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Duration of viral shedding in patients admitted to hospital with pandemic influenza A/H1N1 2009 infection
Author(s) -
Na Shin,
Chong Yong Pil,
Kim MiNa,
Kim Won Young,
Kim Won,
Hong SangBum,
Lim ChaeMan,
Koh Younsuck,
Kwon JiWon,
Hong SooJong,
Lee SangOh,
Choi SangHo,
Kim Yang Soo,
Woo Jun Hee,
Kim SungHan
Publication year - 2011
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.21935
Subject(s) - viral shedding , oseltamivir , medicine , pandemic , interquartile range , virology , viral load , virus , influenza a virus , univariate analysis , multivariate analysis , immunology , covid-19 , disease , infectious disease (medical specialty)
Abstract Little is known about the kinetics of viral shedding of pandemic influenza A/H1N1 2009 virus. Influenza RNA, as a surrogate for viral clearance, was therefore measured on days 1, 5, 7, and 10 or more in patients admitted to hospital with pandemic influenza A/H1N1 2009 infection. A total of 72 patients who were admitted to hospital with confirmed pandemic influenza A/H1N1 2009 at a tertiary care hospital, Seoul, South Korea, between 1 September and 11 November 2009 were evaluated. The median duration of viral shedding, as assessed by RT‐PCR, was 9 days, as determined by the Kaplan–Meier method. Patients who were positive by RT‐PCR at their last assay, but who were discharged before the next RT‐PCR test due to symptom improvement, were censored from the analysis. If such patients were included, with the assumption that they had negative viral status at discharge, the median duration of viral shedding was 5 days (interquartile range, 2–8 days). These calculations thus suggest that the true median duration of viral shedding is between 5 and 9 days. Univariate analysis showed that delayed administration of antiviral therapy and comorbidity were associated with slower viral clearance. Multivariate analysis showed that oseltamivir started after the first day of symptoms (OR 2.7, 95% CI 1.2–5.7) was associated independently with slower viral clearance. These findings indicate that, in about 50% of patients admitted to hospital with pandemic influenza A/H1N1 2009, virus can be positive as tested by RT‐PCR on the eighth day after developing symptoms of influenza. The present findings also indicate that starting antiviral therapy within 24 hr of the onset of symptoms is associated with more rapid viral clearance. J. Med. Virol. 83:5–9, 2011. © 2010 Wiley‐Liss, Inc.