But there’s not a lot else that can be said with certainty except that so far just two patients with the virus have come to the attention of doctors and public health authorities, who are diligently applying the lessons learned a decade ago during the SARS epidemic.
Open questions, according to the European Center for Disease Prevention and Control, include:
- Where it came from and where it is usually found – its “source” and “reservoir”;
- How it’s transmitted;
- How long it takes from infection to the appearance of symptoms;
- Whether infection can occur without symptoms.
It’s not even certain – although it’s a good assumption – that it actually caused the disease that killed a 60-year-old Saudi man and has put a 49-year-old Qatari man in intensive care in the U.K.
The first coronavirus, so-called because of the crown-like shape of the viral particles, that caught public attention was the one behind the 2002-2003 outbreak of sudden acute respiratory syndrome, or SARS. It killed nearly 800 people around the world.
The new virus may have a similar shape, but otherwise is not much like that one, according to researchers, and is so far associated with only two cases of serious disease, although many milder cases might have been missed.
But it is still “something to be concerned about,” according to James Hughes, MD, of Emory University, a former president of the Infectious Diseases Society of America.
The key to any outbreak is the ability of the pathogen to pass easily among people. If this virus had that ability, researchers would expect to see clusters of cases – family members at first and then possibly healthcare workers.
So far, there’s no evidence of that, Hughes told MedPage Today, “but, obviously, given the SARS experience, that’s the concern.”
Danish doctors, in fact, reported what looked like a cluster of cases but the disease in question turned out to be common influenza. Aside from that, nothing has turned up.
Still, there is feverish activity behind the scenes. Hughes, who is also a former head of the infectious diseases center of the CDC, said experts are looking for evidence of person-to-person transmission and any possible exposures that might link the two cases, which occurred two months apart.
One clue is that both patients had been in Saudi Arabia – the first man was a resident of the port city of Jeddah and the other had recently visited the country.
Given that the genetic sequence of the new virus puts it close to those found in bats, other scientists will be trying to find out if it originated in animals – a so-called zoonosis – and especially in bats in Saudi Arabia.
Meanwhile, Hughes said, the World Health Organization has laid out a case definition that will help doctors to pick up cases if they occur. Several groups are developing diagnostic tests and the WHO is setting up a global network of labs to use them.
And doctors have been warned to use strict infection control measures, including isolating patients and wearing gowns and masks, if there’s a suspicion of London1_novel CoV2012.
The whole elaborate process begins with an alert doctor somewhere, according to Donald Low, MD, of Mount Sinai Hospital in Toronto.
“What we rely on is good front-line docs who see a patient or patients with a febrile respiratory disease and order viral diagnostic tests to figure out what is going on,” Low told MedPage Today.
When those basic tests come back negative, he said, specimens are sent to a public health lab for more testing and perhaps some “shoe leather epidemiology” to see if other people are sick.
Eventually – assuming nothing usual turns up – the alert runs from the local and state level to national public health authorities and then to the WHO.
That’s pretty much what happened in this case, Hughes said, and it’s a sign that international health regulations put in place in 2005 – whose development was given urgency by the SARS outbreak – are working as planned.
Low noted that transmission of a virus from animals to humans is often a chance event; something like a random mutation that makes the pathogen able to infect humans or “a whacking dose of the virus (as when a) pig sneezes on you.”
The virus would then be able to cause disease in people, but would probably still need other changes to be contagious.
“Evidence that this has happened would be the recognition of transmission first in family members and than outside of a family,” Low said.
Among the lessons learned from SARS, Hughes said, is the need to be alert for that secondary transmission. “In SARS, we learned in spades that healthcare workers and family members were most at risk,” he noted.
It’s cause for optimism, both said, that no sign of that has been reported, but it’s also too early to say there’s no risk.
Source: MedPage Today