The group A streptococcus is a bacterium that can cause a range of infections, from a harmless throat infection to blood poisoning and maternal fever. Calculations show that it is the sixth most deadly microorganism worldwide. However, Nina van Sorge, Professor of Translational Microbiology, believes that this pathogen is not receiving enough attention, as she explained in her inaugural lecture on Thursday June 16th.
A complete picture of an infectious disease is important for reducing the burden of disease. One way of charting the extent of infectious diseases is bacteriological surveillance. According to Van Sorge, this method does not focus on the disease, but rather on the pathogens: "This has already been done since 1959, for example, with pathogens of the serious disease bacterial meningitis, by the Dutch Reference Laboratory for Bacterial Meningitis. By monitoring disease burden and outbreaks, new vaccines have been developed and new bacterial variants are discovered more quickly. Vaccination schedules can then be adjusted accordingly."
Van Sorge would like to see more attention devoted to the group A streptococcus. In April this year, there were alarming reports in the newspaper about an increase in the number of serious infections with this pathogen, especially among children. "And we believe that the burden of disease in the Netherlands is not so great. According to calculations, half a million people die worldwide each year from infections caused by the group A streptococcus." Yet there is a great lack of interest in this bacterium, she points out: "There is only a reporting obligation for three syndromes, while the bacterium can cause many more life-threatening conditions."
To gather more information on the disease burden of the bacteria, Van Sorge's group, together with colleagues from St. Antonius Hospital in Nieuwegein, UMC Utrecht and RIVM, started bacteriological surveillance of group A streptococcus in 2019. Although a vaccine is not expected for another ten years Van Sorge hopes that sufficient information about group A streptococcus will be collected so that by that time a well-considered decision can be made whether or not to introduce a vaccine. Based on bacteriological surveillance, a decision can for example be made much earlier to treat household members of infected persons with antibiotics as a precautionary measure to prevent them from spreading.
Still plenty of questions
For Van Sorge, there are still many questions surrounding pathogens such as the group A streptococcus that she hopes to answer with fundamental research in the future. For example: why does a bacterium keep quiet in one person, while another gets sick? Van Sorge: "With my chair of translational microbiology we approach this question from two sides. We look at it from the bacterium's perspective: is the disease caused by specific characteristics of the bacterium? But we also investigate whether the host has gaps in the defence against a certain bacterium that increase the risk of a serious infection. In addition, in the future I will focus more on the protective role of the microbiome: which micro-organisms can we use to influence the immune system to increase our resistance to infections?”
Intensive cooperation with clinical doctors, patient associations and scientists from other disciplines is necessary to solve complicated puzzles like this, according to Van Sorge: "It is not an individual sport; it is really a team sport."