Study: SARS-like virus in Chinese bats could jump to humans
Researchers at the University of North Carolina at Chapel Hill (UNC) say their research shows that viruses much like the SARS (severe acute respiratory syndrome) coronavirus (CoV) are still lurking in horseshoe bats in China and could jump to humans.
The scientists described their research in a Mar 13 article in the Proceedings of the National Academy of Sciences (PNAS).
Previous studies suggest that SARS-CoV originated in horseshoe bats, and recent metagenomics studies of horseshoe bat viruses identified several SARS-like DNA sequences that are at least 90% identical to the SARS virus, the report says. Further, scientists recently isolated a virus called WIV1-CoV that uses human angiotensin-converting enzyme and could replicate at low levels in human cells.
The authors said they took DNA sequences from SARS-like viruses isolated from horseshoe bats and used them to reconstruct the viruses. They then tested the viruses' ability to infect human cells and mice. The results showed that WIV1-CoV could bind to the same receptors as SARS-CoV and readily replicated in cultured human airway cells, according to a UNC press release.
"The capacity of this group of viruses to jump into humans is greater than we originally thought," Vineet Menachery, PhD, the study's first author, said in the release. "While other adaptations may be required to produce an epidemic, several viral strains circulating in bat populations have already overcome the barrier of replication in human cells and suggest reemergence as a distinct possibility."
The report says it appears that the virus would need additional adaptations, possibly involving components other than its spike protein, before it could easily spread in humans. Also, monoclonal antibodies developed to treat SARS were effective against the virus in human and animal cells, the researchers found. Existing SARS vaccines, however, would not prevent infection with it, they said.
Mar 13 PNAS report
Mar 14 UNC press release
Saudis report 2 MERS cases, 2 deaths, details on Buraydah cluster
Saudi Arabia's Ministry of Health (MOH) today reported 2 new MERS cases in Kharj and Riyadh, along with the deaths of two previously reported patients in Buraydah. The agency also released a weekly report detailing potential risk factors in the recent hospital outbreak in Buraydah.
The first new MERS-CoV (Middle East respiratory syndrome coronavirus) case-patient is a 78-year-old Saudi woman from Kharj who is hospitalized in stable condition. She had contact with camels and is not a healthcare worker, the MOH said.
The second new case involves a 45-year-old Saudi man from Riyadh. He is a healthcare worker, and the source of his exposure is under investigation, the MOH said. He had no contact with camels.
The two deaths in Buraydah involved MERS patients who were not healthcare workers,the MOH reported. The first patient was a 33-year-old foreign man with no preexisting medical conditions, and the second death involved a 60-year-old Saudi man with an underlying disease.
In addition, a 52-year-old Saudi woman from Riyadh has recovered from the disease. She is not a healthcare worker and had an underlying medical condition.
The MOH today also released its weekly MERS-CoV report, which provides details on the ongoing hospital cluster in Buraydah.
In the past three weeks (Feb 22 to Mar 12), 23 MERS-CoV cases have been reported in Saudi Arabia's Qassim region. Twelve infections were the result of secondary transmission, 5 cases are listed as primary, and 6 involve healthcare workers. Eighteen of the infections occurred in one hospital in Buraydah.
The MOH said the virus may be spreading between hospital patients and asymptomatic visitors and that case diagnosis and confirmation in Buraydah occurred later than was ideal. The agency highlights the need for greater infection control and visitor triage in hospitals, better awareness of MERS-CoV signs and symptoms among healthcare workers, and compliance with personal protective equipment guidelines during aerosol-generating procedures.