[Source: The Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]


Respiratory Tract Samples, Viral Load and Genome Fraction Yield in patients with Middle East Respiratory Syndrome

Ziad A. Memish 1, Jaffar A. Al-Tawfiq 2, Hatem Q. Makhdoom 3, Abdullah Assiri 1, Raafat F. Alhakeem 1, Ali Albarrak 6, Sarah Alsubaie 7, Abdullah A. Al-Rabeeah 1, Waleed H. Hajomar 3, Raheela Hussain 3, Ali M. Kheyami 3, Abdullah Almutairi 3, Esam I. Azhar 4, Christian Drosten 5, Simon J. Watson 8, Paul Kellam 8, Matthew Cotten 8 and Alimuddin Zumla 1,9

Author Affiliations: <SUP>1</SUP>Global Centre for Mass Gatherings Medicine (GCMGM), Ministry of Health, Riyadh, Kingdom of Saudi Arabia (KSA) <SUP>2</SUP>Saudi Aramco Medical Services Organization, Saudi Aramco, Dhahran, Kingdom of Saudi Arabia and Indiana University School of Medicine, Indianapolis, IN (USA) <SUP>3</SUP>Regional Laboratory, Ministry of Health, Jeddah, Riyadh, Madinah, Dammam, KSA <SUP>4</SUP>Special Infectious Diseases Agents Unit, King Fahad Medical Research Center, King Abdualziz University, Jeddah, KSA <SUP>5</SUP>Institute of Virology, University of Bonn Medical Centre, 53127 Bonn, Germany <SUP>6</SUP>Prince Sultan Military Medical City, Riyadh, KSA <SUP>7</SUP>Pediatric Infectious Diseases, King Saud University, KSA <SUP>8</SUP>Wellcome Trust Sanger Institute, Hinxton, United Kingdom <SUP>9</SUP>Division of Infection and Immunity, University College London, and UCL Hospitals NHS Foundation Trust, London, United Kingdom

Corresponding author: Ziad A. Memish MD,FRCP(Can),FRCP(Edin),FRCP(Lond),FACP, Deputy Minister for Public Health, and Director WHO Collaborating Center for Mass Gathering Medicine Ministry of Health, and Professor, Al-Faisal University, Riyadh 11176, KSA, Email: zmemish@yahoo.com

<CITE><ABBR>J Infect Dis.</ABBR> (2014) doi: 10.1093/infdis/jiu292 </CITE>First published online: May 15, 2014


Abstract

Background.

Analysis of clinical samples of patients with new viral infections is critical to confirm the diagnosis, provide viral load and sequence data necessary for characterizing viral kinetics, transmission and evolution of the virus. We analysed samples from 112 patients infected with the recently discovered Middle East Respiratory Syndrome Coronavirus (MERS-CoV)


Methods.

Respiratory tract samples from MERS-CoV PCR-confirmed cases were analysed for yields of MERS-CoV viral load and fraction of MERS-CoV genome. These values were analyzed to determine associations with clinical sample type.


Results.

Samples from 112 MERS-CoV PCR-positive individuals were analysed: 13 Sputum samples, 64 Nasopharyngeal swabs, 30 Tracheal aspirates, 3 Broncho-alveolar lavages and 2 were of unknown origin. Tracheal aspirates yielded significantly higher MERS-CoV high viral load when compared with Nasopharyngeal swabs (p=0.005) and to Sputum (p=0.0001). Tracheal aspirates had similar viral load compared to Broncho-alveolar lavage (p=0.3079). Broncho-alveolar lavage samples and tracheal aspirates had significantly higher vital load values than nasopharyngeal swabs (p=0.0095 and p=0.0002) and Sputum samples (p=0.0009 and p=0.0001). The genome yield from tracheal aspirates and bronchoalveolar lavage samples were similar (p=0.1174).


Conclusions.

Lower respiratory tract samples yield significantly higher MERS-CoV viral load, and genome fractions than upper respiratory tract samples.


Received March 28, 2014. Revision received May 5, 2014. Accepted May 6, 2014.

The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.


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