The thing is, that's about everything we know about the outbreak. The story would have made a great article for the New Yorker. Stretched out to 220 pages it is repetitive and full of background stuff that isn’t particularly relevant. So while it is an interesting book, it isn't a great one.
The one really interesting addition to the basic story is the last chapter, which is a survey of contagious, hysterical reactions in the anthropological and medical literature. The Strasbourg dancers were in some kind of trance or fugue state; contemporaries observed that while there were fakers, they were easily detected because they simply could not keep dancing as long or with as much intensity as the victims of the plague. And there have been other cases of such outbreaks, including a well-documented one on Madagascar in the 1860s. I was especially struck by the observation that the symptoms of hysterical or psychosomatic outbreaks have changed over time. In the 18th and 19th centuries, people used to dance uncontrollably, or at least jerk and foam, or go mute. Now the symptoms almost always imitate medical conditions. A lot of shellshocked soldiers in WW I developed . As the dominant model of severe medical crises shifted from curse or possession to disease, the symptoms of the deranged shifted with it:
Perhaps the most salient development in the modern history of hysteria has been a more general shift away from dramatic motor symptoms during the twentieth century. . . .Mutisms, convulsions, paralyses, altered states, and sensory deficits due to anxiety seem to be less common today than in any time over recorded history. This trend was perceptible even during the First World War, as military hospitals were deluged with men suffering from an almost certainly nervous condition dubbed “Disordered Action of the Heart” that involved , giddiness, and palpitations. During the Second World War, there were even fewer cases of the flamboyant hysterias of the Victorian era. Today, severe stress is far more likely to be express in a form psychiatrists call “somatoform disorder,” involving psychogenic pain (often headaches and stomach or bowel discomfort), fatigue, dizziness, or a general sense of malaise. Research in rural Indian provides strong evidence for this movement toward the less over somatoform disorder. In two well-studied Indian villages, rates of fell significantly between 1972 and 1987. Far more people now complain of pain and fatigue than motor paralysis or sensory loss. This shift has been attributed to a general increase in the mental health of women due to improved access to schools and, just as importantly, education having reduced “public credulity.”
As normal behavior changes, so does mental illness.