This list spans the years 1934-1990. There have reputedly been outbreaks since 1990 in the Middle East, Eastern Europe, and Asia, but documentation is lacking. (Please feel free to contact me if you know of any additional outbreaks that can be documented.)
It is important to keep in mind that many diseases occur in both epidemic and sporadic form. Polio was sporadic for many years before it became epidemic. Polio is now, once again, sporadic. The bubonic plague, which wiped out a third of Europe's population in the 14th century, still exists today in sporadic form.
Epidemics of ME/CFS
1934 Los Angeles City and California State, USA: Epidemic among personnel at L.A. County Hospital, Ruth Protection Home and throughout California, paralleling poliomyelitis, often diagnosed as atypical poliomyelitis.
1936 Fond-du-Lac, Wisconsin, USA: An outbreak of "encephalitis" in St. Agnes Convent.
1937 Erstfeld, Switzerland: Outbreak described as "Abortive Poliomyelitis."
1937 St. Gallen, Switzerland: Outbreak in Frohburg Hospital described as "Abortive Poliomyelitis."
1939 Middlesex, England: Outbreak at Harefield Sanatorium - "Persistent myalgia following sore throat."
1939 Degersheim, St. Gallen, Switzerland: Outbreak described as "Abortive Poliomyelitis."
1945 University Hospital of Pennsylvania, USA: Epidemic described as "pleurodynia with prominent neurological symptoms and no demonstrable cause."
1946-7 Iceland: "Mixed epidemics of poliomyelitis and a disease resembling poliomyelitis with the character of the Akureyri Disease."
1948-9 North Coast Towns, Iceland: "A disease epidemic in Iceland simulating Poliomyelitis" in three separate towns.
1949-51 Adelaide, South Australia: Outbreak of a disease resembling poliomyelitis.
1950 Louisville, Kentucky, USA: Outbreak in the Nurse's Training School of St. Joseph Infirmary, later described as "epidemic neuromyasthenia."
1950 Upper New York State: Outbreak described as resembling the "Iceland Disease...simulating Acute Anterior Poliomyelitis."
1952 London, England: Outbreak at Middlesex Hospital Nurses' Home described as "Encephalomyelitis associated with Poliomyelitis Virus."
1952 Copenhagen, Denmark: Outbreak described as "epidemic myositis."
1952 Lakeland, Florida, USA: Outbreak described as epidemic neuromyasthenia.
1953 Coventry and Coventry District, England: "An illness resembling Poliomyelitis observed in nurses."
1953 Rockville, Maryland, USA: Chestnut Lodge Hospital student nurses described with poliomyelitis-like epidemic neuromyasthenia.
1953 Jutland, Denmark: Outbreak of "Epidemic encephalitis with vertigo."
1954 Seward, Alaska: Outbreak described as "Benign Myalgic Encephalomyelitis (Iceland Disease)."
1954 Berlin, Germany: Among the British Army, a "further outbreak of a disease resembling poliomyelitis."
1954 Liverpool, England: Outbreak among medical and nursing staff in a Liverpool Hospital.
1955 Dalston, Cumbria, England: "...an unusual disease seen in epidemic and sporadic form in general practice in 1955 and subsequent years."
1955 London, England: Outbreak of benign myalgic encephalomyelitis among Royal Free Hospital staff.
1955 Perth, Western Australia: "Virus epidemic in recurrent waves."
1955 Gilfach Goch, Wales: Outbreak of Benign encephalomyelitis.
1955 Durban and Durban City, South Africa: Outbreak among nurses at Addington Hospital called "The Durban Mystery Disease" describing neuromuscular dysfunction, and epidemic myalgic encephalomyelopathy, including sporadic cases in Johannesburg of a outbreak resembling poliomyelitis.
1955-6 Segbwema, Sierra Leone: An outbreak of encephalomyelitis.
1955 Patreksfordur and Thorshofn, Iceland: Unusual response to poliomyelitis vaccination.
1955 North West London, England: Outbreak of acute infective encephalomyelitis simulating poliomyelitis among a residential home for nurses.
1956 Ridgefield, Connecticut, USA: An epidemic of neuromyasthenia.
1956 Punta Gorda, Florida, USA: An outbreak of epidemic neuromyasthenia.
1956 Newton-le-Willows, Lancashire, England: Outbreak described as "lymphocytic meningo-encephalitis with myalgia and rash," "An outbreak of a disease believed to have been cause by Echo 9 virus," with other varying descriptions.
1956 Pittsfield, Williamstown, Massachusetts, USA: Outbreak of "epidemic neuromyasthenia" later described as benign myalgic encephalomyelitis. Began after an ill serviceman returned home from England.
1956-7 Coventry, England: Outbreak described as epidemic malaise and benign myalgic encephalomyelitis.
