On the origin of mass casualty incidents in Kosovo, Yugoslavia, in 1990.

In March 1990, a mysterious outbreak of illness spread suddenly among thousands of ethnic Albanian high school students in Kosovo (Yugoslavia). It was an unprecedented event on the worldwide scale both in terms of the number of cases and in terms of controversies concerning the aetiology. A retrospective analysis indicated that the epidemic consisted mainly of cases who felt ill in the absence of exposure to any physical agent. It is suggested that in an atmosphere of severe tension between the two ethnic groups living in Kosovo an increased frequency of respiratory infections may have triggered mass sociogenic illness.