摘要：Public health readiness has increased at all jurisdictional levels because of increased sensitivity to threats. Since 2001, with billions of dollars invested to bolster the public health system’s capacity, the public expects that public health will identify the etiology of and respond to events more rapidly. However, when etiologies are unknown at the onset of the investigation but interventions must be implemented, public health practitioners must benefit from past investigations’ lessons to strengthen preparedness for emerging threats. We have identified such potentially actionable lessons learned from historically important public health events that occurred primarily as syndromes for which the etiological agent initially was unknown. Ongoing analysis of investigations can advance our capability to recognize and investigate syndromes and other problems and implement the most appropriate interventions. OVER THE PAST DECADE, PUB lic health vigilance and readiness have increased at the international, national, state, and local levels because of increased sensitivity to both naturally occurring and intentional emerging threats, the former including problems such as the 2009 influenza A (H1N1) virus pandemic and the latter including severe illnesses resulting from the deliberate introduction of biological and chemical agents. 1–5 Only 18 months following the intentional anthrax attack of 2001, the world was confronted by the natural emergence of severe acute respiratory syndrome (SARS), a paradigm for newly recognized syndromes for which the specific etiological agents initially are unknown. 6–9 However, unlike the case for SARS, for which well-coordinated global efforts resulted in rapid identification of the causative agent, there are and will continue to be infectious and other disease problems with causative agents that remain undiagnosed or with pathophysiology that remains unknown despite intensive investigative efforts. 10–12 Since the anthrax attacks of 2001, the expectations placed on the public health community by the public, the media, and elected officials have steadily increased. Billions of dollars have been invested to bolster the capacity, capability, and proficiency of the public health workforce and other public health system components. 13,14 The public’s expectation is that given this large investment in public health preparedness and response in recent years, “public health” will respond to and identify the infectious or noninfectious etiology of events more rapidly than in the past. However, precisely when the etiologies are unknown at the onset of public health investigation and response, but control and intervention measures must be implemented to protect the public’s health, public health and medical practitioners must mine lessons from past public health investigations to strengthen preparedness for emerging threats. We have identified such potentially actionable lessons that can help inform approaches to identify and control newly emergent infectious and noninfectious threats more rapidly. We focus on those events that occurred primarily as syndromes for which the etiological agent was unknown at the time of recognition and initiation of investigation. For some of these, the etiology remains unknown. Some of those events came to the attention of the Centers for Disease Control and Prevention (CDC) and the broader public health arena as emerging threats (e.g., SARS) or were brought to light by astute clinicians who recognized a potential problem and reported it to the public health authorities (e.g., immune-mediated polyradiculoneuropathy). For others (e.g., Guillain-Barré syndrome and Reye’s syndrome), the response emphasizes the importance of surveillance for recognizing unanticipated problems and bringing them in focus for investigations (L. Schonberger, MD, personal communication, December 8, 2009). We also indicate how, for some problems, public health professionals need to initiate a rapid, comprehensive investigation that may include selecting and implementing control measures even if the etiology remains unknown.
