Erich D. Ryll, M.D., was an Infectious Disease Specialist and Assistant Clinical Professor of Medicine, University of California Davis School of Medicine, Davis, California. Dr. Ryll was appointed chair of the committee to investigate the 1975 Sacramento outbreak of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) that occurred at Mercy San Juan Hospital, California, USA. He coined the term "Infectious Venulitis" or (IVN) to describe the outbreak, though he later considered it a "variant" of ME/CFS. The reason he thought this outbreak was different was because damage to the vascular system was not described in older reports of ME/CFS.
Dr. Ryll followed the patients from this outbreak starting at its onset in 1975 until his death in 2014, making him the longest clinical investigator of ME/CFS in the history of the U.S. He readily admitted, "Because the complaints of patients were so many and often seemingly bizarre, I often attempted to disclaim them as being real. But I learned that you patients were always right and I was always wrong. In studying this disease, one must always have an open mind. This disease teaches the physician to be humble."
In 1984, Dr. Ryll was invited to New Zealand to consult on the 1984 Tapanui & West Otago Outbreak and concluded that this outbreak was the same illness as the 1975 Sacramento outbreak. He, also, believed that epidemic neuromyasthenia, Sick Building Syndrome, Gulf War Illness, epidemic phlebodynia (an epidemic of a painful vein disease in the 1950s and 1960s), as well as many cases of fibromyalgia, are all variations of the same illness.
- 2011, "A 30-Year Historic Review of a Community Hospital Epidemic Outbreak Characterized by Venous Inflammation"
- Patient information handout by Dr. Ryll on Infectious Venulitis, Chronic Fatigue Syndrome, Myalgic Encephalomyelitis.
- Obituary: Sacramento’s Dr. Erich Ryll, 93, early expert on chronic fatigue syndrome.