Three years after Winge's publication, Hjalmar Heiberg, professor of anatomo-pathology from Norway, reported similar findings. He described the case of a 22 year old female who became critically ill ten days after childbirth. She developed signs of sepsis with fever, chills, articular pain, and erysipeloid skin lesions. Within a few weeks, her clinical situation deteriorated and she died.
At autopsy, Heiberg observed a mitral valve "ulcerative endocarditis" with multiple vegetations. He also noted multiple infarcts in the kidneys and spleen. His microscopic examination of the valve suggested the presence of a parasitic organism, Leptothrix. Similar to Winge, he named this affection "Mycosis endocardii".
The specimen was sent to Virchow, the famous German pathologist, who did not agree with Heiberg's findings and described these microorganisms as "vibrions".
It is important to note that the staining methods for the classification of microorganisms were not described in 1872.
In the second half of the 19th century, pathologists were able to isolate these microorganisms with an increasing frequency in valvular specimen affected by "Mycosis endocardii". The accumulation of this evidence led Klebs, one of the founders of microbiology, to propose in 1878 that "all the cases of endocarditis are of mycotic [infective] nature."