Plenary Lecture

Plenary Lecture

Novel Respiratory Viruses: Epidemiology, Pathophysiology, and Optimized Strategies for Molecular Diagnosis

Dr. Oliver Schildgen
Senior Research Group Leader
Institute of Virology
University of Bonn Medical Centre
Sigmund-Freud-Str. 25
D-53105 Bonn

Viral respiratory infections occur in all age groups and all over the year. Community strategies for detection of respiratory pathogens in general and respiratory viruses in particular depend on aberrant requirements and realities. Virologists intend to detect the disease causing virus or viruses, if more than one virus contributes to the illness. The treating physician has the intention to rapidly cure the patient but often makes use of antibiotic therapy without previous confirmation of a bacterial aetiology. Both, virologists and physicians "suffer" from limited budgets, making economic strategies essential. Since 2001, several viruses have been newly discovered by improved molecular techniques, i.e. the human metapneumovirus, human bocavirus, Melaka virus, human coronaviruses NL63 and SARS, and others. Most of them are clinically indistinguishable from each other and bear the risk of severe and sometimes fatal clinical courses, at least in high risk patient groups.
Community strategies for detection of viral pathogens are consequently influenced by a number of challenges. First, regional requirements have to be taken into account. Basic care hospitals usually have fewer capacities than maximum care hospitals and frequently have to outsource virological diagnostics. Therefore, they cannot cover the whole spectrum of viruses being responsible for respiratory infections, as maximum care hospitals can or at least should do. Second, the strategy for respiratory virus detection is dependent on the cohort of patients in the respective catchment area. Maximum care hospital tend to take care for more severe cases and patients with severe comorbidities and consists of specialized departments, whereas basic care hospitals are in general confronted with any kind of medical condition that sometimes need to be transferred to specialized hospitals. Third, despite of the catchment area and the patient cohorts care is taken for, any hospital and daily practitioner is confronted with an increasing number of pathogens. This increasing number of pathogen results from systematic virus discovery studies that newly identified "old" but so far unknown viruses and from new viruses that have emerged due to zoonotic transmissions, as e.g. the SARS coronavirus.
As a consequence of those challenges, the optimal strategy for detection of respiratory pathogens should make use of a stepwise process. In the first instance it is crucial to provide the treating physician with information that can be used for therapy decisions, thus those viruses that can directly be treated with approved drugs or that have been to be treatable by an off-label use of approved drugs should be tested. This will include obligate respiratory viruses such as influenza viruses, RSV, HMPV, and contingently rhinoviruses as well as obligate respiratory pathogens like the family of herpesviruses. As an important feature of the diagnostic process, virological investigation need to be complemented by microbiological diagnostics in order to identify typical and atypical bacteria and fungi, as those pathogens can be treated with antibiotics, or, in their absence, false use of antibiotics can be avoided.
In the second instance all other frequent pathogens should be tested that have been shown to cause respiratory infections but cannot be treated specifically so far (adenoviruses, parainfluenzaviruses, coronaviruses NL63/229E/OC43/HKU1, enteroviruses, parechoviruses, hantaviruses). Finally, rare pathogens and those with unclear clinical correlation (adenoviruses, bocavirus) should be investigated. In any case, this procedure should strongly take into account a detailed anamnesis including information on travel activity and animal contacts as those events may influence the diagnostic search.

Brief Biography of the Speaker:
Priv. Doz. Dr. rer. nat. Oliver Schildgen, married, born 23.07.1974 in Nuremberg, Germany, studied biology at the University of Cologne. His diploma thesis was on the pathogensis of the picornavirus ECHO9 in newborn mice and was performed in the Institute of Virology in Cologne under the guidance of Prof. Dr. H.J. Eggers and Dr. B. Nelsen-Salz. Following his diploma thesis Oliver Schildgen worked at the University of Cologne’s Institute for Genetics and the Max-Planck-Institute for Neurological Research in Cologne and studied the Baculovirus model before performing his PhD thesis on the woodchuck hepatitis virus in the lab of Prof. Dr. M. Roggendorf at the University of Essen. Since 2002 Dr. Schildgen works at the University of Bonn and meanwhile leads a small research group that focuses on the epidemiology of new respiratory pathogens. Since December 2006 he is “Privat-Dozent” (qualified lecturer) for Virology at the Bonn University. His major research interests are new or emerging respiratory viruses and the development of hepadnaviral resistance against antiviral drugs. Since January 2007 he is coordinator of the RespViruses EU funded project (LSHM-CT-2006-037276).

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