Do rhinoviruses reduce the probability of viral co-detection during acute respiratory tract infections?

Background: Human rhinoviruses (HRVs) are often concurrently detected with other viruses found in the respiratory tract because of the high total number of HRV infections occurring throughout the year. This feature has previously relegated HRVs to being considered passengers in acute respiratory infections. HRVs remain poorly characterized and are seldom included as a target in diagnostic panels despite their pathogenic potential, infection-associated healthcare expenditure and relatively unmoderated elicitation of an antiviral state. Objectives: To test the hypothesis that respiratory viruses are proportionately more or less likely to co-occur, particularly the HRVs. Study design: Retrospective PCR-based analyses of 1247 specimens for 17 viruses, including HRV strains, identified 131 specimens containing two or more targets. We investigated the proportions of co-detections and compared the proportion of upper vs. lower respiratory tract presentations in the HRV positive group. Both univariate contingency table and multivariate logistic regression analyses were conducted to identify trends of association among the viruses present in co-detections. Results: Many of the co-detections occurred in patterns. In particular, HRV detection was associated with a reduced probability of detecting human adenoviruses, coronaviruses, bocavirus, metapneumovirus, respiratory syncytial virus, parainfluenza virus, influenza A virus, and the polyomaviruses KIPyV and WUPyV (p <= 0.05). No single HRV species nor cluster of particular strains predominated. Conclusions: HRVs were proportionately under-represented among viral co-detections. For some period, HRVs may render the host less likely to be infected by other viruses. (C) 2009 Elsevier B.V. All rights reserved.