An experimental game to assess hunter's participation in zoonotic diseases surveillance

BACKGROUND

Strengthening the surveillance of zoonotic diseases emergence in the wild meat value chains is a critical component of the prevention of future health crises. Community hunters could act as first-line observers in zoonotic pathogens surveillance systems in wildlife, by reporting early signs of the possible presence of a disease in the game animals they observe and manipulate on a regular basis.

METHODS

An experimental game was developed and implemented in a forested area of Gabon, in central Africa. Our objective was to improve our understanding of community hunters' decision-making when finding signs of zoonotic diseases in game animals: would they report or dissimulate these findings to a health agency? 88 hunters, divided into 9 groups of 5 to 13 participants, participated in the game, which was run over 21 rounds. In each round the players participated in a simulated hunting trip during which they had a chance of capturing a wild animal displaying clinical signs of a zoonotic disease. When signs were visible, players had to decide whether to sell/consume the animal or to report it. The last option implied a lowered revenue from the hunt but an increased probability of early detection of zoonotic diseases with benefits for the entire group of hunters.

RESULTS

The results showed that false alerts-i.e. a suspect case not caused by a zoonotic disease-led to a decrease in the number of reports in the next round (Odds Ratio [OR]: 0.46, 95% Confidence Interval [CI]: 0.36-0.8, p < 0.01). Hunters who had an agricultural activity in addition to hunting reported suspect cases more often than others (OR: 2.05, 95% CI: 1.09-3.88, p < 0.03). The number of suspect case reports increased with the rank of the game round (Incremental OR: 1.11, CI: 1.06-1.17, p < 0.01) suggesting an increase in participants' inclination to report throughout the game.

CONCLUSION

Using experimental games presents an added value for improving the understanding of people's decisions to participate in health surveillance systems.

Operationalizing One Health: Environmental Solutions for Pandemic Prevention

Human pressure on the environment is increasing the frequency, diversity, and spatial extent of disease outbreaks. Despite international recognition, the interconnection between the health of the environment, animals, and humans has been historically overlooked. Past and current initiatives have often neglected prevention under the One Health preparedness cycle, largely focusing on post-spillover stages. We argue that pandemic prevention initiatives have yet to produce actionable targets and indicators, connected to overarching goals, like it has been done for biodiversity loss and climate change. We show how the Driver-Pressure-State-Impact-Response framework, already employed by the Convention on Biological Diversity, can be repurposed to operationalize pandemic prevention. Global responses for pandemic prevention should strive for complementarity and synergies among initiatives, better articulating prevention under One Health. Without agreed-upon goals underpinning specific targets and interventions, current global efforts are unlikely to function at the speed and scale necessary to decrease the risk of disease outbreaks that might lead to pandemics. Threats to the environment are not always abatable, but decreasing the likelihood that environmental pressure leads to pandemics, and developing strategies to mitigate these impacts, are both attainable goals.

Elasticity and substitutability of food demand and emerging disease risk on livestock farms

Disease emergence in livestock is a product of environment, epidemiology and economic forces. The environmental factors contributing to novel pathogen emergence in humans have been studied extensively, but the two-way relationship between farm microeconomics and outbreak risk has received comparably little attention. We introduce a game-theoretic model where farmers produce and sell two goods, one of which (e.g. pigs, poultry) is susceptible to infection by a pathogen. We model market and epidemiological effects at both the individual farm level and the community level. We find that in the case of low demand elasticity for livestock meat, the presence of an animal pathogen causing production losses can lead to a bistable system where two outcomes are possible: (i) successful disease control or (ii) maintained disease circulation, where farmers slaughter their animals at a low rate, face substantial production losses, but maintain large herds because of the appeal of high meat prices. Our observations point to the potentially critical effect of price elasticity of demand for livestock products on the success or failure of livestock disease control policies. We show the potential epidemiological benefits of (i) policies aimed at stabilizing livestock product prices, (ii) subsidies for alternative agricultural activities during epidemics, and (iii) diversifying agricultural production and sources of proteins available to consumers.

