Are bacteria sometimes useful for our body

"Viruses also have good sides"

The flu comes to humans via wild birds, SARS via crawling cats - how many infectious diseases are based on animal viruses?
Every virus in humans is a so-called zoonotic virus. This is how we refer to viruses that are transmitted from animals to humans and against which they have not yet developed any defense mechanisms. The only question is how long ago that was. With some viruses, this happens every year. For others, it was thousands of years ago.

Are there animals that are particularly often the trailblazers for our diseases?
Yes, especially if you live in large social organizations. Like the birds from which influenza viruses spread. Our focus is on bats. Among the mammals, they are the only ones who live by the hundreds of thousands in a cave - like us in large cities. The larger and denser the population, the more likely it is that the random mutation that causes the virus to jump from animals to humans is likely to happen. Mammals are genetically close to us, which makes it easier to switch hosts. Field tests in bat caves actually reveal the precursors of our childhood disease viruses, such as measles and mumps.

And the future viral diseases for humans also lurk in the caves?
We'll start from that and prepare by looking to see what kinds of viruses are there. The challenge is to be able to read it, to recognize it as a virus - just like an archaeologist has to decipher hieroglyphs. Field research takes us further: catching animals, taking samples, identifying DNA, documenting. The more we see, the better we can assess unknown viruses.

How can you prepare for epidemics?
It is a social task: the state should protect people from reactor accidents, the same applies to pandemics. That justifies that Germany is more involved abroad, the disease is happening worldwide. It's about improving hospitals, promoting development aid in agriculture and nature conservation.

What can individuals do to protect themselves?
Get vaccinated against influenza, for example. You make a contribution to society and in many cases it helps you, the process is milder. To protect against everyday infections such as colds, I advise wearing gloves on public transport, especially in winter. The viruses sink into the fabric. You don't even have to wash your hands all the time.

One gets sick, the other is spared. What does it depend on?
One factor is the dose of the virus. It often decides whether it remains with a sore throat or pneumonia. By the way, adults do not excrete that many viruses, you do not necessarily get infected from people sitting next to you on the plane. It looks different with small children: In comparison, their nasal secretions contain a hundred thousand times as much viruses. It has been proven that anyone who deals with children has more infections. Then it comes down to individual genetics and immunity: Have I had contact with a similar virus before? Today we know why the Mexican flu, the swine flu, was comparatively harmless in 2009 - everyone born before 1957 had something to do with the H1N1 virus in a very similar form.