17 Dec 2013

Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation (The Lancet Infect Dis., abstract, edited)

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

The Lancet Infectious Diseases, Early Online Publication, 17 December 2013

doi:10.1016/S1473-3099(13)70690-X

Copyright © 2013 Elsevier Ltd All rights reserved.

Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation

Original Text

Bart L Haagmans PhD a †, Said H S Al Dhahiry PhD b †, Chantal B E M Reusken PhD c †, V Stalin Raj PhD a †, Monica Galiano PhD d, Richard Myers PhD d, Gert-Jan Godeke BSc c, Marcel Jonges MSc c, Elmoubasher Farag MPH e, Ayman Diab MPH e, Hazem Ghobashy PhD e, Farhoud Alhajri BSc e, Mohamed Al-Thani ABCM e, Salih A Al-Marri ABFM e, Hamad E Al Romaihi ABCM e, Abdullatif Al Khal PhD e, Alison Bermingham PhD d, Prof Albert D M E Osterhaus PhD a, Dr Mohd M AlHajri ABCM e, Prof Marion P G Koopmans PhD a c

 

Summary

Background

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar linked to two human cases of the infection in October, 2013.

Methods

We took nose swabs, rectal swabs, and blood samples from all camels on the Qatari farm. We tested swabs with RT-PCR, with amplification targeting the E gene (upE), nucleocapsid (N) gene, and open reading frame (ORF) 1a. PCR positive samples were tested by different MERS-CoV specific PCRs and obtained sequences were used for phylogentic analysis together with sequences from the linked human cases and other human cases. We tested serum samples from the camels for IgG immunofluorescence assay, protein microarray, and virus neutralisation assay.

Findings

We obtained samples from 14 camels on Oct 17, 2013. We detected MERS-CoV in nose swabs from three camels by three independent RT-PCRs and sequencing. The nucleotide sequence of an ORF1a fragment (940 nucleotides) and a 4·2 kb concatenated fragment were very similar to the MERS-CoV from two human cases on the same farm and a MERS-CoV isolate from Hafr-Al-Batin. Eight additional camel nose swabs were positive on one or more RT-PCRs, but could not be confirmed by sequencing. All camels had MERS-CoV spike-binding antibodies that correlated well with the presence of neutralising antibodies to MERS-CoV.

Interpretation

Our study provides virological confirmation of MERS-CoV in camels and suggests a recent outbreak affecting both human beings and camels. We cannot conclude whether the people on the farm were infected by the camels or vice versa, or if a third source was responsible.

Funding

European Union projects EMPERIE (contract number 223498), ANTIGONE (contract number 278976), and the VIRGO consortium.

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a Department of Viroscience, Erasmus Medical Center, Rotterdam, Netherlands; b Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar; c Centre for Infectious Disease Research, Diagnostics and Screening, Division of Virology, National Institute for Public Health and the Environment, Bilthoven, Netherlands; d Virus Reference Department, Public Health England, London, UK; e Supreme Council of Health, Doha, Qatar

Correspondence to: Dr Mohd M AlHajri, Supreme Council of Health, PO Box 42, Doha, Qatar

Prof Marion Koopmans, Erasmus Medical Center, Rotterdam and National Institute of Public Health and the Environment, PO Box 1, 3720BA, Bilthoven, Netherlands

† Authors contributed equally

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