Burden of disease associated with antimicrobial resistance. Studies on bloodstream infections and clinical outcomes in European hospitals

PhD ceremony: Ms. M.E.A. de Kraker, 14.30 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Burden of disease associated with antimicrobial resistance. Studies on bloodstream infections and clinical outcomes in European hospitals

Promotor(s): prof. H. Grundmann

Faculty: Medical Sciences

Monitoring the spread and impact of antimicrobial resistance remains important, but the fear for a return to the pre-antibiotic era is premature at this point. The total number of patients dying from infections due to resistant bacteria is relatively small, as compared to chronic diseases, like cardiovascular disease, or infections caused by antibiotic-susceptible bacteria. These conclusions are drawn in the thesis of Marlieke de Kraker, epidemiologist at the Netherlands’ National Institute for Public Health and the Environment.

Excessive use of antibiotics has resulted in the development of resistance in disease-causing bacteria. In the BURDEN project, patient data were collected from thirteen hospitals across Europe to determine the clinical impact of antimicrobial resistance. The study specifically focused on methicillin resistant Staphylococcus aureus, MRSA, and third-generation-cephalosporin-resistant Escherichia coli. Patients with bloodstream infections caused by these multi-resistant pathogens died more often and had a prolonged hospital admission, compared to patients infected by susceptible bacteria. In 2007, in Europe more than 8,000 patients died from such antibiotic-resistant infections, which is approx. two people per 100,000 inhabitants. In comparison, infections by antibiotic-susceptible bacteria are more common, and the number of associated deaths is twice as high. Chronic diseases, such as cardiovascular diseases, easily outweigh these figures (373 deaths per 100,000). The number of bloodstream infections has markedly increased through the emergence and spread of antimicrobial resistance. This is mainly associated with resistance development among bacteria that are present in the normal human gut flora. It therefore remains important to monitor resistance development. Another important development is the increasing number of hospitals having to deal with outbreaks of almost untreatable infections caused by carbapenamase-producing bacteria. Future studies need to define the impact of these pan-resistant pathogens and the prevention of outbreaks.