sentence: It was not possible to identify an asymptomatic control group due to the high prevalence of upper respiratory tract symptoms such as rhinorrhoea in this population.2 Nucleic acid was extracted from a 200 μ L volume of clinical sample20 , 21 and tested for a comprehensive range of respiratory viruses using a tandem multiplex real-time PCR assay20 that detects human adenovirus ( HAdV ) species B-D ; human bocavirus ( HBoV ) ; coronaviruses ( HCoV ) OC43 , 229E , HKU1 and NL63 ; influenza viruses A , B and C ; parainfluenzaviruses ( PIV ) 1 – 4 ; KI and WU polyomaviruses ( PyV ) ; respiratory syncytial virus ( RSV ) types A and B ; and the MS2 RNA coliphage ( MS2 ) and equine herpes virus 4 ( EHV ) added to the sample lysis buffer as extraction , amplification and inhibition controls.22 , 23 Negative controls were included between every 5 clinical samples and treated as samples for the completion of the assays .