Outbreak of mass hysteria during ethics training in one secondary school, Muang district, Ubon Ratchathani , June 2017

Abstract

Introduction: This report presents an outbreak investigation of mass hysteria during ethics training in one secondary school, Muang district, Ubon Ratchathani province, June 2017. The objectives were to verify diagnosis and outbreak, describe epidemiologic characteristics by person, place and time, determine factors and stimuli associated with this outbreak, and recommend preventive and control measures.
Methods: The investigation included reviewing medical records of the patients with diagnosis of mass hysteria during the outbreak, active case finding in the school, Unmatched case-control study to determine factors associated with this outbreak, environmental survey in the school, a qualitative study by group interview, and mental health assessment by the Mental Health Crisis Assessment and Treatment Team (MCATT) of Ubon Ratchathani province.
Results: Of the 375 secondary school students attending the ethics training during 9-11 June 2017, 30 (8.0%) developed mass hysteria. None died in this outbreak. The most common feature was carpopedal spasm (70.0%), followed by dyspnea (53.3%), and paresthesia (46.7%). The first case had onset of illness about 7.10 pm, 10 June 2017. The second case developed symptoms 5 minutes after the first and 28 cases subsequently developed symptoms within 30 minutes later. The attack rate of illness among girls (13.9%) was significantly higher than boys (1.1%). Students in the senior secondary school level (10.4%) had a higher (but not statistically significant) rate than those in the junior level (6.8%). Both case-control study and multiple logistic regression analysis revealed that factors significantly associated with illness were being girls, having a family member with a chronic disease and having no appreciation of a lecturer. Most students lived in poor family frequently having family problems. Their environment, culture and belief were related to religious ceremony, spirit and superstition.
Conclusion: An outbreak of mass hysteria involving 30 students occurred during the ethics training in one secondary school, Muang district, Ubon Ratchathani province, June 2017. Factors significantly associated with illness were being girls, having a family member with a chronic disease and having no appreciation of a lecturer. These factors should be paid attention to prevent and manage the outbreak of mass hysteria.