The pathogen is a virus from the group of the corona viruses . “We have known this virus group for many years. Says Professor Marylyn Addo from the University Medical Center Hamburg-Eppendorf (UKE). Corona viruses can trigger harmless colds, but also serious illnesses such as Sars or Mers.
The novel virus is called Sars-CoV-2 because it is very similar to the Sars pathogen. So far, it has been assumed that the virus has passed from an animal which is unclear to humans. Since then, it has spread from person to person. The origin of the pandemic is a now closed fish market in the Chinese metropolis Wuhan, where wild animals were also offered.
How is the corona virus transmitted?
The initial assumption that the virus can only be transmitted by people who are already showing symptoms has been refuted. “The pathogen can also be transmitted during the incubation period ,” says Marylyn Addo. The incubation period refers to the time until the disease breaks out after infection. With Sars-CoV-2 it is one to 14 days, on average five to six days.
According to previous knowledge, the transmission takes place primarily via droplet infection:
- to cough
So an infected person sneezes, another inhales the flying droplets and they reach the mucous membranes of the respiratory tract. Transfer through the hands is also possible. Scenario: Someone sneezes in the hand, touches a door handle, the next one touches the handle immediately afterwards and then in the face – for example in the mouth or nose.
According to current knowledge, Sars-CoV-2 is a very contagious virus. It is assumed that an infected person infects between 2.4 and 3.3 more.
Mortality Rate: How Dangerous is the Corona Virus?
The so-called lethality, i.e. the mortality rate , cannot currently be reliably determined. Because all infected people would have to be recognised. If many cases are not discovered, the lethality is overestimated – in reality it is lower. In the case of Sars-CoV-2, many cases could go undetected because a large part of the infections are very mild and some people show no symptoms at all.
Currently, Covid-19 mortality differs from country to country. The mortality rate in the region most affected by the outbreak in Hubei in central China was 4.46 percent last week, and 0.86 percent in the rest of China. In Germany it is currently (as of March 17, 9:00 a.m.) 0.2 percent.
There can be different reasons for the fact that the lethality sometimes differs greatly. In addition to differences in testing – such as how widely testing is carried out – this can also be due to the condition of the health system and the question: How well are the patients cared for? The age structure of a society can also play a role – the older the society, the more people from the risk group are part of it. People aged 80 and over are particularly at risk for a severe course with Covid-19.