Extending Disease Surveillance with GIS
Continued...
Existing disease surveillance framework operates in formal, informal, and ad hoc settings, depending on the disease. Although disease surveillance in developing and industrialized countries focuses on both human and animal diseases, programs dedicated to a specific disease or group of diseases have had the greatest effect on the evolution of current global disease surveillance. Consequently global or regional surveillance programs tend to concentrate on controlling particular diseases.
However, these disease-specific surveillance initiatives may help improve global disease surveillance through system integration. Effective disease surveillance will require an integrated approach to surveillance so that all surveillance activities are consolidated into a coherent global health information system. GIS can provide the infrastructure for integration.
Strengthening Global Disease Surveillance
Initiatives for improving the current disease surveillance system include a commitment by the international community to reduce the burdens caused by diseases such as HIV/AIDS, malaria, and tuberculosis. The World Health Organization (WHO) and global public health organizations have launched initiatives that will strengthen global disease surveillance. The goal is to enhance global disease outbreak management; strengthen surveillance within developing countries; and improve surveillance coordination and cooperation at local, regional, and national levels.
These initiatives present complex challenges that require substantial efforts. Appropriate technology and improvements in public health information infrastructure will allow the extensive synthesis of health-related data and help health officials identify populations at risk so appropriate action can be initiated. With its ability to capture, store, manipulate, analyze, and share health-related data and relate it to location, GIS is a key part of these efforts.
Disease surveillance systems integrated at the local level will form the foundation for an international network of surveillance systems. Networking systems can effectively share disease surveillance information in the event of a disease outbreak. International networks are currently a prominent feature of disease-specific initiatives such as polio eradication and influenza control. WHO has created a system of collaboration centers that ensures developing countries can access support services and currently maintains a worldwide system of more than 270 of these centers.
Current global disease surveillance systems vary by disease of interest and do not correspond with the disease outbreaks currently anticipated. The capacity of these systems depends on the level of commitment to control individual diseases or groups of diseases. Integrating data in a national health information system involves analyzing and understanding existing local and national health systems in terms of data structure, disease reporting, and standardization of geographically related databases.
To accomplish this, each local health department or contributing agency should have GIS capability for creating data and distributing it over secured networks. GIS provides the infrastructure and serves as a common platform for multidisease surveillance activities. This GIS system will be geographically centric and use GIS software for data creation and dissemination that conform to national geographic standards. This strategy ensures that data can be shared automatically with cooperating agencies.
Integrating Data Across Multiple Sites
The disease surveillance system suggested here can integrate disease-reporting activities into the bioterrorism response system. This system uses manual key entry of disease data acquired from hospitals, physicians, and laboratories via fax, telephone, or Web page. This model provides several advantages. It provides several automatic activities: georeferencing of disease reports, outbreak alerts generated using business rules, and alert queues for investigation. This system provides integrated input to other systems for questionnaire development and data export to other national systems.
GIS System Specification for Disease Surveillance
A GIS-centric preparedness system requires that each facility assess its readiness to participate in the disease surveillance system. Key resources must be in place before assessing readiness: a written plan that sets forth technological standards and guidelines and hardware and software for participating in the wider system. The plan should address the following factors:
- Data Quality—The validity of disease surveillance depends on data quality. Error-prone systems and data based on inaccurate measurements can negatively affect detection.
- System Usefulness—A surveillance system, by allowing for early detecion of disease outbreaks, leads to effective intervention.
- Flexibility—The system should be able to change as needed, and changes should occur with minimal additional time, personnel, or other resources.
- System Acceptability—Participants and stakeholders should willingly contribute to data collection and analysis.
- Portability—Determine how well the system can be duplicated in another setting, which relates to adherence to geographic standards.
- System Stability—Resilience to system changes.
Disease surveillance systems should anticipate disease outbreaks by incorporating a geographically based incident tracking system. This tracking system is fed by a continuous stream of clinical data for human and animal populations that ignores geopolitical boundaries. Clinical data includes signs, symptoms, and diagnostic results. However, use of this data will require the development of statistical and epidemiological methods for protecting patient confidentiality.
Internet-based GIS technology provides an alternative to traditional methods of information acquisition and makes information instantly available across the globe. Health data stored in a central server can be accessed from terminals connected via an intranet or the Internet. A rules-based system establishes panic levels and aids in interpretation of data generated by the system.
Adopting data creation and replication standards means that data is collected in accordance with industry practices that standardize issues such as the frequency of data updates and restrictions on dissemination. Without a clear data creation and replication standard, the data is suspect. ArcGIS provides robust data creation and replication tools. The true test of data quality is its reliability—is the information generated from it accurate enough, for example, to use for routing an ambulance? Esri software has become the de facto data creation and replication standard for health and human service organizations.
Most community data sharing is situational and not systemic. Consequently, the available information to respond to a large community threat or response is currently limited. To change this situation, databases must conform to metadata, data security, and access and use standards. Without a common data dissemination technology, data sharing is difficult, expensive, and problematic. Agreeing on a data dissemination technology can provide the impetus for bringing together the community of data creators and users. This can result in the generation of valuable information that is accessible and actionable in real time.
With ArcCatalog, one of the applications in ArcGIS Desktop, users can manage spatial data holdings, design geodatabases, and manage metadata. ArcCatalog supports Federal Geographic Data Committee (FGDC) and ISO 19115 metadata standards using XML. With ArcIMS Metadata Services, users can create a central, online metadata repository for publishing and browsing metadata over the Internet.
As public health organizations begin the important work of linking interdepartmental databases, they must also integrate the work of many community-based organizations. One way to assure data sharing is to use standards already embedded in the software employed.
Esri's GIS software is used by all 50 state health departments in the United States and most agencies of the U.S. Department of Health and Human Services, U.S. Department of Veterans Affairs, and the U.S. Department of Defense. WHO and most of its regional offices also use Esri software. The Centers for Disease Control and Prevention recommends Esri's software for the visualization of data in its NEDSS and PHIN architectural framework guidance. Many hospitals, managed care, and pharmaceutical organizations also use Esri software.
Conclusion
Incorporating GIS in any disease surveillance system will enhance it and provide a comprehensive information system that is more efficient and less cumbersome. To bring disease surveillance systems to the next level, both local and international public health officials must take advantage of advances in information technology. Just as important, these systems must be managed by information specialists who are trained in the collection and dissemination of GIS-centric information.
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