Virological study changes our assessment of the new coronavirus
A new virological study changes our assessment of the new coronavirus. The research group of Professor Christian Drosten (Bonn University/DZIF) has shown that the new coronavirus does not use the same receptor to enter the cell as the SARS coronavirus uses. Also, the new coronavirus seems able to penetrate not only into human cells, but also into various other animal cells, such as bats or pigs.
Bonn – Since the beginning of the outbreak and the discovery of the new coronavirus, virologists have stressed that, while the two coronaviruses do come from the same family, they are different. They now have clear evidence of these differences. This distinction may seem like a purely academic discussion, but it has enormous importance for the risk assessment and measures to be taken by the public health service. It also changes the way we think about the outbreak event.
Previous experience shows that coronaviruses always have a typical host, and do not swap back and forth between man and animal. Since this new coronavirus behaves so "promiscuously", in that it infects human and animal cells, it could be difficult to record this virus epidemiologically and effectively stem its transmission to humans. It also demands a refocus in surveillance: We must now record diseases in both the human and the animal population.
Every virus requires a cellular receptor to penetrate into a cell. Where this receptor is located in the tissue influences the course of infection. If the virus is located in the deep lung tissues, as with the SARS coronavirus, the infectious particles can only cause an infection if find their way into the lower respiratory tract. However, since the new coronavirus penetrates via a different, as yet unknown receptor in the human cell, the measures taken to combat and treat SARS may not prove as effective this time. What needs to be done over the next few weeks is to find the actual receptor and its location so that effective measures for protecting against infection and therapeutic treatment options can be developed.
The little knowledge we have about how the new coronavirus spreads gives us no indication as to how dangerous it is. The WHO has reported nine patients so far, five of which have died. This equates to a death rate of more than 50 percent. Since it is still unclear whether we know of all patients or only those with severe symptoms, it is difficult to make a prediction. It is possible, and indeed probable in this early breakout phase, that a dark figure of people who are not so severely ill has not been recorded.
The cases so far confirmed at the laboratory were of severely ill people. Coherent patient groups have also been recorded in which human-to-human transmission can be assumed. The international health authorities are therefore following new cases with great attention, and have modified the case definition. The WHO is now appealing to doctors to test patients for the new coronavirus even if they have no clear travel history, and to report these cases to the public health department.
The Emerging Infections unit of the German Centre for Infection Research (DZIF) is researching intensively into emergent and re-emergent viruses. The remodelling of the pathogen detection method for the new coronavirus, under substantial input from DZIF member Professor Christian Drosten, is another research achievement from this group that opens up a new school of thought for the international community. With it, DZIF and in particular the research group of Christian Drosten underscores its importance for combatting newly emerging viruses. The German Centre for Infection Research (DZIF) is a newly established affiliation of the leading research institutes for the life sciences in Germany. The German Federal Ministry of Education and Research (BMBF) has funded the centre since November 2011.
Quotes
Professor Christian Drosten (Universität Bonn): “Unfortunately, even after three months of intensive research, there are more questions than answers regarding the new virus. Our newly published data provide at least a new school of thought as to why the epidemiological picture is so atypical for a coronavirus. Yet, it is too early for a change in strategy – now, more than ever, we must demand for intensified monitoring and include breeding animals in the virus’s region of origin. Sadly, there is little progress at this point and little real willingness to cooperate.”
Professor Stephan Becker (Philipps-Universität Marburg): “The question that is now bothering many of us is whether we should expect isolated severe coronavirus infections that jump from animals to humans to become more frequent, or whether the cases we are currently aware of are just the tip of an iceberg of many as yet unknown infections.”
