List of myalgic encephalomyelitis and chronic fatigue syndrome outbreaks

There have been dozens of documented outbreaks of myalgic encephalomyelitis and chronic fatigue syndrome since the 1930s. The true number of clusters and outbreaks is likely vastly higher. Many of these outbreaks occurred in institutions like hospitals and schools, and frequently coincided with outbreaks of poliomyelitis.

The first recorded outbreak was in 1934 in Los Angeles and the most recent putative outbreak was in Arizona in 1996.

1934 - Los Angeles, US
Epidemic among personnel at L.A. County Hospital, Ruth Protection Home and throughout California, paralleling poliomyelitis, often diagnosed as atypical poliomyelitis, sometimes including arthropathy.

1936 - Fond-du-Lac, Wisconsin, US
An outbreak of "encephalitis" in St. Agnes Convent.

1937 - Erstfeld, Switzerland
In less than two weeks, 130 soldiers stationed in Erstfeld, Switzerland became ill with a disease that was attributed to "Abortive poliomyelitis."

1937 - St. Gallen, Switzerland
Outbreak in the women's section of a hospital in St Gallen, Switzerland affecting 28 staff and patients. They were diagnosed with "Abortive Poliomyelitis."

1939 - Middlesex, England
Outbreak at Harefield Sanatorium - "Persistent myalgia following sore throat."

1939 - Degersheim, St. Gallen, Switzerland
Seventy-three cases of epidemic neuromyasthenia were reported among 800 soldiers stationed in Degersheim, Switzerland.

1945 - University Hospital of Pennsylvania, US
Epidemic described as "pleurodynia with prominent neurological symptoms and no demonstrable cause."

1946-47 - Iceland
"Mixed epidemics of poliomyelitis and a disease resembling poliomyelitis with the character of the Akureyri Disease."

1948-49 - North Coast Towns, Iceland
"A disease epidemic in Iceland simulating Poliomyelitis" in three separate towns during this time.

1949-1953 - Adelaide, Australia
Outbreak of a disease resembling poliomyelitis, during/after a poliomyelitis epidemic.

1950 - Louisville, Kentucky, US
Outbreak in the Nurse's Training School of St. Joseph Infirmary, later described as "epidemic neuromyasthenia."

1950 - Upper New York State, US
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, US
Outbreak described as epidemic neuromyasthenia.

1953 - Coventry and Coventry District, England
"An illness resembling Poliomyelitis observed in nurses."

1953 - Rockville, Maryland, US
Chestnut Lodge Hospital student nurses described with poliomyelitis-like epidemic neuromyasthenia.

1953 - Jutland, Denmark
Outbreak of "Epidemic encephalitis with vertigo."

1954 - Tallahassee, Florida, US
Bond JO. A new clinical entity? Lancet 1956; 2:256.

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.

1954 - Dalston, Cumbria, England
"...an unusual disease seen in epidemic and sporadic form in general practice in 1955 and subsequent years."

1955 - Perth, 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.

1955-56 - Segbwema, Sierra Leone
An outbreak of encephalomyelitis.

1955-56 - Patreksfordur and Thorshofn, Iceland
Unusual response to poliomyelitis vaccination.

1955-1957 - Royal Free Hospital outbreak, London, England
Famous outbreak of benign myalgic encephalomyelitis simulating poliomyelitis, beginning among a residential home for nurses at the Royal Free Hospital.

1956 - Ridgefield, Connecticut, US
An epidemic of neuromyasthenia.

1956 - Punta Gorda, Florida, US
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, US
Outbreak of "epidemic neuromyasthenia" later described as benign myalgic encephalomyelitis. (Included in this summary are sporadic cases in Hygiea, Sweden, with descriptions of encephalitis, meningitis or poliomyelitis; Coxsackie B and Echovirus infections; benign myalgic encephalomyelitis.)

1956-57 - Coventry, England
Outbreak described as epidemic malaise and benign myalgic encephalomyelitis.

1957 - Brighton, South Australia
Outbreak described as "Coxsackie, Echo Virus meningitis and myalgic encephalomyelitis", "Epidemic myalgic encephalomyelitis," and "Benign myalgic encephalomyelitis."

1958 - Athens, Greece
An outbreak of benign myalgic encephalomyelitis in a nurse's school, "periostitis and arthropathy noted." (Included in this summary is an outbreak of benign myalgic encephalomyelitis in Switzerland.)

1958-59 - 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.

1959 - England
Article describing sporadic cases and "The psychiatric sequelae of Benign Myalgic Encephalomyelitis."

1961 - Basel, Switzerland
Sporadic case of benign myalgic encephalomyelitis described.

1961-62 - New York State, US
Outbreak described as epidemic neuromyasthenia in a convent in New York State.

