% and 19%, respectively. During the autumn period, the most common were RSVB and Streptococcus pneumoniae with frequency rate of 31% and 17%, respectively.

CONCLUSION: Multiplex qPCR is a powerful tool for diagnosing RTIs. Semi-quantification of the viral load by reporting Ct values added higher level of evidence for accurate diagnosis. Seasonal detection of the examined viruses was notable with higher prevalence of PIV3 in spring and RSVB in autumn period.