How long do the viruses on door handles last? How do I know that I am infected? Can you get infected again if you've ever had Covid-19? Answers to the most important questions.
Researchers believe that Sars-CoV-2 has passed from animal to human - possibly at a market in the Chinese city of Wuhan where many wild animals have been traded.
It is not yet clear which animal originally carried the virus. The genome of Sars-CoV-2 is closely related to coronaviruses, which researchers found in bats in eastern China. Based on bats, the pathogen could have infected other animals before it got to humans. So-called pangolins are considered to be such an intermediate host
Sars-CoV-2 is transmitted from person to person. According to the current state of knowledge, the viruses get from one person to the next via droplets when coughing or sneezing. The virus can also be transmitted indirectly, for example by coughing an infected person in the hand and touching an object. Theoretically, healthy people can then become infected with this object (see next question). Since the genetic material of the virus was found in stool samples from some patients , it was initially thought that they could also spread via the so-called fecal-oral route of infection. An investigation has refuted this thesis:
"We also treated it in cell culture and checked whether living, infectious virus can still be extracted from these samples in the laboratory," said virologist Christian Drosten. "That was not the case. In contrast to the lung secretions or the swabs, where we also extract live virus, we cannot extract live virus from stool samples."
There is still no exact answer to this question. The Robert Koch Institute (RKI) writes that transmission in this way has not yet been documented and adds: "An infection with Sars-CoV-2 over surfaces that do not belong to the immediate surroundings of a symptomatic patient, such as imported goods , Mail, or luggage seems unlikely. "
New laboratory experiments have now shown that Sars-CoV-2 can last up to three days on certain surfaces - such as plastic or stainless steel. The U.S. researchers, who previously published their study, also found in their study, which has not yet been confirmed by independent experts, that the coronavirus can last up to four hours on copper, up to 24 hours on cardboard and up to three hours in fine particles in the air (aerosols) is infectious.
In contrast to bacteria, viruses do not have their own metabolism, but need a living cell to multiply: a so-called host cell. The stability of viruses outside of this host depends, among other things, on factors such as temperature, humidity and the nature of the surface. Enveloped viruses, which also include Sars-CoV-2, can be better removed using disinfectants and soap than uncovered viruses.
If infectious droplets get onto objects such as doorknobs, armrests or cash and are touched by healthy people, the virus can theoretically be transmitted. Washing your hands offers the best protection.
