CSI microbiology: emerging pathogens and a staged strategy for detection and discovery.

The changing landscape of infectious diseases over the past 2 decades has astounded the medical community and the public. Emerging pathogens that cause new diseases (e.g., severe acute respiratory syndrome–associated coronavirus [SARS-CoV]), newly recognized microbial agents of known diseases (e.g., human metapneumovirus), and rapidly evolving pathogens (e.g., influenza viruses) all contribute to this seismic shift. A rate-limiting factor in our efforts to keep up with diseases caused by infectious pathogens is the absence of rapid, efficient, and affordable methods for microbial identification. Improving our strategies for diagnosing infectious etiologies will hold the key to our future relationship with infectious agents. Acute respiratory infections are, globally, the major cause of mortality in children 5 years of age. The advent of diagnostic platforms suited to surveillance as well to clinical application will reduce the morbidity and mortality of respiratory disease, both by enabling target selection for vaccine and drug development and by guiding patient care. In recent years, there has been substantial progress in applying molecular biologic advances to respiratory virus diagnosis [1]; nonetheless, a major gap has been the lack of a costeffective, systematic way to identify the causes of respiratory diseases in populations. The article by Renwick et al. [2] in this issue of the Journal makes 2 unique contributions to this field: it demonstrates the need to consider and identify rhinoviruses as a cause of serious acute respiratory disease in children, and it establishes the MassTag polymerase-chainreaction (PCR) multiplex platform as a practical tool for microbial surveillance. The MassTag PCR method, developed by Renwick et al. [2] and used in their study investigating the etiology of respiratory disease in hospitalized children, provides a paradigm for new detection strategies for early recognition and containment of a wide range of respiratory pathogens. This multiplex technology, in its first evaluation in 2005, was shown to be effective in identifying all the main respiratory viral pathogens, including respiratory syncytial virus, human parainfluenza viruses 1–3, metapneumovirus, influenza, and SARS-CoV as well as S. pneumoniae and H. influenzae [3]. In 2006, Lamson et al. [4], in the same group, went on to report the use of the method to investigate both undiagnosed influenza-like illness in New York State and the discovery of a novel genetic clade within the picornaviruses; “human rhinovirus New York” was the first new agent to be detected by use of MassTag PCR. Rhinoviruses have long been a relatively underappreciated cause of acute respiratory infection, a view that is beginning to change [5]. In their study in this issue of the Journal, performed in collaboration with the Robert Koch Institute (Berlin, Germany), Renwick et al. [2] report clear evidence that links these viruses to severe respiratory disease: 75% of viruses detected among 97 nasopharyngeal aspirates from children hospitalized with acute respiratory infection—with no pathogen identified by routine methods—were rhinoviruses. Independently, in publications following that by Lamson et al. [4], other investigators found similar evidence that associates severe respiratory disease with rhinovirus infection, implicating known serotypes of rhinovirus groups A and B as well as the same, novel viruses found in New York in pediatric lower-respiratory-tract infection [6] or asthma exacerbations [7]. With work now reported by 3 research groups employing different methods, the likely contribution of rhinoviruses to acute respiratory disease cannot be ignored and deserves further study. The diagnostic strength of highly multiplexed systems, such as the MassTag Received 12 September 2007; accepted 9 September 2007; electronically published 9 November 2007. Potential conflicts of interest: none reported. Financial support: National Institutes of Health (grant RO1 AI31971) and March of Dimes (research grant). Reprints or correspondence: Dr. Anne Moscona, Dept. of Pediatrics and of Microbiology and Immunology, Weill Medical College of Cornell University, 515 E. 71st St., Box 309, New York, NY 10021 (anm2047@med.cornell.edu). The Journal of Infectious Diseases 2007; 196:1727– 8 © 2007 by the Infectious Diseases Society of America. All rights reserved. 0022-1899/2007/19612-0003$15.00 DOI: 10.1086/524313 E D I T O R I A L C O M M E N T A R Y