As part of an International Society for Disease Surveillance (ISDS) project to support member-initiated consultations on priority unresolved questions in the field of syndromic surveillance research, development, or practice, the Duval County Health Department obtained ISDS support to address the use of syndromic surveillance data, in combination with other human health and veterinary surveillance data, environmental sampling data, and plume modeling results, in the event of an airborne bioterrorist attack. The Duval County Health Department convened several state and local Florida public health officials to address this topic in the context of a hypothetical bioterrorist attack scenario in Duval County. The objective of this consultation was to develop expert, consensus-based recommendations for use of syndromic surveillance in combination with other data sources to improve situational awareness in the event of a large-scale public health emergency. While the practice of establishing or adapting surveillance systems to support outbreak management is well established, the discussions highlighted the absence of criteria for assessing the utility of various surveillance systems for situational awareness during a public health crisis. The breadth of data sources considered in this consultation—traditional and newer syndromic approaches to human health surveillance, environmental and atmospheric information combined into plume models, and multiple sources of animal health data—point to the potential utility of integrating widely different streams of information and to the challenges in assuring that the mix of data can be used effectively in a crisis.

For syndromic and related public health surveillance systems to be effective, health departments need access to a variety of types of health data. Since the development and implementation of syndromic surveillance systems in recent years, health departments' experience in gaining access to personal health information for syndromic surveillance has been mixed. Although the HIPAA Privacy Rule permits health care providers to disclose protected health information without patients' consent to public health agencies for authorized purposes, some health care providers have cited HIPAA in refusing to provide data for syndromic surveillance. Beyond HIPAA, a variety of federal, state, and local public health laws enable, restrict, and otherwise influence the sharing of health information between health care providers and public health agencies for surveillance, as well as research, purposes. To address these issues in the context of syndromic surveillance practice, an expert meeting was convened to (a) share experiences regarding privacy, confidentiality, and other legal and ethical issues; (b) clarify how these legal and ethical issues enable or constrain data sharing; and (c) identify approaches to protect privacy and confidentiality.

Rooted in the principle that state and local governments have inherent and broad powers to protect the health, safety and welfare of the people, public health agencies have the authority to collect personal health information, including the power to compel disclosure of such data under certain conditions. The precise limits of these public health powers have never been defined, however, and are limited by and must be balanced with the right of privacy. Although existing laws and regulations provide little clarity on how to balance disclosure risks and potential benefits of public health actions that reasonably follow from surveillance, guidance can be found in the principles known as the "Fair Information Practices." Two specific fair information practices—specification of purpose and limitation on secondary use—are especially critical for syndromic surveillance.

Considering these principles should help health officials to determine what level of health information detail, and thus what level of potential ability to identify individuals, is needed for the intended public health purpose, and whether surveillance will lead to effective public health action. The principles also suggest a number of strategies for dealing with concerns that the public or health care providers may have about sharing data with public health agencies: (a) improve communication with the public about how data are used to safeguard the population's health and how confidentiality is protected; (b) further develop approaches to sharing data in aggregate or de-identified form that have capability to link back to identified data when necessary; (c) further develop statistical approaches to anonymization and aggregation; and (d) conduct evaluation research and case studies that demonstrate utility and clarify how privacy and confidentiality are protected.

The objectives of this consultation, supported by the International Society for Disease Surveillance (ISDS), were to develop expert, consensus-based recommendations to promote Canadian and U.S. collaboration in using syndromic surveillance (SS) to detect, assess, monitor, or respond to potential or actual public health threats. The consultation focused on the Great Lakes region of the Canadian-U.S. border—a region where there is substantial flow of people and goods between the two nations, a potential for occurrence of public health emergencies that affect people in both countries. Despite prior advances achieved by participants in the Early Warning Infectious Disease Surveillance (EWIDS) program regarding cross-border collaboration in notifiable disease reporting and follow-up, the EWIDS deliberations had not substantially addressed the role and uses of syndromic surveillance as part of cross-border disease prevention and control efforts, particularly in the context of potential large-scale public health emergencies. Presentations addressed a mix of issues that define the context for cross- border collaboration, including updates on SS practice and development in jurisdictions in the region, shared methodological challenges, protocols for responding to SS alerts, health information privacy regulations, and policies concerning public health emergencies that may shape information sharing during a crisis. Potential legal barriers to information sharing centered on individual-level privacy concerns, as opposed to sharing of aggregate SS data or notices of statistical alerts based on SS data. The meeting provided an impetus and agenda for future, ongoing consideration of including syndromic surveillance as a key component within the broader context of the EWIDS process. Identified priorities included development of procedures to share information about SS alerts and alert response protocols within EWIDS, increased use of SS inputs in crossborder tabletop exercises for pandemic influenza, and further collaboration in development of mapping projects that use data inputs from both sides of the border. In addition, the participants recommended that annual ISDS conferences provide a forum to address challenges in cross-border collaboration in SS practice and research.