DETECTION OF HUMAN RHINOVIRUSES BY REAL TIME PCR

Background: Human rhinoviruses (hRV) cause acute upper respiratory tract infection. They also have been implicated in severe disease of the lower airway in patients with bronchial asthma, chronic obstructive pulmonary disease, cystic fibrosis, or immune deficits. The purpose of this study was to determine the prevalence of rhinoviruses in pediatric and adult patient populations and to identify the rate of dual viral infection using real time PCR.

Methods: hRV real time PCR was performed on RNA extracted from residual frozen specimens including; nasopharyngeal aspirate supernatants (NPA, N=481), bronchial alveolar lavage samples (N=20), and other respiratory specimens (N=6). Viral RNAs were extracted using a BioRobot M48 and the Virus Mini protocol (Qiagen, Gaithersburg, MD). Primers and probe sequences from the 5’-untranslated region of the hRV genome were used in a one-step RT-PCR reaction (QuantiTect Virus Kit, Qiagen). The samples had been tested for other viral pathogens by a combination of conventional methods including DFA, culture (shell vial and tube), and PCR (ProFlu+ Research Use Only Kit, Prodesse, Waukesha, WI).

Results: 69/507 samples (13.6%) were positive for hRV. 18/203 (8.9%) were from adults and 51/304 (16.8%) were from children. Only NPAs were positive for hRV. NPAs that had no other viral pathogens detected (N=287) had a hRV prevalence of 46/287 (16.0%). A similar hRV prevalence (23/194, 11.9%) was detected in NPAs containing other viral pathogens. Dual hRV/RSV infections were found in 19/140 (13.6%) specimens and dual hRV/influenza B were detected in 1/12 (8.3%) NPAs. Samples containing adenovirus, parainfluenza virus 3 or herpes simplex virus type 1 also contained hRV (N=1 for each virus).

Conclusion: In this study, the prevalence of hRV was higher in children than adults. As described in other studies, dual infection with hRV and RSV was more common than with other viral agents.