Molecular and clinical diversity in primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare and distinct entity within diffuse large B-cell lymphoma presenting with variable response rates probably to underlying molecular heterogeneity.

PATIENTS AND METHODS

To identify and characterize PCNSL heterogeneity and facilitate clinical translation, we carried out a comprehensive multi-omic analysis [whole-exome sequencing, RNA sequencing (RNA-seq), methylation sequencing, and clinical features] in a discovery cohort of 147 fresh-frozen (FF) immunocompetent PCNSLs and a validation cohort of formalin-fixed, paraffin-embedded (FFPE) 93 PCNSLs with RNA-seq and clinico-radiological data.

RESULTS

Consensus clustering of multi-omic data uncovered concordant classification of four robust, non-overlapping, prognostically significant clusters (CS). The CS1 and CS2 groups presented an immune-cold hypermethylated profile but a distinct clinical behavior. The 'immune-hot' CS4 group, enriched with mutations increasing the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor-κB activity, had the most favorable clinical outcome, while the heterogeneous-immune CS3 group had the worse prognosis probably due to its association with meningeal infiltration and enriched HIST1H1E mutations. CS1 was characterized by high Polycomb repressive complex 2 activity and CDKN2A/B loss leading to higher proliferation activity. Integrated analysis on proposed targets suggests potential use of immune checkpoint inhibitors/JAK1 inhibitors for CS4, cyclin D-Cdk4,6 plus phosphoinositide 3-kinase (PI3K) inhibitors for CS1, lenalidomide/demethylating drugs for CS2, and enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) inhibitors for CS3. We developed an algorithm to identify the PCNSL subtypes using RNA-seq data from either FFPE or FF tissue.

CONCLUSIONS

The integration of genome-wide data from multi-omic data revealed four molecular patterns in PCNSL with a distinctive prognostic impact that provides a basis for future clinical stratification and subtype-based targeted interventions.

A participatory approach for building ex ante impact pathways towards a prudent use of antimicrobials in pig and poultry sectors in France

Antimicrobial resistance (AMR) is a global public health threat responsible for 700,000 deaths per year worldwide. There is scientific evidence of the causal relationship between antimicrobial use (AMU) along the food chain and AMR. Improving AMU in livestock is therefore a key component in the fight against AMR. To improve AMU in livestock, there is no one-size-fits-all solution and strategies must be context-adapted and socially acceptable for actors in order to increase AMU sustainability. AMU decision-making is based on an interdependent set of economic, behavioral, ethical, and cultural factors that need to be assessed to advise on the potential impacts of measures. We hypothesized that a participatory strategic planning approach may increase the plausibility and the efficacy of the strategies formulated by facilitating the dialogue between actors of diverse backgrounds, stimulating innovative thinking and constant considerations of contextual factors, actors and impacts. We adapted and applied the ImpresS ex ante approach (IMPact in reSearch in the South, https://impress-impact-recherche.cirad.fr/) within a Living Lab engaging actors from the French pig and poultry sectors in co-creation of innovative strategies towards improved AMU. We conducted semi-structured interviews and participatory workshops between April 2021 and March 2022. The results describe 1) an initial diagnosis of the current AMU situation in the pig and poultry sectors in France; 2) a common vision of the future to which participants would like to contribute through the intervention; 3) an identification of the current problems opposed to this vision of the future; 4) a defined scope of the intervention; 5) a typology of actors protagonist or impacted by those issues and 6) outcome maps to solve a priority problem related to indicators and monitoring. This study provides recommendations for decision-makers on plausible and innovative strategies to sustainably improve AMU in pig and poultry sectors in France and evidence of the benefits of participatory strategic planning approaches.

COVID-19 in Africa: Underreporting, demographic effect, chaotic dynamics, and mitigation strategy impact

The epidemic of COVID-19 has shown different developments in Africa compared to the other continents. Three different approaches were used in this study to analyze this situation. In the first part, basic statistics were performed to estimate the contribution of the elderly people to the total numbers of cases and deaths in comparison to the other continents; Similarly, the health systems capacities were analysed to assess the level of underreporting. In the second part, differential equations were reconstructed from the epidemiological time series of cases and deaths (from the John Hopkins University) to analyse the dynamics of COVID-19 in seventeen countries. In the third part, the time evolution of the contact number was reconstructed since the beginning of the outbreak to investigate the effectiveness of the mitigation strategies. Results were compared to the Oxford stringency index and to the mobility indices of the Google Community Mobility Reports.

