Multipathogen Detection in Patients with Respiratory Tract Infections; Identification of Non-Respiratory Viruses Using Multiplex Real Time Polymerase Reaction (PCR)

Due to the overlapping clinical characteristics of respiratory tract infections (RTI)s and unavailability of appropriate diagnostic techniques, the diagnosis of RTIs is arguing. The aim of study was to prompt diagnosis of RTI using commercial multiplex real time PCR.

The survey undertook over a period of 2 years (2019-2020), on 144 flu-negative immunocompetent outpatients. Respiratory samples were examined by multiplex PCR assays.

Study population consisted of females 77 (53.5%) and males 67 (46.5%). The mean age was 42.8 ± 23.7 SD years. Thirty-one (21.5%) of patients infected with only one viral or bacterial infections. 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), 38 (15.5%); Epstein-Barr Virus (EBV), 34 (13.8%); Mycoplasma pneumoniae, 24 (9.8%) and Human Herpes Virus 6 (HHV-6), 21 (8.5%). There were associations between pathogen finding and special age categories. Fever, cough, dyspnea and hemoptysis were associated with certain pathogens identification. There was not substantial difference between viral and bacterial Ct in relation with genders, age group and presence of comorbidities.

Multiplex diagnostic assays significantly increased the rate of appropriate diagnosis of respiratory pathogens. However, further investigation needed for finding the significance of non-respiratory viruses in respiratory specimens of immunocompetent symptomatic patients.