Yeah, probably "epidemic hysteria" (https://en.wikipedia.org/wiki/Mass_psychogenic_illness https://en.wikipedia.org/wiki/Mass_psychogenic_illness) or something

Yeah, probably "epidemic hysteria" (https://en.wikipedia.org/wiki/Mass_psychogenic_illness https://en.wikipedia.org/wiki/Mass_psychogenic_illness) or something similar might be more accurate, but that's also "a disease" of sorts, just mental/psychological rather than biological.