Compared to Europe, the analyses show that the lower proportion of elderly people in Africa enables to explain the lower total numbers of cases and deaths by a factor of 5.1 on average (from 1.9 to 7.8). It corresponds to a genuine effect. Nevertheless, COVID-19 numbers are effectively largely underestimated in Africa by a factor of 8.5 on average (from 1.7 to 20. and more) due to the weakness of the health systems at country level. Geographically, the models obtained for the dynamics of cases and deaths reveal very diversified dynamics. The dynamics is chaotic in many contexts, including a situation of bistability rarely observed in dynamical systems. Finally, the contact number directly deduced from the epidemiological observations reveals an effective role of the mitigation strategies on the short term. On the long term, control measures have contributed to maintain the epidemic at a low level although the progressive release of the stringency did not produce a clear increase of the contact number. The arrival of the omicron variant is clearly detected and characterised by a quick increase of interpeople contact, for most of the African countries considered in the analysis.

Evaluation of Public–Private Partnership in the Veterinary Domain Using Impact Pathway Methodology: In-depth Case Study in the Poultry Sector in Ethiopia

Public–private partnerships (PPPs) in the veterinary domain are joint approaches in which public veterinary services and private actors such as private veterinarians, producers' associations, or private companies work together to address complex animal health challenges. They are implemented worldwide and can help to strengthen the capacities of veterinary services, but few have been evaluated. None of the evaluations developed in the veterinary domain explicitly addressed PPPs, their complex program design, their evolving governance, and coordination system, and their impacts. This work represents the first application of the participatory impact pathway methodology for the evaluation of a PPP in the veterinary domain. The PPP evaluated aimed at developing the poultry sector in Ethiopia and improving poultry health service coverage, particularly in remote areas. The combination of semi-structured interviews (n = 64) and collective reflection during three workshops (n participants = 26, 48, 18), captured the viewpoints of public and private partners, actors who influenced the partnership, and actors impacted by it. The context of the PPP was analyzed, and the causal relationships between the PPP and its impacts were investigated. This work showed that collaboration between the public and private sector occurred at several administrative levels. The actors considered a variety of impacts, on the economy, business, trust, and health, which were then measured through different indicators. The actors also identified the added value of the PPP to enrich those impacts. The participatory impact pathway methodology helped to strengthen the engagement of actors in the PPP and to formulate recommendations at the policy level to favor positive results. This case study represents a milestone in building a participatory evaluation framework of PPP in the veterinary domain.

Antimicrobial Resistance in Africa-How to Relieve the Burden on Family Farmers

Although currently available data indicate that Africa has the lowest usage of antimicrobials in animals in the world (adjusted by animal biomass), data show a high prevalence of antimicrobial resistance in foodborne pathogens isolated from animals and animal products. Apart from the lack of solid data on antimicrobial use in many countries in Africa, different hypotheses could explain this situation. Qualitative interviews of farmers show a lack of knowledge and uninformed use of antimicrobials. Considering the development of animal farming to meet an increasing demand for proteins, this deficiency represents a serious public health issue. We advocate for policies that consider the specific challenges faced by family farmers in Africa, to simultaneously improve access to veterinary drugs while strengthening the regulation of their use. We propose a global approach targeting the agri-food system, offering innovative social and technical interventions on antimicrobial usage, adapted to family farmers.

