Multipathogen detection in patients with respiratory tract infection: identification of non-respiratory viruses using multiplex real-time polymerase reaction

Background: Due to the overlapping clinical characteristics of respiratory tract infections (RTIs) and the unavailability of appropriate diagnostic techniques, the diagnosis of RTIs is controversial.

Objectives: The study aimed to prompt the diagnosis of RTIs using commercial multiplex real-time PCR.

Methods: The survey undertook for two years (2019-2020) on 144 flu-negative immunocompetent outpatients. Respiratory samples were examined by multiplex PCR assays.

Results: Study population consisted of females (n = 77, 53.5%) and males (n = 67, 46.5%). The mean age was 42.8±23.7 years. Thirty-one (21.5%) patients were infected with only one viral or bacterial infection. Eighty-two (57%) were infected with more than one pathogen. Ninety-five (37%) and 161 (62%) tests were positive for bacterial and viral pathogens, respectively. Community-acquired Pneumonia (CAP) and atypical CAP pathogens included 17% and 10% of respiratory specimens, respectively. The predominant pathogens consisted of Human Herpes Virus 7 (HHV-7) (n = 38, 15.5%), Epstein-Barr Virus (EBV) (n = 34, 13.8%), Mycoplasma pneumoniae (n = 24, 9.8%), and Human Herpes Virus 6 (HHV-6) (n = 21, 8.5%). There were associations between pathogen findings and special age categories. Fever, cough, dyspnea, and hemoptysis were associated with certain pathogens. There was no substantial difference between viral and bacterial Ct concerning gender, age group, and comorbidities.

Conclusions: Multiplex diagnostic assays significantly increased the rate of appropriate diagnosis of respiratory pathogens. How-ever, further investigation is needed to find non-respiratory viruses’ significance in respiratory specimens of immunocompetent symptomatic patients.