1964-66 - N.W. London, England
Outbreak described as epidemic malaise and epidemic neuromyasthenia occurred in North Finchley, a suburb of London, England.

1964-66 - Franklin, Kentucky, US
Outbreak of "neuromyasthenia" in a Kentucky factory, possibly due to mercury exposure.

1965-66 - Galveston County, Texas, US
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 - Fnaidek, Lebanon
Report on an epidemic of benign myalgic encephalomyelitis.

1969 - State University of New York, US
Medical Centre - report of epidemic Neuromyasthenia and "unidentified symptom complex."

1970 - Lackland Air Force Base, Texas, US
Epidemic Neuromyasthenia reported. "A syndrome or disease?"

1970-71 - London, England
An outbreak of "epidemic neuromyasthenia" among nurses a the Hospital for Sick Children, Great Oromond Street.

1975 - Sacramento, California, US
In 1975, an epidemic started first among the ICU staff and later spread throughout Mercy San Juan Hospital, in Carmichael, a suburb of Sacramento, CA. An estimated 200 people became ill. Dr Ryll, who headed the investigating medical team, called it "Infectious Venulitis" which he later believed to be a variant of ME/CFS.

1976 - Southwest Ireland
Reports on Mylagic Encephalomyelits and epidemic neuromyasthenia in this region.

1977 - Dallas-Fort Worth, Texas, US
"Epidemic Neuromyasthenia" reported.

1979 - Southampton, England
Outbreak of M.E. in a girls' school.

1980s
1980-1988 Children’s hospital San Diego outbreak closes down Hospital. CDC investigates. Six children die 1980. Medical doctor and two intensive care nurses die.

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.

1981 - Gunnedah, NSW, Australia
The Gunnedah outbreak was linked with pesticides, which were conjectured to be interacting with viruses and other environmental chemicals in a post-viral syndrome. Those affected included one local GP, with that GP forming the view this was clearly a physical illness. The outbreak was featured in a film More than Just Poison made in 1986 by the Toxic and Hazardous Chemicals Committee.

1984 - Tapanui & 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 - North America (Endemic)
"From 1984 until 1992 [at publication of this text] an endemic period occurred in which an usually large number of cluster and epidemics of ME/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, US
A chronic illness characterized by fatigue, neurologic and immunologic disorders and active human Human herpesvirus 6 infection. This community epidemic apparently started in a girls' basketball team, then involved primarily teachers in at least three high schools, and then large numbers of the community.

Note: This outbreak prompted a Centers for Disease Control response and was the catalyst for the name Chronic fatigue syndrome and the development of the CDC's 1994 research diagnostic tool Fukuda criteria used worldwide.

1984 - Chapel Hill, North Carolina, US
"Epidemic amongst members of The North Carolina Symphony Orchestra. Low NKC Natural killer cells associated with high yield of lymphoma, astrocytoma, glioma."

All the members of the N.C. Symphony Orchestra, Chapel Hill, NC got sick. Seven remained ill with chronic fatigue as late as 2009. A series of studies done in 1988 and 1989 by the University of Pittsburgh Cancer Center showed that four of the inflicted NC orchestra members who developed cancer had lower levels of activity of natural killer cells, a type of immune cell that can directly kill cancer.

1984 - Montreal, Quebec-Ontario, Canada
Over 500 cases of M.E./CFS documented during August-November 1984 period. This endemic was active in all parts of Canada during this period and appears [to] have maintained its activity until the time of writing in 1991.

1984-85 - Truckee, California, US
M.E. epidemic involving teachers and students. 1984 - 1985: Incline Village Nevada Lake Tahoe outbreak in town and all people vacationing at This resort town.

1985 - Lyndonville, New York, US
M.E. epidemic in a rural community involving children and adults.

1985 Yerington, Nevada, US
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, US
Outbreak of chronic fatigue syndrome 'coincident with a heavy contamination of the local unfiltered water supply'.

1988 - Sonora, California, US
"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, US
Rosedale Hospital reported 11 cases of M.E./CFS among staff.

1990 - Elk Grove, California, US
M.E. epidemic among teachers and students.

1996 - Mohave Valley region, Arizona, US
Over 100 people became ill with a "multi-system stealth virus infection with encephalopathy (MSVIE)." A protracted course followed, with a diverse range of symptoms similar to CFS.

2003 Hong Kong outbreak
The 2003 Hong Kong outbreak of chronic fatigue syndrome was caused by the SARS pandemic.

2004 Bergen, Norway outbreak
An outbreak of Giardia, a parasite, in the water supply resulted in many people exposed to it developing either chronic fatigue syndrome or irritable bowel syndrome. A number of follow-up studies of this patient group have since been published.

