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Background: Laboratories often have difficulties obtaining positive control material for polymerase chain reaction (PCR) diagnosis of rare or emerging viruses. This is particularly problematic during outbreaks caused by emerging infectious diseases, when delays can impede the public health response., Objectives: The aim of this study was to develop a simple approach for preparing real-time PCR positive reaction controls for rare or emerging viruses., Study Design: We describe a universal method for preparing PCR positive reaction controls (Uni-Control), which uses two synthetic control oligonucleotides and irrelevant viral nucleic acid as an initiator template. In this study, we prepared Uni-Controls for novel influenza A(H1N1) and human metapneumovirus (HMPV) RT-PCR assays. Parainfluenza type 2 virus RNA and equine herpes virus DNA were used as initiator templates., Results: Using the Uni-Controls, characteristic sigmoidal real-time PCR amplification curves were observed in the influenza A(H1N1) and HMPV RT-PCR assays. Comparable cycle threshold values were observed in both assays when using the same concentration of the initiator template., Conclusions: The Uni-Control method for preparing real-time PCR positive reaction controls provides an interim measure by which real-time PCR assays can be rapidly introduced for rare or emerging viruses in the absence of wild-type control material. The system is versatile and we propose can readily be adapted to almost any viral template., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

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 < or = 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.