Middle East Respiratory Syndrome Coronavirus Infection in Dromedary Camels in Saudi Arabia

Abstract

The Middle East respiratory syndrome (MERS) is proposed to be a zoonotic disease; however, the reservoir and mechanism for transmission of the causative agent, the MERS coronavirus, are unknown. Dromedary camels have been implicated through reports that some victims have been exposed to camels, camels in areas where the disease has emerged have antibodies to the virus, and viral sequences have been recovered from camels in association with outbreaks of the disease among humans. Nonetheless, whether camels mediate transmission to humans is unresolved. Here we provide evidence from a geographic and temporal survey of camels in the Kingdom of Saudi Arabia that MERS coronaviruses have been circulating in camels since at least 1992, are distributed countrywide, and can be phylogenetically classified into clades that correlate with outbreaks of the disease among humans. We found no evidence of infection in domestic sheep or domestic goats.

Geographic Distribution of MERS Coronavirus among Dromedary Camels, Africa

“…In October 2013, analysis of an outbreak associated with 1 barn in Qatar (10) found dromedaries and humans to be infected with nearly identical strains of MERS-CoV. Further proof of widespread circulation of MERS-CoV among dromedaries was provided by studies from Egypt and Saudi Arabia (5,9). These findings have raised questions about the geographic distribution of MERS-CoV among camel populations elsewhere.…”

“…In August 2013, dromedary camels (Camelus dromedarius) were implicated for the first time as a possible source for human infection on the basis of the presence of MERS-CoV neutralizing antibodies in dromedaries from Oman and the Canary Islands of Spain (2). Since then, the presence of MERS-CoV antibodies in dromedaries has been reported in Jordan (3), Egypt (4,5), the United Arab Emirates (6,7), and Saudi Arabia (8,9). In October 2013, analysis of an outbreak associated with 1 barn in Qatar (10) found dromedaries and humans to be infected with nearly identical strains of MERS-CoV.…”

Middle East respiratory syndrome coronavirus (MERS-CoV) RNA and neutralising antibodies in milk collected according to local customs from dromedary camels, Qatar, April 2014

“…Evidence of infection in camels precedes the first evidence of human infection [6,7]. Recently, viral RNA has been detected in different specimens from camels and the virus has been isolated from nasal and faecal samples [6,[8][9][10][11][12].…”

Emerging infectious diseases: MERS-COV, the new Betacoronavirus pandemic

“…12 A serological study provided a conclusive evidence connecting camels (one-humped dromedaries) to MERS-CoV to which a specific antibody to this virus was found only among these creatures. Additionally, these neutralizing antibodies were found across the Middle East and Africa, 14 as they were also detected in archived camel secretion samples from Saudi Arabia and the UAE dating back to the 1990s. 15 These discoveries, indicate that MERS-CoV was previously spread among camels long before it was recognized as a human infection, and probably circulating in countries were MERS-CoV cases haven't been identified yet.…”