Two probable cases of human-to-human transmission of the new coronavirus that’s killed six people increase the pathogen’s threat to the European Union, according to the bloc’s disease-tracking agency.
The appearance of a mild case of the disease caused by the virus also raises concern because it suggests more people may be infected than are known, have few or no symptoms, and are spreading the bug to others, the European Centre for Disease Prevention and Control said in a report late yesterday.
The new virus, which is related to the one that killed 774 people in the SARS outbreak of 2002 and 2003, is known to have infected 12 people in the past year, and half of them died. Ten of those infected either lived in or traveled to the Middle East, while two people diagnosed in the U.K. last week almost certainly contracted the bug from a family member who had traveled to Saudi Arabia and Pakistan, the ECDC said.
“The fact that an infection has come to Europe on a commercial flight and then resulted in two probable human-to-human transmission episodes has increased the threat,” the ECDC said in the report. “There is a lot more that we do not know than we know about this virus.”
The coronavirus can infect the lining of a person’s airways faster than the SARS bug, according to a study published yesterday, though researchers still don’t know how easy it is to transmit from person to person.
There’s no evidence so far of “SARS-like super-spreading events to date,” the ECDC said. Like H5N1 bird flu, the virus may have the potential to spread more widely, but not without acquiring multiple genetic changes, said Ian Jones, a professor of virology at the University of Reading in England.
“The most likely outcome for the current infections is a dead end, that is, the virus will become extinct locally,” Jones said in e-mailed comments distributed by the U.K.’s Science Media Centre.
Of the three recent cases in the the U.K., the first patient, a man, is still receiving treatment, while a male relative who had an underlying condition that may have made him susceptible to respiratory infections has died. A younger female relative, who was exposed to the original case while he was hospitalized, had mild flu-like symptoms and has recovered, the ECDC said. She is one of only two women infected so far, the agency said.
While the virus is related to the one responsible for SARS, it shouldn’t be described as SARS-like because the two pathogens are genetically distinct, the World Health Organization has said. Genetic evidence suggests the virus is most closely related to a coronavirus found in bats, the Geneva-based WHO said in November.
The earliest known cases are two hospital workers aged 25 and 45 in Jordan who died in April but weren’t found to have the coronavirus until samples were tested in November. A further nine less severe cases associated with the same hospital fit the WHO definition for the illness and haven’t yet been tested, the ECDC said in its report.