Do official figures from China accurately reflect the number of people infected by coronavirus? How is the new virus transmitted? And how can an impending pandemic be contained?

Leading German scientists answered some central questions about the latest coronavirus to sweep across the globe, dubbed COVID-19, at an information event organized by the Science Media Center and the National Academy of Sciences Leopoldina in Berlin.

The virus replicates like the influenza virus in the throat, explained virologist Christian Drosten from the Charité University hospital Berlin, which makes it more contagious than initially suspected.

Despite recent reports that pangolins are likely to be the intermediate host of the virus (which is thought to have originated in bats), Drosten said the exact origin of the virus may never be established. 

It is possible, he argued, that the virus was first transmitted to humans somewhere in China before it was spread at the live animal market in Wuhan, where the first cases were reported. 

Disease spread

According to Lothar Wieler, president of the Robert Koch Institute (RKI), previous data indicates that COVID-19 has a similar impact to a severe wave of influenza.

China is taking drastic measures to prevent the spread of the virus beyond its borders, but all the chains of the infection globally have all been linked in some way to China.

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Containment strategy 

The containment efforts made so far in countries outside of China have been "very, very successful," Wieler told event attendees. The doctors in countries outside China, including Germany, are trying to delay a possible wave of the disease. Their intention is to prevent a possible pandemic of COVID-19 from coinciding with the current wave of influenza.

"At some point, it will probably happen that unnoticed infections are suddenly detected," Drosten said, pointing out that the possibilities for containment are limited. 

When does it become a pandemic?

As all cases of the virus outside of China have so far been contained, COVID-19's spread across the globe can't yet be considered a "pandemic." 

In fact, it may never fulfil that criteria, said Wieler. "The decisive characteristic [for a pandemic] is that it spreads to several continents," he said.

Although cases of COVIC-19 have been diagnosed worldwide, none of the known infection chains have gotten out of control — all have been contained within the population.

Figures and fatalities

The number of infectious cases being quoted by the Chinese government should be treated with caution, experts emphasized. "They are trends," said Wieler. According to Drosten, the figures rather reflect the capacities of the reporting system, not the actual numbers, suggesting that many patients with symptoms are never actually registered.

In China, official statistics state the mortality rate is about 2%.

But among all of the cases detected and treated outside China, it's only 0.2%. This is probably due to the fact that only patients with severe symptoms are tested and treated in hospitals in China, Wieler said, pointing out that a more accurate figure is probably closer to 0.2% in China, as outside. 

Drosten emphasized that many sufferers of COVID-19 experience symptoms similar to a common cold or mild flu.

Older patients are more at risk and men are also more frequently affected than women. According to the experts, even people who experience few or no symptoms can infect others.

Is Germany prepared?

If a wave of infection hit Germany, it would likely overburden the health authorities and lead to long waiting times in hospitals, Dorsten said.

But it isn't clear when such a wave would hit, or how intense it would be. In any case, thorough preparations are already underway, according to Charité CEO Heyo Kroemer. If an epidemic were to hit Germany, authorities could, for example postpone non-urgent operations to make room.

As for low income countries outside of Europe, Wieler said an additional pathogen would massivley challenge regional health systems. In preparation, partners in industrial nations have begun sending diagnostic material to lower income countries in the hope of significantly boosting diagnostic capabilities. International experts are also offering training for infection prophylaxis, especially in hospitals.

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Who is to blame? 

Drosten stressed that the spread of a virus like COVID-19 is a natural phenomenon and that pointing the finger at those who are infected is innapropriate and unhelpful. 

What is important is bettering our understanding of the disease and learning how to protect people, he said, especially those who may have underlying diseases or compromised immune systems.

The experts made clear that, in general, thorough hand washing is a reliable precautionary measure, but wearing protective face masks is not, as the humidity generated from breathing renders the masks ineffective after only 20 minutes.

Open questions

It remains unclear how fast the virus is spreading and how many people, on average, an infected person can infect, Wieler said. If doctors knew that, more accurate predictions would be possible — including, for example, an understanding of whether the spread of the virus is likely to gradually roll out across the globe, or strike in waves.