Digital Public Defence: Petter Elstrøm

MPH Petter Elstrøm at Institute of Health and Society will be defending the thesis “The epidemiology, prevention and control of methicillin-resistant Staphylococcus aureus (MRSA) infections and colonisations in Norway” for the degree of Dr. Philos. (Doctor Philosophiae).

Image may contain: Glasses, Hair, Facial hair, Forehead, Beard.

Photo: Norwegian Institute of Public Health

The public defence will be held as a video conference over Zoom.

The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

Click here to participate in the public defence

Download Zoom here

Digital Trial Lecture – chosen topic - time and place

See Digital Trial Lecture on a chosen topic.

Digital Trial Lecture – given topic - time and place

See Digital Trial Lecture on a given topic.

Adjudication committee

  • First opponent: Avdelingsoverlege Iren Høyland Löhr, Stavanger universitetssjukehus, Helse Stavanger HF
  • Second opponent: Seksjonssjef Karl Pedersen, Avdelningen för djurhälsaog antibiotikafrågor, Statens Veterinärmedicinska Anstalt, Uppsala, Sverige
  • Third member and chair of the evaluation committee: Professor Morten Lindbæk, Universitetet i Oslo

Chair of the Defence

Professor Per Nafstad, University of Oslo


Staphylococcus aureus can cause a range of diseases and is one of the main causes of nosocomial infections. Methicillin-resistant S. aureus (MRSA) is associated with increased morbidity and mortality compared to methicillin-sensitive S. aureus (MSSA).

The aim of the thesis is to describe the epidemiology of MRSA in Norway and assess the consequences of both MRSA dissemination and control. The research is based on data from National registries and outbreaks investigations, supplemented with a review of published guidance, regulations and registered enquiries to the Norwegian Institute of Public Health.

The incidence rate of notified MRSA has increased during the last 12 years. In the last three years up to 2017, the numbers of infections have plateaued while colonisations have continued to rise. Our analyses indicate that the rise of colonisation is influenced by increased search for MRSA. In addition, a rising number of persons have acquired MRSA abroad. Further transmission in Norway after import, is limited. Most persons were reported colonised or with non-severe infections. We found a 30 days all-cause mortality rate of 20% after diagnosed with MRSA bacteraemia, which is not higher than expected after bacteraemia caused by MSSA.

The results indicate that the MRSA interventions are effective in agriculture and in nursing homes. In hospitals, the incidence rate of infections has increased, but the annual number of persons related to hospital outbreaks of MRSA has not changed during the last 12 year.

Although the results indicate that Norway have prevented MRSA from becoming an increasing public health problem, we do not have enough knowledge of the effects and side effects of the interventions applied. Some restrictions imposed may come in conflict with ethical norms, laws and regulations, including the human rights. The national MRSA guidelines should be subject to a revision where the goal is to maintain the preventive effect and minimize the risk of burden of each intervention.

Additional information

Contact the research support staff.

Published May 15, 2020 12:55 PM - Last modified May 29, 2020 11:03 AM