An evaluation tool to strengthen the collaborative process of the public-private partnership in the veterinary domain

Public-private partnerships (PPPs) in the veterinary domain are widely implemented worldwide and can help to strengthen the capacities of Veterinary Services. Few analyses have been made of these initiatives. This study is aimed at developing an evaluation tool based on participatory approaches and focusing on the quality of PPP processes in the veterinary domain. The tool was divided into ten sections relevant to PPP process organisation and activities. The 44 evaluation criteria and six quality attributes (operationality, relevance, acceptability, inclusiveness, adaptability, and stability) were identified based on literature review and case-study application. The tool was adjusted during four regional PPP training workshops bringing together stakeholders from both public and private sectors. Finally, the tool was validated through an experts' elicitation process and applied in the field in Paraguay. The tool was developed in a non-normative perspective to help the partners adapt the PPP to their specific context, to maximize the opportunities and minimize the risks of such collaborations, and to formulate adapted recommendations to strengthen and improve the PPP collaborative process and thus the outcomes. In an ex-ante perspective, this tool would also help public and private actors to engage and develop a PPP process following the best possible practices. The aim of this tool is to help decision making in terms of PPP development and implementation in the veterinary domain to ensure the added value and relevance of such a collaborative approach in different countries worldwide.

[Infection associated cerebral vasculitis]

Infections are a frequent cause of cerebral vasculitis, important to diagnose because a specific treatment may be required. Infection-associated vasculitis can be caused by angiotropic pathogens (varicella zoster virus, syphilis, aspergillus). They can be associated with subarachnoidal meningitis (tuberculosis, pyogenic meningitis, cysticercosis). They can appear contiguously to sinuses or orbital infection (aspergillosis, mucormycosis). Finally, they also may be due to an immune mechanism in the context of chronic infections (hepatitis B virus, hepatitis C virus, human immunodeficiency virus). Cerebral vasculitis are severe conditions and their prognosis is directly linked to early recognition and diagnosis. Infectious causes must therefore be systematically considered ahead of cerebral vasculitis, and the appropriate investigations must be determined according to the patient's clinical context. We propose here an update on the infectious causes of cerebral vasculitis, their diagnosis modalities, and therapeutic options.

Evaluation of vaccination strategies to control an avian influenza outbreak in French poultry production networks using EVACS tool

France recently faced two epizootic waves of highly pathogenic avian influenza (HPAI) in poultry (H5N6 in 2015-2016 and H5N8 in 2016-2017), mainly in the fattening duck production sector. Vaccination against avian influenza (AI) is currently not authorised in France even though its potential benefits were discussed during these epizootic events. The objective of this work was to evaluate the potential efficiency of different vaccination strategies that could be applied against AI in France. The EVACS tool, which is a decision support tool developed to evaluate vaccination strategies, was applied in several French poultry production sectors: broiler, layer, turkey, duck and guinea fowl. EVACS was used to simulate the performance of vaccination strategies in terms of vaccination coverage, immunity levels and spatial distribution of the immunity level. A cost-benefit analysis was then applied based on EVACS results to identify the most efficient strategy. For each sector, vaccination protocols were tested according to the production type (breeders/production, indoor/outdoor), the integration level (integrated/independent) and the type of vaccine (hatchery vaccination using a recombinant vaccine/farm vaccination using an inactivated vaccine). The most efficient protocols for each sector were then combined to test different overall vaccination strategies at the national level. Even if it was not possible to compare vaccination protocols with the two vaccines types in "foie gras" duck, meat duck and guinea fowl production sectors as no hatchery vaccine currently exist for these species, these production sectors were also described and included in this simulation. Both types of vaccination (at hatchery and farm level) enabled protective immunity levels for the control of AI, but higher poultry population immunity level was reached (including independent farms) using hatchery vaccination. We also showed that hatchery vaccination was more efficient (higher benefit-cost ratio) than farm vaccination. Sufficient and homogeneously spatially distributed protective levels were reached in the overall poultry population with vaccination strategies targeting breeders, chicken layers and broilers and turkeys, without the need to include ducks and guinea fowls. However, vaccination strategies involving the highest number of species and production types were the most efficient in terms of cost-benefit. This study provides critical information on the efficiency of different vaccination strategies to support future decision making in case vaccination was applied to prevent and control HPAI in France.

