%0 Journal Article %T Advances in Diagnosis of Respiratory Virus Infections %A Michael Loeffelholz %A Tasnee Chonmaitree %J International Journal of Microbiology %D 2010 %I Hindawi Publishing Corporation %R 10.1155/2010/126049 %X The diagnosis of respiratory virus infections has evolved substantially in recent years, with the emergence of new pathogens and the development of novel detection methods. While recent advances have improved the sensitivity and turn-around time of diagnostic tests for respiratory viruses, they have also raised important issues such as cost, and the clinical significance of detecting multiple viruses in a single specimen by molecular methods. This article reviews recent advances in specimen collection and detection methods for diagnosis of respiratory virus infections, and discusses the performance characteristics and limitations of these methods. 1. Introduction Respiratory virus infections have a major impact on health. Acute respiratory illnesses, mostly caused by viruses, are the most common illness experienced by otherwise healthy children and adults worldwide. Upper respiratory tract infections (URIs) such as common cold are exceedingly prevalent in infants and young children and continue to be common in older children and adults. Infants and young children may have 3¨C8 episodes of cold per year; those who attend daycare centers may have many more episodes per year [1¨C4]. URI can lead to complications such as acute otitis media, asthma exacerbation, and lower respiratory tract infections (LRIs). While LRIs such as pneumonia, bronchitis, and bronchiolitis occur much less frequently, they cause higher morbidity and some mortality, thus they are associated with high impact and greater healthcare costs. Approximately one third of children develop an LRI in the first year of life; LRI incidence decreases to 5%¨C10% during early school year, and 5% during preadolescent to healthy adult years [5, 6]. Common respiratory viruses include influenza A and B, respiratory syncytial virus A and B, parainfluenza virus types 1¨C3, adenovirus, rhinovirus, human metapneumovirus, and coronavirus types OC43 and 229E. Less common respiratory viruses include parainfluenza virus type 4, influenza virus C, and specific types of enteroviruses. The significance of more recently discovered viruses such as human bocavirus, coronavirus NL63, and HKU1 has yet to be elucidated [7, 8]. Clinical presentations of respiratory virus infections overlap among those caused by various viruses. In addition, clinical manifestations may mimic those of diseases caused by bacteria. Therefore, antibiotics are most often used in these infections, most of them unnecessarily. Furthermore, LRIs often require hospitalization for management such as intravenous antibiotics and symptomatic and %U http://www.hindawi.com/journals/ijmicro/2010/126049/