1957 Brighton, South Australia: Outbreak described as "Coxsackie, Echo Virus meningitis and mylagic encephalomyelitis", "Epidemic myalgic encephalomyelitis," and "Benign myalgic encephalomyelitis."
1958 Athens, Greece: An outbreak of benign myalgic encephalomyelitis in a nurse's school.
1958-9 S.W. London, England: Reports of sporadic cases of myalgic encephalomyelitis.
1959 Newcastle upon Tyne, England: Outbreak of benign myalgic encephalomylitis.
1959 N.W. London, England: Reports of sporadic cases of influenza-like illness
1961 Basel, Switzerland: sporadic case of benign myalgic encephalomyelitis described.
1961-2 New York State, USA: Outbreak described as epidemic neuromyasthenia in a convent in New York State.
1964-6 N.W. London, England: Outbreak described as epidemic malaise and epidemic neuromyasthenia.
1964 Franklin, Kentucky, USA: Outbreak of "neuromyasthenia" in a Kentucky factory, possibly due to mercury exposure.
1965-6 Galveston County, Texas, USA: Outbreak described as "Epidemic Neuromyasthenia Variant?" and "Epidemic Diencephalomyelitis," the latter describing neuropsychiatric, cardiovascular and endocrine disorders.
1967-70 Edinburgh, Scotland: Sporadic cases resembling benign myalgic encephalomyelitis.
1968 Fraidek, Lebanon: Report on an epidemic of benign myalgic encephalomyelitis.
1969 State University of New York, USA: Medical Centre - report of epidemic Neuromyasthenia and "unidentified symptom complex."
1970 Lackland Air Force Base, Texas, USA: Epidemic Neuromyasthenia reported. "A syndrome or disease?"
1970-71 London, England: An outbreak of "epidemic neuromyasthenia" among nurses at the Hospital for Sick Children
1975 Sacramento, California, USA: "200 hospital staff in the [Mercy San Juan Hospital] fell ill in August - September 1975 The epidemic appears to have spread to the children of the hospital staff and from there to the children's teachers. 43 have been seriously disabled with chronic illness from 1975-1992"
1976 Southwest Ireland: Reports on Mylagic Encephalomyelits and epidemic neuromyasthenia in this region.
1977 Dallas-Fort Worth, Texas, USA: "Epidemic Neuromyasthenia" reported.
1979 Southampton, England: Outbreak of M.E. in a girls' school.
1980-81 West Kilbridge, Ayrshire, Scotland: M.E. epidemic reported in a rural medical practice.
1980-83 Helensburgh, Scotland: Coxsackie B outbreak reported in a general practice.
1981-82 Stirlingshire, Scotland: Sporadic cases of M.E. reported.
1982-84 West Otago, New Zealand: Outbreak first described and an "unexplained illness," later as M.E. Included here are outbreaks in Dunedin and Hamilton New Zealand.
1984 "From 1984 until 1992 an endemic period occurred in which an usually large number of cluster and epidemics of M.E./CFS have been recognized in North America. After an apparent initial increase in the morbidity in 1983 there seemed to have appeared in late summer of 1984 an unprecedented increase of sporadic and epidemic cases across North America. Although certain geographical hot spots seen to have taken up much of the medical interest, this endemic situation probably represents an unusual and unremitting morbidity in all areas of the United States and Canada." -Dr. Byron Hyde-
1984 Incline Village, Lake Tahoe, Nevada, USA: "A chronic illness characterized by fatigue, neurologic and immunologic disorders and active human herpesvirus type 6 infection." "This community epidemic, apparently started in a girls' basketball team, then involved primarily teacher in at least three high schools, and then large numbers of the community."
1984 Chapel Hill, North Carolina, USA: "Epidemic amongst members of The North Carolina Symphony Orchestra. Low NKC [Natural Killer Cells] associated with high yield of lymphoma, astrocytoma, glioma."
1984 Montreal, Quebec-Ontario, Canada: "Over 500 cases of M.E./CFS documented during August-November 1984 period.
1984-85 Truckee, California, USA: M.E. epidemic involving teachers and students.
1985 Lyndonville, New York, USA: M.E. epidemic in a rural community involving children and adults.
1985 Yerington, Nevada, USA: "In the same area [not far from Truckee, California] an M.E./CFS-like epidemic reputedly occurred in a reservation of American Native people."
1986 Placerville, California, USA: "Outbreak of chronic fatigue syndrome 'coincident with a heavy contamination of the local unfiltered water supply'."
1988 Sonora, California, USA: "More than 35 children and adults were diagnosed with M.E. in the mountain country 100 miles from Lake Tahoe. Many of these patients were associated in some way with Columbia Community College."
1989 Roseville, California, USA: Rosedale Hospital reported 11 cases of M.E./CFS among staff.
1990 Elk Grove, California, USA: M.E. epidemic among teachers and students.