Chaos theory applied to the outbreak of COVID-19: an ancillary approach to decision making in pandemic context

While predicting the course of an epidemic is difficult, predicting the course of a pandemic from an emerging virus is even more so. The validity of most predictive models relies on numerous parameters, involving biological and social characteristics often unknown or highly uncertain. Data of the COVID-19 epidemics in China, Japan, South Korea and Italy were used to build up deterministic models without strong assumptions. These models were then applied to other countries to identify the closest scenarios in order to foresee their coming behaviour. The models enabled to predict situations that were confirmed little by little, proving that these tools can be efficient and useful for decision making in a quickly evolving operational context.

Surveillance of swine influenza viruses in sentinel familial farms in Hung Yen province in Northern Vietnam in 2013-2014

From May 2013 to April 2014, 15 swine family-run farms (17 pig litters) in two districts in Hung Yen province, near Hanoi, were virologically and epizootiologically monitored for swine influenza viruses (SIV) monthly. No SIV was isolated from nasal swabs. Maternal antibodies were detected in 10 litters, and seroconversion against SIV was detected in six litters. There was a marked difference in patterns of SIV transmission in the two districts. Van Lam district which has low density of swine with mainly smallholder farms had low intensity of SIV, with much of the infection caused by H1N1 2009 pandemic-like viruses A(H1N1)pdm09, likely originated from humans. In contrast, Van Giang district, which has high swine density and larger farms, had high levels of typical SIV (triple reassortants H3N2 and H3N2 Binh Duong lineage viruses) circulating within swine. With one exception, the SIV lineages detected were those we concurrently isolated from studies in a large central abattoir in Hanoi. Influenza-like illness symptoms reported by farmers were poorly correlated with serological evidence of SIV infection.

Assessing the Adoption of Recommended Standards, Novel Approaches, and Best Practices for Animal Health Surveillance by Decision Makers in Europe

Animal health surveillance is an important tool for disease mitigation and helps to promote animal health and welfare, protect human health, support efficient animal production, and enable trade. This study aimed to assess adoption of recommended standards and best practice for surveillance (including risk-based approaches) in Europe. It included scoping interviews with surveillance experts in Denmark, the Netherlands, Norway, and Switzerland to gather information on knowledge acquisition, decisions and implementation of surveillance, and perceptions. This was followed by an online survey among animal health and food safety surveillance users in EU, EEA, and Schengen countries. A total of 166 responses were collected from 27 countries; 111 were eligible for analysis. A strong preference for legislation and established standards was observed, with peer-reviewed publications, conferences, symposia, and workshops to be major sources of information. The majority of respondents indicated a need for international evaluation for surveillance and implied that considerations of cost-effectiveness were essential when making a decision to adopt new surveillance standards. However, most of the respondents did not use a formal evaluation to inform the adoption of new standards or only conducted a descriptive assessment before their implementation or adaptation. Only a few respondents reported a quantitative economic evaluation despite economic efficiency being considered as a highly relevant criterion for surveillance implementation. Constraints mentioned in the adoption of new surveillance standards included insufficient time, financial and human resources, and lack of competency. Researchers aiming to achieve impact by their surveillance work are advised to consider ways of influencing binding standards and to disseminate their work pro-actively using varied channels of engagement tailored to relevant target audiences and their needs. Generally, a more formal linkage between surveillance information and disease mitigation decisions-for example, by using systematic evaluation-could help increase the economic value of surveillance efforts. Finally, a collaborative, international platform for exchange and learning on surveillance as well as co-design and dissemination of surveillance standards is recommended.

