MERS Coronaviruses in Dromedary Camels, Egypt - Volume 20, Number 6—June 2014 - Emerging Infectious Disease journal - CDC
Volume 20, Number 6—June 2014
MERS Coronaviruses in Dromedary Camels, Egypt
Daniel K.W. Chu1, Leo L.M. Poon1, Mokhtar M. Gomaa, Mahmoud M. Shehata, Ranawaka A.P.M. Perera, Dina Abu Zeid, Amira S. El Rifay, Lewis Y. Siu, Yi Guan, Richard J. Webby, Mohamed A. Ali, Malik Peiris , and Ghazi Kayali
Author affiliations: The University of Hong Kong, Hong Kong, China (D.K.W. Chu, L.L.M. Poon, R.A.P.M. Perera, Y. Guan, M. Peiris);National Research Centre, Giza, Egypt (M.M. Gomaa, M.M. Shehata, D.A. Zeid, A.S. El Rifay, M.A. Ali); HKU-Pasteur Research Pole, Hong Kong (L.Y. Siu); St. Jude Children’s Research Hospital, Memphis, Tennessee, USA (R.J. Webby, G. Kayali)
Middle East respiratory syndrome (MERS) is a pneumonic illness caused by a novel lineage C betacoronavirus (CoV). During September 2012–January 20, 2014, a total of 178 confirmed cases in humans resulted in 76 deaths (1). Primary infections have originated from countries within the Arabian Peninsula, although travel-associated cases and some secondary transmission have been reported in other countries. Limited human-to-human transmission has resulted in clusters of cases, some associated with multiple rounds of human-to-human transmission (2); the remaining sporadic cases in humans are presumed to be of zoonotic origin.
MERS-CoV genomes are phylogenetically classified into 2 clades, clade A and B clusters (3). The viral genomes detected in the earliest cases in humans (clade A cluster; EMC/2012 and Jordan-N3/2012) are genetically distinct from the others (i.e., clade B). The proximate source of human infection remains unclear. MERS-CoV is related to, but not identical to, viruses detected in bats (4,5). A short RNA fragment of the conserved viral polymerase region identical to MERS-CoV has been identified in Taphozous perforates bats, but these findings need to be confirmed (6).
Serologic studies of domestic livestock in Jordan, Saudi Arabia, Qatar, United Arab Emirates, and Egypt have found high seroprevalance to a MERS-like CoV in dromedary camels but not in other domestic animals (7–11). An investigation of domestic animals in the vicinity of 2 persons with related infections detected fragments of viral RNA in dromedary camels in contact with these persons but whether this represented transmission from a unidentified source to humans and dromedaries, transmission from humans to dromedaries, or vice versa is not clear (12).
Dr Chu is a postdoctoral fellow at the Centre of Influenza Research at the University of Hong Kong. His primary research interests are virus ecology. evolution of coronaviruses, astroviruses, and zoonotic infections.
This research was supported by an internal research grant from the National Research Centre, Giza, Egypt; by a research contract from the National Institute of Allergy and Infectious Diseases contract HHSN266200700005C; and a grant from the European Community Seventh Framework Program (FP7/2007-2013) under project European management Platform for Emerging and Re-emerging Disease entities (grant agreement no. 223498) (EMPERIE).
- Figure 1. Phylogenetic analyses of a partial RNA-dependent RNA polymerase (RdRp) sequence determined from samples from dromedary camels (Camelus dromedarius) NRCE-HKU205 and NRCE-HKU270 that were positive for Middle East respiratory syndrome...
- Figure 2. Phylogenetic analyses of Middle East respiratory syndrome coronavirus (MERS-CoV) from dromedary camelsGenomic (A), spike (B), and nucleocapsid (C) sequences of the dromedary camel MERS-CoV NRCE-HKU205 (GenBank accession noKJ477102) were...
- Table 1. Results of testing nasal swab specimens from dromedary camels by RT-PCR for MERS-CoV and for other CoVs, Egypt, 2013
- Table 2. Percentage identity between ORFs of dromedary camel MERS-CoV (NRCE-HKU205) and human MERS-CoV (EMC/2012) at the nucleotide and amino acid levels
- Technical Appendix. The sequencing method and the structure of Middle East respiratory syndrome coronavirus spike protein receptor binding domain and receptor protein complex. 399 KB
Suggested citation for this article: Chu DKW, Poon LLM, Gomaa MM, Shehata MM, Perera RAPM, Zeid DA, et al. MERS coronaviruses in dromedary camels, Egypt. Emerg Infect Dis [Internet]. 2014 Jun [date cited]. http://dx.doi.org/10.3201/eid2006.140299
1These authors contributed equally to this article.