Comprehensive effective and efficient global public health surveillance

At a crossroads, global public health surveillance exists in a fragmented state. Slow to detect, register, confirm, and analyze cases of public health significance, provide feedback, and communicate timely and useful information to stakeholders, global surveillance is neither maximally effective nor optimally efficient. Stakeholders lack a globa surveillance consensus policy and strategy; officials face inadequate training and scarce resources. Three movements now set the stage for transformation of surveillance: 1) adoption by Member States of the World Health Organization (WHO) of the revised International Health Regulations (IHR[2005]); 2) maturation of information sciences and the penetration of information technologies to distal parts of the globe; and 3) consensus that the security and public health communities have overlapping interests and a mutual benefit in supporting public health functions. For these to enhance surveillance competencies, eight prerequisites should be in place: politics, policies, priorities, perspectives, procedures, practices, preparation, and payers. To achieve comprehensive, global surveillance, disparities in technical, logistic, governance, and financial capacities must be addressed. Challenges to closing these gaps include the lack of trust and transparency; perceived benefit at various levels; global governance to address data power and control; and specified financial support from globa partners. We propose an end-state perspective for comprehensive, effective and efficient global, multiple-hazard public health surveillance and describe a way forward to achieve it. This end-state is universal, global access to interoperable public health information when it’s needed, where it’s needed. This vision mitigates the tension between two fundamental human rights: first, the right to privacy, confidentiality, and security of personal health information combined with the right of sovereign, national entities to the ownership and stewardship of public health information; and second, the right of individuals to access real-time public health information that might impact their lives. The vision can be accomplished through an interoperable, global public health grid. Adopting guiding principles, the global community should circumscribe the overlapping interest, shared vision, and mutual benefit between the security and public health communities and define the boundaries. A global forum needs to be established to guide the consensus governance required for public health information sharing in the 21st century.

completeness), many more resources and focused eff ort is required to fulfi ll this dream that eludes even some of the more advanced and wealthy countries.
New movements have now come to the fore to expedite tomorrow's digital, paperless public health surveillance workplace and promote comprehensive surveillance. Th ere is strategic merit in conceiving a vision of the end state for comprehensive, global, multiple-hazard public health surveillance; one that acknowledges the challenges and identifi es steps to overcome them. We propose here a perspective for comprehensive, eff ective and effi cient global, multiple-hazard public health surveillance and describe a way forward to achieve it.

Global movements
Th ree important movements now set the stage to achieve comprehensive, eff ective and effi cient global, multiplehazard public health surveillance: 1. Th e adoption of the revised International Health Regulations [IHR(2005)] by all World Health Organiza tion (WHO) Member States, which includes national obligations to achieve a set of core surveillance and response capacities to prevent the international spread of disease [6]; 2. Th e maturation of information sciences (e.g., public health informatics [PHI]) capabilities and the remarkable penetration of information technologies (IT) to the most distant parts of the globe [7]; and 3. A consensus that both the security and public health communities have overlapping interests and mutual benefi ts to collaborate in supporting the development of essential public health functions, especially public health surveillance [8]. Th ese movements off er the practical opportunity to empower, enhance, and enjoin global public health surveillance, as never before.

Movement 1 -Adoption of IHR(2005)
Th e IHR(2005) constitutes the WHO's legal and operational framework for activities around prevention and control of the international spread of disease, regardless of origin or intent (e.g., chemical and radio-nuclear sources, as well as biological). Th e adoption of IHR(2005) by WHO Member States challenges them in a new and urgent way to assess and strengthen core surveillance capacities [9]. Th is agreement also provides the policy context to uniformly assess these capacities [10].

Movement 2 -The rise of public health informatics (PHI)
Information sciences and IT both used in a public health setting (i.e., public health informatics) are a means to an end; the end being the achievement of eff ective and effi cient public health surveillance. Concerned with eff ective and effi cient collection, collation, transmission, analyses, visualization, storage, and retrieval of electronic data, the scientifi c discipline of PHI has emerged to leverage the inherent merits found in IT and computer science technology. But this merger yields more than the sum of its individual parts-it has the potential to enhance the transformation to a 21 st century global public health surveillance digital (paperless) workplace. By identifying and defi ning standards and making them easier to apply, PHI adds value to eff orts already performed by public health practitioners at all health levels. Th is added value derives from the inherent ability of PHI to facilitate digital communication in a more robust, effi cient, and standards-based manner.
Over the past ten years, many public health processes have been improved by PHI solutions [11]. Th ese improved processes include the increased quantity and timeliness of mandatory case reporting; decreased dataentry burden on public health programs; provision of tools needed for emergency preparedness (e.g., rapid awareness of new cases, linkages to automatic alerting systems for public health personnel); and management support necessary during outbreak situations [12].
PHI also off ers paper-to-digital conversion techniques and tools that empower and enable epidemiologists and surveillance practitioners to work better, faster, and cheaper [13] by providing health information, including any information about individuals demonstrated to be related to health (e.g., medical records, laboratory reports, behavioral risk factors, medical examiner and vital records, school records) that is more complete, specifi c, and timely [14][15][16].

