Novel Betacoronavirus in Dromedaries of the Middle East, 2013

Patrick C.Y. Woo1

, Susanna K.P. Lau1, Ulrich Wernery, Emily Y.M. Wong, Alan K.L. Tsang, Bobby Johnson, Cyril C.Y. Yip, Candy C.Y. Lau, Saritha Sivakumar, Jian-Piao Cai, Rachel Y.Y. Fan, Kwok-Hung Chan, Ringu Mareena, and Kwok-Yung Yuen

Author affiliations: The University of Hong Kong, Hong Kong, China (P.C.Y. Woo, S.K.P. Lau, E.Y.M. Wong, A.K.L. Tsang, C.C.Y. Yip, C.C.Y. Lau, J.-P. Cai, R.Y.Y. Fan, K.H. Chan, K.-Y. Yuen); Central Veterinary Research Laboratory, Dubai, United Arab Emirates (U. Wernery, B. Johnson, S. Sivakumar, R. Mareena)

Abstract

In 2013, a novel betacoronavirus was identified in fecal samples from dromedaries in Dubai, United Arab Emirates. Antibodies against the recombinant nucleocapsid protein of the virus, which we named dromedary camel coronavirus (DcCoV) UAE-HKU23, were detected in 52% of 59 dromedary serum samples tested. In an analysis of 3 complete DcCoV UAE-HKU23 genomes, we identified the virus as a betacoronavirus in lineage A1. The DcCoV UAE-HKU23 genome has G+C contents; a general preference for G/C in the third position of codons; a cleavage site for spike protein; and a membrane protein of similar length to that of other betacoronavirus A1 members, to which DcCoV UAE-HKU23 is phylogenetically closely related. Along with this coronavirus, viruses of at least 8 other families have been found to infect camels. Because camels have a close association with humans, continuous surveillance should be conducted to understand the potential for virus emergence in camels and for virus transmission to humans.

The 2003 epidemic of severe acute respiratory syndrome (SARS) boosted interest in the discovery of new coronaviruses (CoVs) (1–3). In 2004, a novel human CoV (HCoV), named HCoV-NL63, was reported (4), and the discovery of another novel HCoV, HCoV-HKU1, was described and further characterized in 2005 (5,6) and 2006 (7). SARS-CoV–like viruses have also been reported in Chinese horseshoe bats in Hong Kong, China, and other horseshoe bats in China (8,9). The discovery in Chinese horseshoe bats in Yunnan, China, of a new SARS-CoV–like virus that uses ACE2 as receptor has furthered interest in discovering animal origins of human infections (10). We have discovered 20 other animal CoVs that include 2 novel betacoronavirus lineages and a novel genus, Deltacoronavirus (11 –20). From our studies, bats and birds were shown to be the gene sources for fueling the evolution and dissemination of alphacoronaviruses and betacoronaviruses and of gammacoronaviruses and deltacoronaviruses, respectively (18).

In 2012, a novel CoV, Middle East respiratory syndrome CoV (MERS-CoV) emerged as a cause of severe respiratory infections associated with high rates of death among humans; the virus is closely related to tylonycteris bat CoV HKU4 and pipistrellus bat CoV HKU5 (Pi-Bat CoV HKU5) (21 –23). It has also been shown that dromedaries in the Middle East possess MERS-CoV neutralizing antibodies (24). To further knowledge of the evolution and dissemination of CoVs, we conducted a molecular epidemiology study of fecal samples obtained from dromedaries in Dubai, United Arab Emirates.