2019-21 Coronavirus pandemic outbreak
The discovery of a new coronavirus and the related COVID-19 illness it caused led to a pandemic, with cases believed to have begun in November or December 2019.

2019-21 Coronavirus pandemic outbreak
The coronavirus first discovered in December 2019 led to high rates of COVID-19 illness, with COVID-19 being declared a pandemic in March 2020. The resulting Long COVID outbreak led to a ME/CFS outbreak, which remains ongoing. COVID-19 was a similar illness to SARS, which cause the 2003 Hong Kong outbreak of ME/CFS.

North America

 * 1984 - North America (Endemic)

Canada

 * 1984 - Montreal, Quebec-Ontario, Canada

United States

 * 1934 - Los Angeles, US
 * 1936 - Fond-du-Lac, Wisconsin, US
 * 1945 - University Hospital of Pennsylvania, US
 * 1950 - Louisville, Kentucky, US
 * 1950 - Upper New York State, US
 * 1952 - Lakeland, Florida, US
 * 1953 - Rockville, Maryland, US
 * 1954 - Tallahassee, Florida, US
 * 1954 - Seward, Alaska, US
 * 1956 - Ridgefield, Connecticut, US
 * 1956 - Punta Gorda, Florida, US
 * 1956 - Pittsfield, Williamstown, Massachusetts, US
 * 1961-62 - New York State, US
 * 1964-66 - Franklin, Kentucky, US
 * 1965-66 - Galveston County, Texas, US
 * 1969 - State University of New York, US
 * 1970 - Lackland Air Force Base, Texas, US
 * 1975 - Sacramento, California, US
 * 1977 - Dallas-Fort Worth, Texas, US
 * 1984 - Incline village, Lake Tahoe, Nevada, US
 * 1984 - Chapel Hill, North Carolina, US
 * 1984-85 - Truckee, California, US
 * 1985 - Lyndonville, New York, US
 * 1985 Yerington, Nevada, US
 * 1986 - Placerville, California, US
 * 1988 - Sonora, California, US
 * 1989 - Roseville, California, US
 * 1990 - Elk Grove, California, US
 * 1996 - Mohave Valley region, Arizona, US

Denmark

 * 1952 - Copenhagen, Denmark
 * 1953 - Jutland, Denmark

Germany

 * 1954 - Berlin, Germany

Greece

 * 1958 - Athens, Greece

Iceland

 * 1946-47 - Iceland
 * 1948-49 - North Coast Towns, Iceland
 * 1955-56 - Patreksfordur and Thorshofn, Iceland

Ireland

 * 1976 - Southwest Ireland

Norway

 * 2004 - Bergen outbreak

Switzerland

 * 1937 - Erstfeld, Switzerland
 * 1937 - St. Gallen, Switzerland
 * 1939 - Degersheim, St. Gallen, Switzerland
 * 1961 - Basel, Switzerland

United Kingdom

 * 1939 - Middlesex, England
 * 1952 - London, England
 * 1953 - Coventry and Coventry District, England
 * 1954 - Liverpool, England
 * 1954 - Dalston, Cumbria, England
 * 1955 - London, England
 * 1955 - Gilfach Goch, Wales
 * 1955-57 Royal Free Hospital, North West London, England
 * 1956 - Newton-le-Willows, Lancashire, England
 * 1956-57 - Coventry, England
 * 1958-59 - S.W. London, England
 * 1959 - Newcastle upon Tyne, England
 * 1959 - N.W. London, England
 * 1959 - England
 * 1964-66 - N.W. London, England
 * 1967-70 - Edinburgh, Scotland
 * 1970-71 - London, England
 * 1979 - Southampton, England
 * 1980-81 - West Kilbridge, Ayrshire, Scotland
 * 1980-83 - Helensburgh, Scotland
 * 1981-82 - Stirlingshire, Scotland

Lebanon

 * 1968 - Fraidek, Lebanon

Sierra Leone

 * 1955-56 - Segbwema, Sierra Leone

South Africa

 * 1955 - Durban and Durban City, South Africa

Australia

 * 1949-1953 - Adelaide, Australia
 * 1955 - Perth, Australia
 * 1957 - Brighton, South Australia
 * 1981 - Gunnedah, NSW, Australia
 * 1988 - Narrabeen, NSW, Australia

New Zealand

 * 1984 - West Otago, New Zealand

Related Lists

 * Myalgic Encephalomyelitis and Post Viral Fatigue States: the Saga of the Royal Free Disease by Dr Melvin Ramsay, 1955.
 * Reference index of papers published on epidemics of ME 1934-80 (collected by Dr J. Gordon Parish), ME Research UK, 1980.
 * The Clinical and Scientific Basis of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome (edited by Dr. Byron Hyde), Nightingale Foundation, 1992.