Only two months ago, many Americans were gripped by fear of the uncontrollable spread of an apparently incurable disease that the Centers for Disease Control and Prevention projected could strike 1.4 million people in West Africa before it came under control.
Amid such reports, it took only one case to touch off near-panic inside the United States: that of Liberian Thomas Eric Duncan after he was misdiagnosed by a Dallas hospital.
In the weeks that followed Duncan's death, state and local governments reacted — and sometimes overreacted. Several schools barred teachers and children who had visited African countries that were nowhere near the epidemic. In...