Reduction of unnecessary medical interventions in infectious diseases

Research Group Dr Christian Kahlert

Our research focuses on the topic of: Which medical interventions (diagnostics, therapy and prophylaxis) have become redundant as a result of new findings and can therefore potentially harm our patients. Or simply asked: When is less more? Specifically, we are currently investigating vertical transmission of infectious diseases, HIV, immune function, and respiratory infections including COVID-19.

Current research activities

Vertical transmission of HIV

What measures are necessary?

Three current studies examine the consequences of the change in recommendations for preventing the transmission of HIV from women to their children in Switzerland since 2018. The effect of discontinuing neonatal postexposure prophylaxis with zidovudine on blood formation in children in the first two years of life is examined. Furthermore, the frequency of severe infections as well as the immunological functions of these children will be analysed. In addition, factors that influence breastfeeding in mothers living with HIV will be investigated, as well as the consequences for the children of these mothers.

Treatment simplification for HIV

Is a 2-drug regimen sufficient?

A multicentre, prospective, and controlled trial (virtual optimal control) is being conducted to investigate whether dual therapy with nevirapine and 3TC is sufficient to completely suppress HIV viral load.

Pneumococcal respiratory infections

Which factors influence the colonisation and invasion of bronchial epithelial cells by pneumococci? (in cooperation with Prof. Dr. Werner Albrich)

In a human ALI (air-liquid-interface) cell culture model with primary bronchial epithelial cells, we are investigating the pathogenesis of pneumococcal infections from colonisation to invasive infection (collaboration with Prof. Jorge Vidal, University of Mississippi). Another collaboration is with the EMPA of the ETH (group Dr. Peter Wick, Head Particles-Biology Interactions Lab) on the influence of nanoparticles on pneumococcal infections. A current project is investigating the role of tight junctions between epithelial cells.


SURPRISE+ study (in cooperation with PD Dr Philipp Kohler)

Since August 2020, we have been investigating immunity to SARS-CoV-2 in hospital staff from all over German-speaking Switzerland as part of a multicentre cohort study. Through repetitive serology determinations and electronic questionnaires, we are able to answer questions about the frequency of the disease, routes of infection and duration of immunity. We are also interested in questions about the COVID-19 vaccination and Long-COVID. The platform that has been built up over the last few years allows us to better understand other infections for hospital staff. Surveillance for respiratory syndromes, a survey on antibiotic resistance and sero-epidemiological studies on other infectious diseases (e.g. tick-borne encephalitis) are planned.

Corona Immunitas (national initiative, responsibility for cantons St. Gallen and Graubünden)

Investigation of a random selection of the general population of the cantons of St. Gallen and Graubünden. The focus is on the risk of infections through household contacts, the role of children and the comparison with hospital staff.

Immune functions against SARS-CoV-2 in tumour patients

In a collaboration with the Oncology Department at the Cantonal Hospital St. Gallen, antibodies and T cells directed against the virus are being investigated in patients with multiple myeloma or solid tumours.


Research database

On the KSSG research database you will find more detailed information on the individual research projects and publications of the working group.