Evidence of the simultaneous replications of active viruses in specimens positive for multiple respiratory viruses

Abstract

Genetic diagnostic assays for the detection of respiratory viruses sometimes show simultaneous multiple infections with low copy numbers. In such cases, the disease is considered caused by a single etiologic agent and others are nonspecific reactions and/or contaminations. Interferon-dependent interference is seen in dual infections of influenza and respiratory syncytial virus, which are the main causes of respiratory infections. Virus isolation is one of the solutions in detecting other active viruses present in specimens, and the air-liquid interface culture of human bronchial/tracheal epithelial cells (HBTEC-ALI) is optimal for the isolation of respiratory viruses owing to its wide range of susceptibility. In this study, we successfully confirmed the replications of various viruses from specimens with low copy numbers and passed 2-3 viruses simultaneously using HBTEC-ALI cultures, mainly including human bocavirus 1 and/or human rhinovirus.