March 1, 2002 -- In a scenario straight out of Hollywood, school children start vomiting and fainting, the school is evacuated, and health officials, media, and parents rush to the scene. No cause for symptoms is found and the event is labeled as mass hysteria.
Whether or not a perceived health threat is real, mass or epidemic hysteria -- alias mass sociogenic illness or mass psychogenic illness -- is a very real phenomenon that "may have profound public health, social, and economic repercussions," report health officials from the Tennessee Department of Health and the CDC in the Jan. 13, 2000, issue of The New England Journal of Medicine.
"For the safety of the community, I think you're obligated to do the best investigation you can regardless of what your suspicions are, and it's often only in retrospect that you can really be confident of the diagnosis," Timothy F. Jones, MD, an epidemiologist for the state of Tennessee, tells WebMD.
Jones was with the CDC's Epidemic Intelligence Service in 1998 when he and co-workers were called in to investigate an incident that occurred in a Tennessee high school. It began when a teacher complained of headache, nausea, shortness of breath, and dizziness after she detected a 'gasoline-like smell' in her classroom.
The school was evacuated, the teacher and several of her students were transported to the local emergency room, and eventually 80 students and 19 staff members went to the hospital, with 38 being admitted. When the school was reopened 5 days later, an additional 71 people went to the emergency room. Yet despite an extensive investigation and exhaustive medical and environmental testing, the investigators found no evidence of toxic compounds anywhere in the school.
The total bill for the incident -- including hospital and physician charges and environmental testing -- was in the range of $110,000. And that's not counting the estimated loss of more than 18,000 person days, or the cost to the community in terms of lost faith in the health and safety of their public facilities.
The story has been repeated time and again: In Belgium in 1999, there was a widespread scare about 'contaminated' Coca-Cola, causing public anxiety about food safety. In Los Angeles, and in Snohomish County, Wash., in 1994, it was noxious odors, causing school closings and public outcry about environmental safety. And in Salem, Mass., in 1692, it was fits and terrors among a group of young girls, sparking fears of witchcraft and causing the deaths by hanging or suffocation of 20 people and a dog.
The Tennessee incident bore all the hallmarks of mass psychogenic illness as defined by the CDC: unexplained illness that occurs in a 'line-of-sight' pattern (moving from one person to a nearby witness and on down the line), lack of illness in others sharing the same environment, symptoms such as dizziness and stomach distress, and a preponderance of cases among girls and women.
Alan Hedge, MD, PhD, a psychologist and professor of design and environmental analysis in the College of Human Ecology at Cornell University in Ithaca, N.Y., tells WebMD that even in the absence of identifiable causes -- such as the presence of a toxic compound or species of airborne bacteria such as the one discovered in 1976 that causes the illness now known as Legionnaire's disease -- the incident must be addressed promptly and forthrightly by all concerned.
"I think that the psychological side of managing building problems is really pretty neglected, and it's quite possible for people to become aversely conditioned to being in a building, just as you can be aversely conditioned to eating pizza if you think it's made you ill in the past. The view that you will only get a reaction to a real physical agent is, I think, an erroneous view. In many instances there's also a very strong psychological component to the reactions that people have."
Getting things back to normal as quickly as possible should be the goal of all responsible parties, Jones and his fellow researchers emphasize.
"Alleviation of the widespread anxiety surrounding an episode of mass psychogenic illness requires prompt recognition and a coordinated multiagency investigation," they write. "As fears about bioterrorism increase, the frequency of such incidents and the anxiety they generate may increase. Awareness of the characteristics of mass psychogenic illness is critical for physicians and other health care personnel who respond to such outbreaks."
- Mass psychogenic illness can have serious public health repercussions and often and can only be identified in retrospect.
- Signs of mass psychogenic illness are unexplained illnesses that occurs in a 'line-of-sight' pattern, lack of illness in others who share the same environment, and symptoms such as dizziness or stomach distress.
- Even in the absence of identifiable causes, each suspected incident should be addressed promptly and thoroughly in an attempt to return things to normal as soon as possible.