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A Downward Trend of the Ratio of Influenza RNA Copy Number to Infectious Viral Titer in Hospitalized Influenza A-Infected Patients

Background. Efficacy endpoints in influenza clinical trials may include clinical symptoms and virological measurements, although virology cannot serve as the primary endpoint. We investigated the relationship between influenza A RNA copy number and quantity of infectious viruses in hospitalized infl...

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Detalles Bibliográficos
Autores principales: Van Wesenbeeck, Liesbeth, D'Haese, David, Tolboom, Jeroen, Meeuws, Hanne, Dwyer, Dominic E., Holmes, Mark, Ison, Michael G., Katz, Kevin, McGeer, Allison, Sadoff, Jerald, Weverling, Gerrit Jan, Stuyver, Lieven
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4680923/
https://www.ncbi.nlm.nih.gov/pubmed/26677457
http://dx.doi.org/10.1093/ofid/ofv166
Descripción
Sumario:Background. Efficacy endpoints in influenza clinical trials may include clinical symptoms and virological measurements, although virology cannot serve as the primary endpoint. We investigated the relationship between influenza A RNA copy number and quantity of infectious viruses in hospitalized influenza patients. Methods. One hundred fifty influenza-infected, hospitalized patients were included in this prospective cohort study spanning the 2012–2013 influenza season. Daily nasopharyngeal samples were collected during hospitalization, and influenza A RNA copy number and infectious viral titer were monitored. Results. The decay rate for 50% tissue culture infectious dose (TCID(50)) was 0.51 ± 0.14 log(10) TCID(50)/mL per day, whereas the RNA copy number decreased at a rate of 0.41 ± 0.04 log(10) copies/mL per day (n = 433). The log ratio of the RNA copy number to the infectious viral titer within patient changes significantly with −0.25 ± 0.09 units per day (P = .0069). For a 12-day observation period, the decay corresponds to a decline of this ratio of 3 log influenza RNA copies. Conclusions. Influenza RNA copy number in nasal swabs is co-linear with culture, although the rate of decay of cell culture-based viral titers was faster than that observed with molecular methods. The study documented a clear decreasing log ratio of the RNA copy number to the infectious viral titer of the patients over time.