At the beginning of the Corona outbreak, the news was calming. The virus is not so contagious, it probably only affects the lower respiratory tract, which mainly includes the lungs, it said. New findings now show that the researchers were wrong. There are many indications that the pathogen can spread similarly to the flu – and is therefore significantly more infectious than initially thought.
“We are currently learning something about the properties of the virus and the course of the disease that we did not know a week or two ago,” said Christian Drosten of the Charité at a press conference in Berlin. The most important thing at the moment is the realization that the virus can multiply in the throat.
“Throughout January, Sars was still used as a model for the new virus,” said Drosten. Because of the great similarity to the novel corona virus, scientists assumed that both would be transmitted in similar ways. New findings contradict this: “We can now say that the transferability of the new virus is higher than initially thought,” said Drosten.
The novel corona virus has it much easier
The receptors for the Sars virus are located deep in the lungs. If it wants to infect a person, it must reach this point with the air we breathe. “It’s a long way,” says Drosten. It then takes some time for the virus to spread to the lungs and be excreted. The novel coronavirus Sars-CoV-2 has it much easier in this regard.
As tests in Germany have shown, the viruses can already attach and multiply in the throat. Their path out of the body is correspondingly shorter. “We were able to replicate viruses from a throat swab even in patients who had only had cold symptoms for a few days and shook themselves from time to time,” says Drosten. “Sars never succeeded.”
In this regard, the novel coronavirus is more similar to seasonal flu, which causes thousands of infections every spring in Germany. It can also multiply in the throat and then be transmitted by droplet infection, for example when sneezing and coughing.
Current estimates: As fatal as the flu
Drosten also makes comparisons with the flu on another point: According to current information – at least as far as the cases outside of China are concerned – the virus is just as dangerous as influenza. While in the epicenter of the Covid-19 epidemic, according to official figures, around two percent of patients die, the mortality outside of China is around 0.2 percent. This value is similar to that of previous global outbreaks of flu.
At the same time, Drosten points to large gaps in knowledge that still exist. For example, estimates of what percentage of the population in the particularly affected Hubei region are currently ill are missing. “Knowing this rate will also make it easier to predict the speed at which the virus will spread,” said Drosten.
If a pandemic develops from the outbreak in China, it could, according to the current state of knowledge, proceed similarly to flu pandemics in the past. However, one cannot yet speak of a pandemic, said Robert Wieler, head of the Robert Koch Institute. “We are currently unable to predict the dynamics of the outbreak.” It is conceivable that a wave of infection could also occur in Germany.
“In 2017/18 we had a very severe flu wave with around ten million visits to the doctor – this has shown us that our health system is capable of managing such outbreaks,” says Wieler. If Covid-19 should actually become a problem in Germany, it will be a challenge above all to decouple it from the flu wave.
On Wednesday, one of the German coronavirus patients was discharged from the Schwabing clinic in Munich after several tests had failed. Eight other patients are being cared for in the Bavarian clinic, so their clinical condition is stable. A total of 16 infections are known to date in Germany, including 14 in Bavaria.