J. Med. Virol. Viral load in patients infected with pandemic H1N1 2009 influenza A virus

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<table width="100%"><tbody><tr><td>Viral load in patients infected with pandemic H1N1 2009 influenza A virus
</td></tr><tr><td>Kelvin K.W. To¹, Kwok-**** Chan¹, Iris W.S. Li¹, Tak-Yin Tsang⁴, Herman Tse¹, Jasper F.W. Chan¹, Ivan F.N. ****², Sik-To Lai⁴, Chi-Wai Leung⁵, Yat-Wah Kwan⁵, Yu-Lung Lau³, Tak-Keung Ng⁶, Vincent C.C. Cheng¹, Joseph S.M. Peiris¹, Kwok-Yung Yuen^{1 *}</td></tr><tr><td>¹Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, China
²Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, China
³Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, China
⁴Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong Special Administrative Region, China
⁵Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong Special Administrative Region, China
⁶Department of Clinical Pathology, Princess Margaret Hospital, Hong Kong Special Administrative Region, China
</td></tr><tr><td>email: Kwok-Yung Yuen (kyyuen@hkucc.hku.hk)</td></tr></tbody></table>^*Correspondence to Kwok-Yung Yuen, Carol Yu's Centre for Infection and Division of Infectious Diseases, Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Pokfulam, Hong Kong Special Administrative Region, China.
<script language="JavaScript">setDOI("ADOI=10.1002/jmv.21664")</script><table><tbody><tr><td>
</td></tr></tbody></table><table border="0" width="100%"><tbody><tr><td class="mainSectionHeader">Abstract</td></tr></tbody></table><table border="0" width="100%"><tbody><tr><td>Viral shedding profile of infections caused by the pandemic H1N1 2009 influenza A virus has not been reported. The aim of this study was to determine the viral load in different body sites. Viral loads of pandemic H1N1 virus in respiratory specimens, stool, urine, and serum were determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Respiratory specimens from patients with seasonal influenza were used as historical controls. Initial pre-treatment viral load were compared between these two groups. Serial respiratory specimens from patients with pandemic H1N1 virus infection were obtained for analysis of viral dynamics. Twenty-two pandemic H1N1 cases and 44 seasonal influenza historical controls were included. The mean initial viral load before oseltamivir therapy was 1.84 ? 10⁸ copies/ml for pandemic H1N1 virus compared with 3.28 ? 10⁸ copies/ml in seasonal influenza historical controls (P = 0.085). Among patients with pandemic H1N1 virus infection, peak viral load occurred on the day of onset of symptoms, and declined gradually afterwards, with no virus being detectable in respiratory specimens by RT-PCR 8 days and by culture 5 days after the onset of symptoms respectively, except in one patient. Pandemic H1N1 virus was detected in stool and in urine from 4/9 and 1/14 patients, respectively. Viral culture was also positive from the stool sample with the highest viral load. Younger age was associated with prolonged shedding in the respiratory tract and higher viral load in the stool. Data from this quantitative analysis of viral shedding may have implications for formulating infection control measures. J. Med. Virol. 82:1-7, 2010.
</td></tr></tbody></table><hr size="1" align="left" width="25%">Accepted: 17 August 2009<table border="0" width="100%"><tbody><tr><td class="mainSectionHeader">Digital Object Identifier (DOI)</td></tr></tbody></table>
10.1002/jmv.21664

http://www3.interscience.wiley.com/journal/123194646/abstract?CRETRY=1&SRETRY=0

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