1970 London outbreak

1970 London outbreak: In 1970-1971, at least 145 cases of epidemic neuromyasthenia (ENM) were observed in the staff of the Hospital for Sick Children, Great Ormond Street, London, England. The majority of those affected were nurses.

The outbreak occurred in two waves. The first wave, between mid-August and the end of September 1970, had thirty-three cases. Most were student nurses with one case being a nun who taught the students. The second wave ended towards the end of January 1971 and affected all levels of hospital staff, including administrative and domestic staff. A few sporadic cases developed between February and June 1971.

The breakdown of who became ill was: 103 student nurses, 21 senior nurses, 6 doctors and 15 hospital staff. The vast majority were female, but four males (two doctors and two administrators), also, became ill. No patients were affected.

Symptomatology included headache, sore throat, nausea, vomiting, diarrhea, dizziness, faintness, depression, muscle and joint pain, paresthesia, photophobia, malaise and fatigue. A striking symptom reported was rapid fatigability with exercise and relapses over a prolonged period sometimes lasting several years. Duration of the illness varied greatly and was hard to determine because of relapses. Even those who recovered from the illness never fully regained their pre-illness level of health.

Laboratory and other testing was unable to uncover an infectious agent, although the pattern of the outbreak pointed to an infective etiology.