Thursday, June 05, 2014

CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission

Photo: ©FAO/Ami Vitale

Credit FAO 

*** UPDATED*** 
See note at bottom


# 8708


Since August of last year, when the first evidence was presented (see Lancet: Camels Found With Antibodies To MERS-CoV-Like Virus), researchers have known that some camels on the Arabian peninsula had been exposed to – and likely carried - a MERS-like virus.


By December, researchers led by Marion Koopmans, DVM, PhD, head of virology at the Laboratory for Infectious Diseases at the RIVM in the Netherlands, determined that the human viruses and the camel viruses collected from a Qatari farm were almost an identical match (see The Lancet: Identification Of MERS Virus In Camels).


So close, in fact, that they were unable to determine whether the humans or the camels were infected first.


Since then, we’ve continued to see evidence mount supporting the notion that most camels on the Arabian peninsula – at least when they are young – get infected with the MERS coronavirus, and that they are a likely source of zoonotic spillover into humans (see mBio: MERS-CoV In Saudi Arabian Camels & EID Journal: MERS Coronavirus In A Saudi Dromedary Herd).


Acceptance of this MERS-camel connection in Saudi Arabia and the Middle East has been slow in coming. We’ve seen tepid warnings about avoiding raw camel products, along side statements from officials that there is no actual `proof’ that camels can transmit the virus to humans (see Saudi MOA Spokesman: Camel Link Unproven).


For many Saudis, the idea that camels – a beloved national symbol that literally made settlement of that arid region possible – could carry a disease deadly to humans,  is simply unthinkable. 


A concept made even harder to accept due to the widespread belief in the healthful effects of camel’s milk and urine in the treatment of disease.  While it may not convince everyone, late yesterday the NEJM published a study that finds even more evidence supporting the camel transmission scenario.


Lisa Schnirring  at CIDRAP NEWS has done a terrific job describing this research, and has comments from two top MERS researchers (Marion Koopmans, DVM, PhD & Matthew Frieman, PhD), making my job here dead simple. I would simply invite you follow the link below to read Lisa’s excellent report:


Study builds case for camel-human link in MERS

Lisa Schnirring | Staff Writer | CIDRAP News

Jun 04, 2014

In findings that shed more light on the suspected link between camels and humans, an investigation into a fatal human MERS-CoV (Middle East respiratory syndrome coronavirus) infection identified the virus in both the man and his sick camels, with genetic-sequencing showing the viruses to be identical.


The 44-year-old man, from Jeddah, Saudi Arabia, kept a herd of nine camels near the city and had had contact with the respiratory secretions of one of the animals that was sick, according to a team of scientists from King Abdulaziz University in Jeddah who reported their findings today in an early online edition of the New England Journal of Medicine.

(Continue . . .)


Here is the link to the NEJM Abstract and report:


Brief Report

Evidence for Camel-to-Human Transmission of MERS Coronavirus

Esam I. Azhar, Ph.D., Sherif A. El-Kafrawy, Ph.D., Suha A. Farraj, M.Sc., Ahmed M. Hassan, M.Sc., Muneera S. Al-Saeed, B.Sc., Anwar M. Hashem, Ph.D., and Tariq A. Madani, M.D.

June 4, 2014DOI: 10.1056/NEJMoa1401505

We describe the isolation and sequencing of Middle East respiratory syndrome coronavirus (MERS-CoV) obtained from a dromedary camel and from a patient who died of laboratory-confirmed MERS-CoV infection after close contact with camels that had rhinorrhea. Nasal swabs collected from the patient and from one of his nine camels were positive for MERS-CoV RNA. In addition, MERS-CoV was isolated from the patient and the camel. The full genome sequences of the two isolates were identical. Serologic data indicated that MERS-CoV was circulating in the camels but not in the patient before the human infection occurred. These data suggest that this fatal case of human MERS-CoV infection was transmitted through close contact with an infected camel.

(Continue . . .)



My thanks to Dr. Ian Mackay for pointing out that this transmission incident was documented previously by another team of researchers (albeit with less complete sequencing of the camel MERS-CoV genome) in the CDC’s  EID Journal  Volume 20, Number 6—June 2014.



Human Infection with MERS Coronavirus after Exposure to Infected Camels, Saudi Arabia, 2013

Ziad A. Memish, Matthew Cotten, Benjamin Meyer, Simon J. Watson, Abdullah J. Alsahafi, Abdullah A. Al Rabeeah, Victor Max Corman, Andrea Sieberg, Hatem Q. Makhdoom, Abdullah Assiri, Malaki Al Masri, Souhaib Aldabbagh, Berend-Jan Bosch, Martin Beer, Marcel A. Müller, Paul Kellam, and Christian Drosten


We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species transmission. Camels may act as a direct source of human MERS-CoV infection.

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