Over the years, time and time again infection has been put forward as being the cause of multiple sclerosis. In 1894 Pierre Marie, a former student of Jean Martin Charcot, the father of neurology, argued strongly that infection was the cause of multiple sclerosis. He did not know the specific infective agent but was certain that a treatment would soon be available in the form of a "vaccine of Pasteur or lymph of Koch." Over the years many agents have been put forward but none have been proven.
In 1960, the following paper was presented: (Compt Rendu Acad Sci Paris.)
The Rickettsia are Gram-negative, obligate intracellular bacteria that infect mammals and arthropods. These organisms are small, pleomorphic coccobacilli about 2 µm in length. Their structure is typical of Gram-negative bacteria. What are here referred to as neo-rickettsioses and in some later papers as para-rickettsioses are in fact the chlamydiales, which at the time did not include chlamydia pneumoniae because it had not yet been isolated as a pathogen.