Researchers who were searching for signs of Middle East respiratory syndrome coronavirus (MERS-CoV) in different livestock animals have found antibodies specific to the new virus in dromedary camels. This suggests that these animals have encountered MERS-CoV, or a closely related virus, and may be one reservoir of the virus that is causing MERS in humans. The results of this study, led by RIVM-researchers, were published today in The Lancet Infectious Diseases.
Reusken, et al. (2013) extracted sera from animals in the Middle East and from Spain, Netherlands and Chile. Cattle, sheep, goats, dromedary camels and other camelid species were tested for specific serum IgG by protein microarray using the receptor-binding S1 subunits of spike proteins of MERS-CoV, severe acute respiratory syndrome coronavirus, and human coronavirus OC43. Results were confirmed by virus neutralization tests for MERS-CoV and bovine coronavirus.
The researchers found that 100 percent of sera from Middle Eastern camels and 14 percent from Spanish camels had protein-specific antibodies against MERS-CoV spike. Sera from European sheep, goats, cattle, and other camelids had no such antibodies. The researchers say that MERS-CoV or a related virus has infected camel populations, and that titres and seroprevalences in sera from different locations in the Middle East suggest widespread infection.
Reference: Reusken C, et al. Middle East respiratory syndrome coronavirus neutralising serum antibodies in dromedary camels: a comparative serological study. The Lancet Infectious Diseases, Early Online Publication, Aug. 9, 2013 doi:10.1016/S1473-3099(13)70164-6