A sudden outbreak of illness suggestive of mass hysteria in schoolchildren
G. W. Small, D. T. Feinberg, D. Steinberg and M. T. Collins
Department of Psychiatry and Biobehavioral Sciences, School of Medicine, University of California-Los Angeles.
OBJECTIVE: To clarify factors contributing to mass illness of sudden onset
by studying an outbreak that was apparently triggered by a gaseous odor and
that involved a rapid, extensive response by school and fire officials.
SETTING: Urban elementary school. MAIN OUTCOME MEASURE: A standardized
student questionnaire was designed to identify potential illness
predictors. DESIGN: Four weeks following the outbreak, public health
officials distributed the questionnaire to all students in regular classes
in grades 3 through 6 (N = 319), representing 46% of the estimated 680
students present the day of the outbreak. RESULTS: Seventy-seven percent of
the students who completed the questionnaire reported that they experienced
physical symptoms during the epidemic. A stepwise regression analysis
demonstrated several independent variables that predicted the severity of
illness, including the intensity of the odor smelled during the outbreak (P
< .0001), becoming sick after the fire trucks arrived (P < .0001),
and believing in an environmental cause for the illness (P < .002).
CONCLUSIONS: These results indicate that both psychological and
environmental factors, real or perceived, may contribute to sudden-onset
epidemics of hysteria. Moreover, the response intervention of officials may
influence the extent of such outbreaks. Early recognition of psychological
causes and dispersion of groups at risk could reduce morbidity and
associated health care costs.
