Dr. Björn Sigurðsson[1] (1913–1959) was the first director of Keldur - the Institute for Experimental Pathology, University of Iceland.
Björn died at an early age while having been the director of Keldur for only about ten years.
In his short life, he made many developments in research in the fields of pathology, bacteriology, virology, immunology and epidemiology.
Björn became a world-renowned scientist because of his research on infectious diseases caused by slow viruses.
Mæði is a slowly progressive interstitial pneumonia of adult sheep while visna is a slow, progressive encephalomyelitis and the same virus, belonging, to the lentivirus subgroup of retroviruses, was found to be responsible for both conditions.