The World Health Organization (WHO) today acknowledged the four latest Middle East respiratory syndrome coronavirus (MERS-CoV) cases reported by Saudi Arabia, raising the agency's global tally to 108 cases, including 50 deaths.
Also today, Saudi Arabia's top expert on MERS-CoV said testing of some camels in his country did not reveal the virus, but he gave no details on the findings.
The WHO said MERS was confirmed in four people, whose cases were announced by Saudi Arabia in the past 2 days:
- A 55-year-old man from Medina who fell ill on Aug 17 and is hospitalized; Saudi officials said he had chronic renal failure.
- A 38-year-old man from Hafr al-Batin who had an underlying medical condition; he became ill on Aug 8 and died on Aug 17
- A 16-year-old boy and a 7-year-old girl who are family contacts of the 38-year-old and who have no symptoms
Ziad A. Memish, MD, Saudi Arabia's deputy minister for public health, discussed MERS-CoV during a webinar presented today by the Emerging Pathogens Institute at the University of Florida. He covered much of the same ground as in an Aug 21 webinar from Washington, DC, but offered a few new details.
Memish is part of a team of scientists who have hunted for the source of MERS-CoV by testing bats and other animals in Saudi Arabia. Last week the group reported that a small fragment of DNA from a bat near the home of the country's first MERS-CoV victim was a perfect match for the human virus (see today's related story).
He said the team, which includes scientists from Columbia University and the Ecohealth Alliance, also looked for the virus in camels.
"We did not find the virus in any of the camels we tested," Memish said, but he did not disclose how many camels were tested or what tests were used. He indicated that the findings would be published soon.
On Aug 8 a team of German and Dutch researchers reported finding antibodies to MERS-CoV in samples from all 50 dromedary camels from Oman that they tested, suggesting the animals had been exposed to the virus. The team also found MERS-CoV antibodies, albeit at lower levels, in 14% of a sample of dromedaries from the Canary Islands.
The findings suggested that camels may be one reservoir for the virus and a possible source of human infections.
Today Memish reiterated points he made last week about the difficulty of hunting for the virus in animals and the need for guidance from groups like the World Organization for Animal Health (OIE).
"We don't know what animals to test," he said. "If we test 1,000 bats and don't find it, is that enough? Does that mean it's not in bats? We put the question to the OIE. Until we get these answers, we deal with human issues, but with animal issues we need to go through the proper organizations."
In other comments, Memish said a genetic study of MERS-CoV isolates from the hospital-based outbreak of cases in eastern Saudi Arabia in April and May is changing investigators' view of what fueled the outbreak.
"We looked at the genetic makeup of the viruses," he said. "We think there was more than one introduction" of the virus into the hospital, not just one as previously supposed. The outbreak involved 23 confirmed cases and 11 probable cases.
Memish said a report on the findings will be published soon.
He also talked about the spotty pattern of MERS-CoV transmission, wherein only one person in a family of 20 people exposed to the virus may get infected. "We think it's probably genetic. We're doing work now to determine why the disease seems to pick out 1 or 2 people out of 20 in a household," he said.
Aug 30 WHO update
Aug 21 CIDRAP News story on bat findings and Memish's earlier webinar
Jun 19 CIDRAP News story on study of hospital outbreak