A quiet crisis manager

© © Universitätsspital Basel

Sarah Tschudin Sutter researches how hospitalised people can be protected against infection with, in particular, antibiotic-resistant pathogens. She was a Covid-19 Task Force member and is still an advisor to the Swiss government.

Sarah Tschudin Sutter is used to making quick decisions in emergency situations. And she had to do just that in March 2020, when she received a call from Matthias Egger, President of the National Research Council. He was in the process of setting up the Swiss National Covid-19 Science Task Force on behalf of the federal government and was looking for an expert in infections (and in the prevention and control thereof). Shortly before that, the Federal Council had ordered a lockdown, events in Europe were reaching fever pitch, and images of vehicles queuing to transport coffins out of hospitals in Bergamo were terrifying the population.

As an infectious diseases expert, Sarah Tschudin Sutter agreed immediately, even if she couldn't know what the ensuing pandemic might confront her with. "My specialist field was suddenly at the centre of attention, and I wanted to do my part in helping to overcome the crisis," says Professor Tschudin Sutter (now 46). "But those members of the Task Force who at the same time were working in hospitals were under particularly heavy pressure, as the burden of work in hospitals was also growing significantly."

Lesson learned in Kuwait: hospital hygiene matters

Professor Tschudin Sutter is not one of the more vocal members of the Task Force. She was seldom in the limelight, and she found it difficult dealing with the media. In charge of hospital hygiene at Basel's University Hospital and professor of epidemiology of infectious diseases at the University, she is cautious and chooses her words carefully. She doesn't trumpet her achievements. The occasional and slightly embarrassed giggle even suggests that she doesn't relish talking about her successful career. Her decision over 20 years ago to study medicine was a purely rational one: in fact it was really biology that fascinated her. "But I wanted to train for an actual job – something concrete." Although her parents were initially anxious that such a demanding course of study would overtax her, she enjoyed her studies.

Her passion for research and infectiology arose during her training as a specialist physician. As a postdoc in 2011 she received a grant from the Swiss National Science Foundation to attend the prestigious Johns Hopkins Hospital in Baltimore for two years. It was there that she obtained her Master's degree in epidemiology. "The change of perspective proved valuable." She got to know a different health system: in Baltimore, the problems associated with crime and poverty were much more acute than in Basel. She also likes to look back on her three visits to the Adan Hospital in Kuwait, which received advisory support from the US hospital. "The hospital was more or less in the middle of the desert," recalls Professor Tschudin Sutter. "Due to the heat, the infrastructure weathered quickly and it was difficult to implement preventative and anti-infection measures." Modern diagnostics were lacking, hand hygiene was often inadequate, and multi-resistant pathogens multiplied rapidly. There, Tschudin Sutter experienced the drastic consequences of inadequate hospital hygiene at first hand.

Resistant germs invade the wards

In 2013, Sarah Tschudin Sutter returned to Basel University Hospital to assemble her first research team – again with various grants from the SNSF. Later, she was also appointed Professor there. The main focus of her research work is the spread of pathogens resistant to multiple antibiotics in hospitals. She is currently working on a special group of bacteria known as ESBL-producing Eenterobacterales. "When I was first working in hospital hygiene in 2009 I only encountered these bacteria in the hospital quite rarely. But since then they have spread rapidly." Though not posing a threat to healthy people, they can prove fatal in the presence of infection – for example during an operation.

For a long time, experts had assumed that patients mainly became infected with Enterobacterales in hospitals due to poor hygiene. Then the epidemiologist Tschudin Sutter set about researching the causes in a large-scale study. For two years, her team analysed samples of wastewater from the University Hospital as well as water taken from various locations along Basel's sewers. The result came as a surprise: ESBL-producing Enterobacterales were present in 96 percent of the effluent samples. Sequencing of the bacterial genes and comparisons with samples from the University Hospital's archives enabled the researchers to establish whether patients had picked up the Enterobacterales in hospital or had brought them in from outside. Professor Tschudin Sutter sums up the results thus: "There is a lot of evidence to suggest that the bacteria multiplied mainly outside the hospital."

The second main focus of the research is on hospital hygiene. The epidemiologist recently carried out a study on hand disinfection, as contaminated hands have until now been regarded as the chief route by which hazardous germs are transmitted in hospitals. The WHO suggests six steps to ensure that hands are properly disinfected. "Very few people can even remember all these steps, so it's not really feasible to adopt the method in day-to-day hospital practice," the researcher explains. She has therefore tested a method consisting of just three steps. In her trial, two groups of students first dipped their hands in a solution full of bacteria and then cleaned them, with one group adopting the 3-step method and the other the 6-step method. "The results from both groups were comparable," says Tschudin Sutter. The new method was subsequently introduced at Basel University Hospital, where it continues to be monitored scientifically. The WHO is currently considering whether it should modify its global recommendation for a 6-step method.

Still a Covid-19 advisor

When the Covid-19 Task Force was wound up in March 2022, Professor Tschudin Sutter was initially glad to at last have more time for her own research again. But it didn't take long for the next request to arrive: Tanja Stadler, biostatistician at ETH Zurich and head of the Scientific Advisory Panel set up to succeed the Task Force, chose the Basel-based infectious diseases specialist as one of 14 researchers to continue advising the federal government. "I obviously wondered if I should let myself in for that again," admits Professor Tschudin Sutter. After all, her private life as well as her own research work had suffered during the pandemic. At that time, she virtually only saw her husband – a neurologist and intensive care specialist working in the University Hospital's intensive care unit – when taking short breaks in the hospital. But she nevertheless has the following to say about it: "During the pandemic I worked together with experts who I would have never got to know otherwise, and that was very rewarding."