Movement 3 -Alignment of security and public health
Th e third movement aligns the overlapping, mutual interests of the security and public health communities around the domain of public health surveillance. It forces policy discussion, increases focus, as well as provides sources to drive progress. Th e WHO's 2007 World Health Report, "A safer future: global public health in the 21 st century", addresses the interface of health and security [17]. Th e following points are noted in the foreword: "Given today's universal vulnerability to [internationally signifi cant health and security] threats, better security calls for global solidarity… as the determinant and consequences of health emergencies have become broader, so has the range of players with a stake in the security agenda … successful implementation of the IHR(2005) serves the interests of politicians and business leaders as well as the health, trade and tourism sectors. " Additionally, World Health Assembly Resolutions 54.14 and 55.16, respectively, requested the WHO to "provide technical support to Member States for developing intervention programmes that prevent epidemics and respond to communicable disease threats and emer gen cies, particularly with regard to epidemiologic investiga tions, laboratory diagnoses and community and clinical management of cases" and "to continue, in consultation with relevant intergovernmental agencies and other inter national organizations, to strengthen global surveil lance of infectious diseases, water quality, and food safety, and related activities such as the revision of the International Health Regulations and development of WHO's food safety strategy, by coordinating information gathering on potential health risks and disease outbreaks, data verifi cation, analysis and dissemination, by providing support to laboratory networks, and by making a strong contribution to any international humanitarian response, as required. " [18,19].
Th e WHO plays a role in the international response to accidental or deliberate use of biological and chemical agents or radio-nuclear materials that aff ect health. Th ey have a vision for international public health security, ready to respond collectively to the threat of epidemics and other public health emergencies, both natural and man-made. Correspondingly, WHO has adopted mechanisms for supporting countries and stren gthen ing the international response [10].
Among global public health stakeholders there now seems to exist both the political will and an acknowledged, if yet undefi ned, overlapping interest and mutual benefi t to achieving comprehensive, eff ective and efficient global, multiple-hazard public health surveil lance. Th ere are areas where security and public health interests are seen to be at odds. However, some countries may not wish to share public health information with other countries that may be used for the security or economic advantage of the other nation. Th ese perceptions have been a challenge to global public health surveillance in recent years and may be considered a key challenge going forward.

Eight keys to comprehensive health protection
In order for these three movements to empower and enhance surveillance competencies and lead to the endstate perspective described here, eight prerequisites or conditions should be in place ( Figure 1). Th ey include politics, policies, priorities, perspectives, procedures, practices, preparation, and payers (Table 1). While these eight prerequisites have a loosely sequential nature, there are relationships and interdependencies among them that should be acknowledged because of critical linkages to core competencies of public health surveillance and action ( Figure 2).
Many challenges (gaps and impediments) exist between the current and end-state described here. Th ey can be disaggregated into technical, logistic, governance, and fi nancial domains. Within the technical domain, single (silo) categorical, disease-specifi c surveillance systems create the situation where public health practitioners cannot determine relationships between health conditions or co-morbidities (e.g., through data linkages). For example, new tuberculosis (TB) cases could be missed because HIV/AIDS data are not cross-matched with the TB registry. In this situation, surveillance becomes ineff ective, because it is incomplete; events that represent a public health threat or that could inform about a potential public health threat are missed. Many times disease-specifi c silos are created and sustained by single funding streams and corresponding program obligations and priorities. Th ey are often then maintained by program corporate cultures. Secondly, appropriate public health information is often not collected because what needs to be measured is often not known [20,21]. In these circumstances, surveillance systems are not fl exible enough to respond to new or unusual presentations of disease, events, or conditions (i.e., not easily adapted to changing information needs). Th irdly, current surveillance systems are often not timely (i.e., by the time an event of interest or concern is detected, the opportunity to intervene has passed) [22]. Additionally, some new surveillance systems are neither eff ective, nor effi cient (i.e, the delivery of needed information is dependent on an inordinate number of resources) [23]. Th e logistic gaps include technical disparities among Member States, such as the cost for internet access and IT infrastructure. Gaps also exist in surveillance practices (e.g., lacking legal or other administrative requirements for mandatory reporting).
Th ere is a critical gap in global governance, under which all Member States would agree to function. Countries now collect and communicate public health information within and outside their natural border. Th e amount and type of information and willingness to collaborate varies from region to region. While there is a justifi able need to share important public health information that might impact neighboring states (and the IHR[2005] provides the legal and technical framework for public health emergencies of international concern), there still exists some uncertainty about what types of public health information are appropriate, how they should be communicated, and how quickly they should be shared.
Challenges (or impediments) to bridge the gaps include both the lack of trust and perceived benefi t at various levels, the lack of a global governance model to address power and control of public health information, and the lack of focused fi nancial support from global partners.

