Jane Colby, a former Essex headteacher who retired early after contracting ME, and Elizabeth Dowsett, honorary consultant microbiologist for Basildon and Thurrock NHS Trust, have discovered more than 100 reported cases in Essex, Humberside and Hertfordshire.
A total of 634 schools responded to a survey in the three counties, out of 1,902 contacted. Of these, 123 reported cases of ME among either staff or pupils.
The researchers, mainly sponsored by the Action for ME charity, say the figures suggest the incidence of ME among schoolchildren nationally could be up to 130 per l00,000 - three times the UK figure for multiple sclerosis. This suggests as many as 24,000 children nationwide may be ME sufferers, while the incidence among teachers may be as much as four times that of the general population.
The survey is likely to be met with some scepticism because ME is still not universally recognised as a medical disorder. According to Action for ME, 38 per cent of GPs still do not recognise it.
While it is acknowledged by both the Department of Health and the World Health Organisation - which defines it as "an organic disorder of the brain" - a group of 150 leading psychiatrists last month dismissed it, saying there was "no strong evidence of persistent viral infection in any but a small number of patients".
ME is thought to be caused by a virus related to polio, but is difficult to diagnose. Symptoms include fatigue, muscle pain, and inability to concentrate.
The survey identified 72 school staff with ME and of those, 27 took early retirement. The researchers say many sufferers have to retire early because schools do not allow them to teach a modified timetable.
Ms Colby said: "The survey results are pretty startling. We are finding that where there are clusters, there are also cases of school phobics, and stress and nervous debility problems, all conditions known to be misdiagnosed. "
Dr Alan Franklin, an ME specialist and paediatrician at St John's Hospital, Chelmsford, told The TES that many "school phobics" he saw were ME sufferers who wanted to go to school but could not cope.
The survey suggests that children aged 13 to 16 and older primary pupils are most likely to be hit by ME, and that teachers are most vulnerable between 30 and 50.
* A new Action for ME helpline has been launched, on 0891 122976.
ME Guidelines for Schools costs 75p from Action for ME, PO Box 1302, Wells BA5 2WE.