Media reports today said the Middle East respiratory syndrome coronavirus (MERS-CoV) has been detected in a camel linked to a human case in Saudi Arabia. If confirmed, the finding will mark the first time the virus has clearly been found in an animal and will strengthen the suspicion that camels are a source of human infections.
The camel was tested in the investigation of a MERS case in a 43-year-old man from Jeddah, whose illness was reported last week, according to a Canadian Press report that quoted Ziad Memish, MD, the Saudi deputy minister for public health. Testing was by polymerase chain reaction.
Memish said the man had a history of contact with sick animals that he owned and added that testing of other animals belonging to him was still under way.
The Saudi Ministry of Health (MOH) said it was working to isolate the virus and compare its genome with that of a sample from the 43-year-old man, according to an Agence France-Presse (AFP) report.
If the two isolates are identical, "this would be a first scientific discovery worldwide, and a door to identify the source of the virus," the ministry was quoted as saying.
Previous evidence in camels
Recent studies showed that camels in Oman, Egypt, and the Canary Islands carried antibodies to MERS-CoV or a closely related virus, but the virus itself had not been found in a camel or any other animal until now.
In August a team of US and Saudi scientists, including Memish, reported finding a viral fragment in bat feces in Saudi Arabia that matched up with MERS-CoV, but other scientists said the fragment was so small that it might have represented only a related virus.
Just which animals serve as the natural reservoir or hiding place of MERS-CoV, and which animals pass it to humans, have been two of the biggest mysteries about the virus. Scientists have speculated that bats, which harbor other coronaviruses, may be the reservoir and that camels may provide a pathway for the virus to reach humans.
A few previous MERS patients were reported to have had contact with camels and other farm animals. That was true in the case of a 61-year-old Qatari man reported in mid-October. Some of the animals were tested, but the virus was not detected.
Marion Koopmans, DVM, PhD, chief of virology at the National Institute of Public Health and Environment in the Netherlands, told CIDRAP News that if genetic sequence data confirm that the camel virus is MERS-CoV, it would be an important development and would point at the possible source.
"However, more work is needed to clarify how people are getting infected, as so far, apparently, very few people have animal contact, so the question remains how this virus spreads and how humans are getting infected," she said. She added that it should take only a day or two to get enough sequence data to confirm the findings.
More cases confirmed by WHO
In other MERS-CoV developments today and yesterday, the World Health Organization (WHO) confirmed three cases that were reported earlier by Saudi Arabia and Qatar, including the case in the 43-year-old Jeddah man.
The WHO said the Jeddah man became ill on Oct 27 and has been hospitalized since Nov 3. The other Saudi case involves a 72-year-old man from Riyadh who got sick Oct 23 and has been hospitalized since Oct 31. When the Saudi MOH reported the cases on Nov 7, it said both men were in intensive care units.
The case in Qatar involves a 48-year-old man with underlying medical conditions, the WHO said. He got sick on Oct 25, was hospitalized on Oct 31, and is in critical condition.
A preliminary investigation revealed that the man often visited animal barns but that he had not recently traveled and he had no contact with other MERS-CoV patients, the WHO reported.
The three cases raise the WHO's global MERS count to 151 cases, including 64 deaths.
In still other MERS news, a 68-year-old Omani man who had the first MERS case in that country died Nov 9, the Times of Oman reported today. His case was first reported on Oct 29.
An Omani health ministry official said the man had no history of recent travel but had contact with his two sons-in-law, who had participated in the Hajj to Saudi Arabia in mid-October. The patient had several chronic diseases, including diabetes and heart failure.
Tests on all the man's contacts were negative, the Times story said.
Also today, another AFP story said Saudi officials yesterday reported another death from the MERS virus, but it gave no details.
Nov 11 Canadian Press story
Nov 11 AFP story on camel infection
Nov 11 WHO statement on two Saudi cases
Nov 10 WHO statement on 48-year-old Qatari patient
Nov 11 Times of Oman story
Nov 11 AFP story on Oman death and death of Saudi patient
Sep 5 CIDRAP News story about MERS-CoV antibodies in camels
Oct 18 CIDRAP News item about 61-year-old Qatari patient