Overall, our findings suggest that there is overwhelming support for Annex 2 among NFPs. Although States Parties appear to have varied capacities in event-based surveillance, we found that the vast majority of NFPs had a strong awareness and knowledge of Annex 2, particularly those within government health agencies. Annex 2 was deemed useful for assessing communicable diseases, and less helpful for discerning other types of potential PHEICs. NFPs cited numerous initiatives to support the practical use of the tool and provided several suggestions on how to improve its user-friendliness.
Our results indicate that States Parties' ability to detect potential PHEICs was strongest in government health agencies, and lowest in agencies of national security, transportation and energy. Results from this study suggest that many States Parties may be struggling to establish core capacities in event-based surveillance . The IHR (2005) calls upon State Parties to enhance their surveillance and response infrastructure and necessary logistical and human resource capacity across all governments sectors by 2012 . However, for many low resource countries, the development of an epidemic intelligence framework across multiple sectors, as has been done in the European Union for example , poses a serious financial challenge  and may explain the significant variation between States Parties' reported surveillance capacity [16–19]. These findings suggest there is scope for the WHO to further support States Parties in enhancing their national surveillance, potentially by leveraging existing bilateral partnerships focused on capacity building .
We also found that the majority of NFPs regularly used Annex 2 for the assessment of public health events, and had taken active steps towards institutionalizing its use in their national, regional and municipal surveillance systems. The majority of NFPs had facilitated trainings about Annex 2 in their country, many had developed general SOPs and systems to facilitate rapid communication of public health events from municipal to national levels of government. Of note, the vast majority of States Parties had some form of legal, regulatory or administrative provisions supporting the use of Annex 2 and many had guidelines to facilitate its interpretation. These findings suggest that most States Parties are meeting their IHR core capacity requirements for the establishment of national legislation and policy , and that many federations, where public health regulatory power resides in local or regional governments, may be centralizing and harmonizing their public health policies and practices, allowing them to better comply with the IHR(2005) [21–23]. The fact that most States Parties indicated they had legislation specific to the four diseases requiring automatic under the IHRs Annex 2, and had SOPs to guide use of Annex 2 in diverse settings, suggests that cross-national management systems are in place to effectively notify WHO of potential PHEICs.
Our findings also suggest that NFPs generally perceived Annex 2 to be very user-friendly. NFPs cited the timeline for notification of a potential PHEIC as reasonable and that the algorithm and checklists represented a substantial improvement over the previous IHR disease list. Overall, NFPs felt that Annex 2 was simple to read and clear, particularly when applied to communicable diseases. However, NFPs described having difficulties in gauging the severity of certain types of public health events, given the absence of evidence-based thresholds (e.g. contamination of food and water, infectious diseases among animals and chemical contamination of products or the environment). These findings are consistent with a published reported from one State Party in sub-Saharan Africa that indicated the country lacked surveillance guidelines and case definitions for outbreak response to food, chemical and radio-nuclear hazards . In developing countries, effective detection of food and water-borne diseases requires significant improvements in laboratory infrastructure and expertise . Meanwhile, the surveillance and reporting of chemical, nuclear and radiological threats have been described as persistent challenges by several States Parties in both developing and developed countries , complicating planning for major incidents . Further guidance where possible, on global standardization of rare types of public health events were deemed necessary by NFPs.
Our findings regarding NFP awareness, knowledge and efforts to integrate Annex 2 into national legislation, organizational procedures and communication systems appears to be in direct contrast with results from the recent WHO Database Study which found that notification of public health events by NFPs has remained quite limited . A potential explanation for this discordance is that Annex 2 was designed and written in such a way as to be intentionally non-specific. It has been assumed that this intentional ambiguity would broaden the type and numbers of notifiable events under the IHR (2005) and lead to an over-reporting of public health events by National IHR Focal Points to WHO. However, that intentional ambiguity may actually be having the opposite effect. Lack of detail in Annex 2 may in fact have allowed more discretion in reporting which in turn could have resulted in more conservative notification practices.
Implications of Findings
There are several steps WHO and States Parties can take to further improve the use of Annex 2 (Additional File 2). Since having a thorough and confident understanding of Annex 2 was associated with having accessed WHO guidance and training on the tool, there is a need to ensure that all NFPs access some form of training regarding Annex 2, and especially the WHO's Guidance for the Use of Annex 2 of the IHR(2005) . A mechanism to prevent the non-specificity of Annex 2 as a reason to err on the side of not reporting and to support NFPs in any internal disputes over notification, would be to provide more specific examples of what classes of conditions would require reporting through an increased number of case scenarios. If a case study of an analogous event suggested that reporting is required it could reduce discretion resulting in the decision to not report. NFPs unanimously found the case scenarios contained within WHO's Interim Guidance for the Use of Annex 2 of the IHR(2005) to be helpful for obtaining a strong working knowledge of the tool.
Several States Parties have demonstrated a tremendous amount of innovation with regard to activities they have taken to support Annex 2. In some circumstances, these activities to support Annex 2 may constitute 'best practices' that other States Parties can learn from and warrant closer attention. There is equally a need for WHO to develop parameters for the appropriation/modification of Annex 2 by States Parties. Furthermore, while the intention and one of the great strengths of Annex 2 is to require an interpretation of public health events taking into account the context in which they occur, there is scope for WHO to support NFPs in their notification assessment by developing thresholds for the seriousness and risk of spread for specific events and circumstances.
The majority of NFPs supported the use of a centralized, web-based platform to simultaneously strengthen training in the use of Annex 2, information sharing with NFPs from neighboring States Parties, and notification of potential PHEICs to WHO, Internet-based reporting has been associated with increased timeliness of outbreak detection and public communication , and is becoming increasingly feasible in developing countries due to growing Internet access, IT user-friendliness and reduced costs . Automated syndromic surveillance system could complement existing laboratory and public health surveillance programs, and be maintained with minimal investment into technological or human resources .
When considering the findings of our study it is important to recognize the limitations of the methodology. First, our evaluation sampled NFPs. These individuals would be expected to be amongst the most supportive and knowledgeable individuals of the IHR (2005) within a State Party. Similar enthusiasm and knowledge for the IHR cannot necessarily be expected to exist in other parts of the public health surveillance and response system and could reflect on the ability of a States Party to utilize Annex 2. Furthermore NFPs may not necessarily play the key role in the risk assessment of an event occurring within the territory of a given State Party. This process may involve decision makers based outside the respective NFP. While the studies were addressed to NFPs, the only national stakeholder clearly identifiable and accessible by WHO, no restrictions were imposed on NFPs regarding consultation with other relevant decision makers. However, because of the anonymous nature of the survey we do not know whether the answers that we received from NFPs represent the views of individual risk assessors within the NFP, the entire NFP team, or a group of collaborators including national experts outside of the NFP. Additionally, our findings are susceptible to responder bias. NFPs that did participate may have been systematically different from those that did not. In particular we noted a differential response per WHO Region, with comparatively less responses from the Eastern Mediterranean and South East Asia, and more responses from the Americas and Europe. Non-response from certain States Parties may be explained by individual circumstances (e.g. workload), cultural norms, or participant exhaustion (from other recent WHO evaluation ). Future evaluations should seek to verify whether observations from the present study are representative of those regions. Also, for those NFPs we obtained responses from, there is the risk of social desirability bias. It is possible, for example, that participants modified their responses (e.g. regarding awareness, knowledge, usefulness of Annex 2) in order to satisfy WHO headquarters representatives associated with the study. Finally, descriptive results from this study should be interpreted as baseline data for subsequent in depth analysis and longitudinal investigation.