No viral feedback

DW: What's your analysis of the profile of the people who have contracted the worst form of this novel coronavirus?

Christian Drosten: If we look at those patients that have shown up outside the region where the diseases seem to [have originated], there is a bias toward people who are quite well-off, who can afford medical treatment outside of the country, and usually these are males.

And what's the significance of their being well-off - is it because they are traveling that they are more at risk?

The observation here is more a look at the distribution of the characteristics of patients. So, if we observe a propensity of those cases in males, and those that are quite well-off, it suggests that either the virus prefers this certain type of patient, which is probably not true because it just infects humans, or as an alternative explanation there must be some skewed kind of reporting of cases.

Well, we know that this form of the coronavirus dates back to at least the last few months of 2012, and it's thought to have started off in Saudi Arabia. So, what has your experience been with officials in Saudi Arabia, the people who are investigating this virus there? Your lab has sent materials to Saudi Arabia…

Yes, but this is not only true for my lab, but for several labs across Europe… We are all really trying to collaborate and provide materials, diagnostic tests and also assistance. But what we don't really see is feedback in terms of samples for investigation. Because it's what we really need to do. We need to look at the virus - especially if we are concerned that the virus could evolve. The virus could change and optimize itself and spread more efficiently. Obviously, we need to look at the virus over time, how it develops, and we need samples for that.

So, you're not getting the samples - you must be requesting the samples - but are they reluctant or refusing to send samples?

It's difficult to find a reason for this. But the fact is, we're not getting our hands on samples - it is very difficult and it may be for different reasons. There are concerns that there may be a political unwillingness to share material, but it could also be just the complexity of the system - it's a very large country, there's a large number of laboratories, and different levels of specialization among laboratories, then there are shipping restrictions, and so on. So, the solution to the whole thing is of course to establish lab capacity there, in the country, but this is a process.

But is it also your feeling that there are certain tests that are not taking place locally in the Gulf States?

Well, it's very clear that we have a lack of cross-sectional studies in normal populations. Those cases that you see now, they are hospitalized cases with an underlying disease, and they are severely ill. So, the patients show up very ill, and that's when you start investigating. But actually what has to be done is to go prospectively and proactively and take cross-sections through the population, to test a few thousand representative people of all age groups. And the test for this would be serological tests, which are not so easy to perform for this type of virus. So, it's very clear that the laboratories there would need international assistance to do proper serological testing because this is really a different type of work in the laboratory.

How is it different?

If you have a patient who is severely ill, you can take a sample from the air, put it in a machine and you will get a result because you'll see the virus. But what we need to look for in a cross-section of the population would be the antibodies of the virus, and that's much more difficult because we have other human coronaviruses causing mild respiratory diseases and these viruses trigger antibodies in the blood of almost everybody because we've all be infected with these viruses, and those antibodies will cross-react, so they will generate false positive test signals if you're not very careful and very capable in the laboratory.

Now, while you've raised the possibility of there being milder variants of this coronavirus, and therefore more cases than we're aware of, you've also indicated the urgency of this matter - because at first the World Health Organization was very careful about whether it should call this a SARS-like coronavirus, but there are very clear similarities. And this could be the very start of a very big thing?

Well, the reason why experts are concerned is that these viruses are indeed related. This virus is not the SARS agent, but it's a rather close relative to the SARS agent. It's a different species, but still in the same genus of virus. But there are other viruses, including those in the same genus, which in most of the cases cause harmless infections. At any given point in time, you will find in intensive care wards across countries like Germany, France, England, you will find patients in severe conditions, caused by those otherwise harmless viruses. So, it's not unusual that a harmless virus, that shows itself to be like a common cold in most patients, may affect a few patients severely. And it's conceivable that those patients that we're currently seeing are just that tip of the iceberg.

Prof. Dr. Christian Drosten heads the Institute of Virology at the University of Bonn Medical Center.