Resistant bacteria that cause difficult-to-treat infections are among the greatest challenges facing infectious diseases expert Annelies Zinkernagel in her daily work at the UniversityHospital Zurich.
Text: Thomas Gull
Translation: Philip Isler
In Switzerland, every year some 300 patients succumb to infections caused by bacteria that are resistant to antibiotics. Unfortunately, with resistance to antibiotics on the rise, this number is growing. Already there is resistance to what are known as “reserve” antibiotics, which are only used as a last resort to treat infections with no other treatment options.
The quandary here is that the main contributing factor to the spread of antibiotic resistance is, in fact, the use of antibiotics itself. Here’s why: Normally, the bacteria on our body, in our gut or on our skin are in balance. When we are given antibiotics, it not only kills off the “bad” bacteria such as Staphylococcus aureus, but also the “good” ones, for example those that help us digest our food. And there’s more: Eliminating the good kind of bacteria means less competition for the bad, resistant kind, and they can then spread unhindered. That is why it is often said that “antibiotics breed resistance”.
Mitigating the damage
The most important strategy to curb the spread of resistance is thus a targeted and moderate use of antibiotics. This goes for human medicine as well as veterinary medicine. Since 2015, efforts under the Swiss Antibiotic Resistance Strategy (StAR) have sought to reduce the use of antibiotics – in humans as in animals. In human medicine, there are antibiotic stewardship programs, which promote proper use of antibiotics. “Our aim is to limit the damage as far as possible,” says Annelies Zinkernagel, who heads up the Department of Infectious Diseases and Hospital Epidemiology at the UniversityHospital Zurich.
In other words, antibiotics should only be used when they are really needed, and only in a highly targeted manner. For medics to be able to do so, they first have to find out whether an infection was caused by bacteria or viruses, and they have to check whether the infection was brought about by bacteria that are already resistant. “It’s important here to work hand in hand with GPs,” emphasizes Annelies Zinkernagel. GPs also make sure to find out what caused the infection before administering antibiotics. “They’re doing a great job,” says Zinkernagel, commenting on her colleagues in the local communities. The message that antibiotic resistance is no laughing matter seems to have caught on.
Sweden green, Greece red
Campaigning and raising awareness pays off, as seen in the Scandinavian countries, where resistance is currently much lower. The Surveillance Atlas of Infectious Diseases map of resistance to S. aureus, for example, reveals a gap between the North and South, with Scandinavia showing up green with low resistance levels, Central Europe in yellow, and the countries in Southern Europe, including Italy and Greece, colored red. “This is no surprise if you know that in Greece, for example, antibiotics are available over the counter without a prescription,” says Annelies Zinkernagel. As a result, resistant bacteria are often inadvertently brought back home from the holidays – as “travel souvenirs”, so to speak. A second important element besides the targeted use of antibiotics is prevention. For example, this means that high-risk patients should get vaccinated against the flu. “Fewer viral infections also mean fewer bacterial infections,” says Zinkernagel. It often happens that patients first have a viral infection, but later succumb to a bacterial infection that they acquired because their immune system was weakened by the viral infection. Vaccines against pneumococcal infections such as pneumonia are also available.
People may catch an infection in a hospital, for example during an operation, where the body’s natural barriers (like the skin) against bacteria are compromised. Or bacteria are introduced into the body through materials and then enter the bloodstream. After all, resistant bacteria can also be found in hospitals, where they may spread to patients. “If they’re unlucky, this can result in an infection,” says the infectious diseases expert, while stressing that this doesn’t happen very often in Switzerland. This is why hospital hygiene has a major role to play in preventing infections and the stopping the spread of resistant bacteria.
The antibiotic resistance epidemic can only be kept in check if everyone works together, emphasizes Annelies Zinkernagel. This is why the One Health approach is so important, as it combines human medicine and veterinary medicine, while also investigating the role of the environment in the spread of antibiotic resistance. “Only by addressing each of these areas together as a whole can we prevent antibiotic resistance from becoming an even greater problem.”