End-state perspective for global public health surveillance
Enhancing global public health surveillance in the 21 st century involves empowering and enabling existing public health surveil lance systems to interoperate (i.e., one information system to communicate with another syntactically -mean ing two or more systems are capable of communi cat ing and exchanging data by using specifi ed data formats and communication protocols; and semantically -meaning the ability of computer systems to communicate information and have that information properly interpreted by the receiving system in the same sense as intended by the transmitting system). Surveillance systems should also be enjoined (or integrated -meaning streamlining data collection among systems to reduce redundancy of the data collected where it makes sense to do so). Th ese activities will lead to universal global access to interoperable public health information when it's needed, where it's needed. In the process sense, interoperable and integrated public health information means achieving eff ective and effi cient public health business practices and workfl ow empowered and enabled to be better, faster, and cheaper by IT. Operationally, comprehensive, global public health surveil lance means one sign-on access to authorized and necessary public health information. Public health information includes other information -when combined with health-related information -that provides a picture of population or community health. Consumers should have one-stop shopping for public health information; and there should be one source for integration of public health information for all users. Th is also means one common set of standards for "bringing together" or interoperating existing or new data streams. Most importantly, one size does not fi t all.
Demographic, clinical, laboratory and other information about patients with diseases of public health signifi cance should only have to be entered once, saving time and resources. Th e local, district, national, or inter national health authorities should be able to access real-time health outcome data and perform analyses or take timely and appropriate public health action based on that information. It should be stressed that keeping electronic health information private, confi dential, and secure while automatically and immediately electronically communi cating public health information to local public health authorities to satisfy mandatory public health reporting purposes is critical. Diff erent reporting systems may be in existence depending on the types of data and information being reported, purpose and urgency of relaying the information, and where the data/information is being reported.
Th is perspective embraces and mitigates the tension between two fundamental human rights. Th e fi rst is the human right to privacy, confi dentiality, and security of personal health information. Th is includes any infor mation about individuals demonstrated to be related to health (e.g., medical records, laboratory reports, behavioral risk factors, medical examiner and vital records, school records) and the right of sovereign, national entities to the ownership and authority over their citizens' public health information. Th e second is the human right of individuals to have real-time access to public health information that might impact their lives.
Data management requires much more than investment in technology; it involves how data are created, stored, moved, used, and retired. As opposed to the 20 th century replicated database model, a federated model of public health information sharing allows multiple participants to share data without having to give up ownership, thus accommodating universal access to public health information [24]. A federated model is a type of metadatabase management system that transparently integrates multiple autonomous database systems into a single one. Th e constituent databases are interconnected via a computer network, and may be geographically decen tralized. Since the constituent database systems remain autonomous, a federated database (or virtual database) is the fully-integrated, logical composite of all constituent databases.
One mechanism to achieve this federated model is through a global public health grid (http://cdc.confex. com/cdc/phin2009/webprogram/Paper21091.html) (Figure 3). Th e goal of the grid is to improve population health by facilitating timely and reliable global public health information exchange. Th e global grid has the core principles of long-term sustainability; low barrier to entry (technically, fi nancially and socially); and uses a standards-based approach that is reusable, collaborative, and open source.

Recommendations
Th e way forward that addresses the gaps and challenges to achieve the end-state paradigm described here for comprehensive, eff ective and effi cient, multiple-hazard global public health surveillance lies through incor poration of these key principles: 1. People are key and listening is important -true partnership takes this into account. 2. Transparency builds trust and is crucial to success. 3. Mutual respect and mutual benefi t are vital and necessary. Th is includes a full recognition of data owner ship, national sovereignty, and the rights of individual patients. 4. Competence, relevance, and a common language in public health practice are required. 5. A culture of responsible stewardship and quality data is mandatory. 6. While one-size-does-not-fi t-all, a set of core capacities does exist [25]. Each Member State should proactively assess its own public health surveillance performance to identify and address gaps. Adopting these guiding principles, the global community should carefully circumscribe the overlapping interest, shared vision, and mutual benefi t of the security and public health communities within the domain of public health surveillance and defi ne the boundaries of those mutual interests. Finally, a global forum should be established to guide consensus governance required for public health information sharing in the 21 st century. Once the impediments of power and control of data are recognized, respected, and addressed, universal access to public health information can occur.
Abbreviations IHR, International Health Regulations; IT, Information technology; PHI, Public Health Informatics; TB, Tuberculosis; WHO, World Health Organization.

Competing interests
We confi rm that we do not have any confl icts of interest. Drs. McNabb and Chungong have no fi nancial or personal relationships that inappropriately infl uence (bias) their actions (such relationships are also known as dual commitments, competing interests, or competing loyalties). Neither of us have fi nancial relationships (such as employment, consultancies, stock ownership, honoraria, and paid expert testimony) likely to undermine our credibility. We have no confl icts for other reasons, such as personal relationships, academic competition, and intellectual passion.