Typological analysis of public-private partnerships in the veterinary domain

Public-Private Partnerships (PPPs) are defined as a collaborative approach in which the public and private sector share resources, responsibilities and risks to achieve common objectives and mutual benefits in a sustainable manner. PPPs are identified as a key solution to reinforce Veterinary Services. However only limited information is available on the scope, added value and enabling factors of PPPs in this sector. The aims of this study were to develop a typology of PPPs in the veterinary field and to identify key success factors and obstacles to their implementation. A structured questionnaire was sent to all 181 World Organisation for Animal Health (OIE) Member Countries and to 47 private contacts. 36 different variables characterizing PPP initiatives were collected. 97 examples of PPPs were retrieved from 76 countries. Dimensionality reduction techniques were combined with clustering and discrimination methods to establish a typology of PPPs and to derive a set of simple rules to classify new instances of PPPs. Three clusters were identified, separated according to two main variables: the type of private partners and the type of interaction. Cluster 1, transactional PPPs, represented the traditional understanding of PPPs by Veterinary Services, initiated and funded by the public sector, giving service delivery accreditation to mostly private veterinarians; cluster 2, collaborative PPPs, included partnerships between producer associations and public Veterinary Services, driven by trade interests; cluster 3, transformational PPPs, represented joint programs initiated and funded by private companies and initially driven by business development objectives. Specific success factors and key obstacles affecting the performances and sustainability of these initiatives were identified for each cluster. This study represents the first practical attempt to develop a meaningful typology of PPPs in the field of animal health and to identify fundamental obstacles currently inhibiting the development of PPPs, and suggests ways to support national Veterinary Services in overcoming these obstacles.

OS8.5 How to assess meningioma therapy activity: The CEVOREM independent central review experience

BACKGROUND

Meningioma therapy efficiency is used to being assessed by 6 months progression survival rate (PFS6), which remains the most consensual criterion. Nevertheless, different patterns of meningiomas intrinsic aggressiveness and growth rates directly impact the PFS6 leading to unreliability of drug effect assessment. Moreover, therapeutic response remains rare in meningiomas. These points lead to consider classical and updated RANO criteria as not fully adapted to meningiomas. Based on phase II CEVOREM trial experience, we aim to improve the assessment of drugs efficiency in meningiomas via the determination of growth rate before and under treatment.

MATERIAL AND METHODS

Twenty patients were included in Cevorem trial which tested the combination of octreotide and everolimus as previously described. MRI assessment was performed in the 3 to 6 preinclusion months, at inclusion then every 3 months. Progression was assessed by investigators according to RANO criteria. An independent central review was performed with 2 reviewers and 1 adjudicator: largest diameter, 2D maximal area as 3D volume were assessed by autosegmentation software (Brainlab). Results from central review were correlated to investigators assessment. 3D volume growth rate (3DVGR) was calculated using 2 different processes (one simple and one complex). Comparison of 3DVGR before vs. under treatment was performed. Meningioma growth under treatment was compared to theoretical meningioma growth based on preinclusion data using a model of meningioma growth.

RESULTS

PFS6 assessed via the independent central review was in accordance with PFS6 assessed by investigators following RANO criteria. Then, we analyzed 3DVGR before and during therapy. Standard deviation was higher using the complex 3DVGR calculation process. A decrease of more than 50% of the 3DVGR was observed in 30/36 tumors at 3 months with the both calculation modes and could be considered as a threshold of drugs activity. Median volume growth rate decreased from 88.3 or 17.2%/3 months before inclusion to -2.2 or à -0.6 %/3mo at 3 months depending of the calculation mode (p <0.0002). Nevertheless, in our study, decrease in 3DVGR was associated with a prolonged free progression period when 3DVGR decreased around 0 or negative. Comparison of theoretical meningioma growth curve based on preinclusion data with under treatment growth curve is ongoing. Some limits remain: 3DVGR calculation remains directly related to the volume assessment accuracy and 3DVGR can be very high particularly in case of very small initial tumor which cannot be mitigated by current mathematical models.

CONCLUSION

3DVGR measurement during versus before seems as a sensitive and reliable tool which provides valuable comparison in a phase 2 study to assess drugs activity in meningioma in complement to PFS6. 3DVGR assessment should be considered in future clinical trials.

Valuing Health Surveillance as an Information System: Interdisciplinary Insights

The economic evaluation of health surveillance systems and of health information is a methodological challenge, as for information systems in general. Main present threads are considering cost-effectiveness solutions, minimizing costs for a given technically required output, or cost-benefit analysis, balancing costs with economic benefits of duly informed public interventions. The latter option, following a linear command-and-control perspective, implies considering a main causal link between information, decision, action, and health benefits. Yet, valuing information, taking into account its nature and multiple sources, the modalities of its processing cycle, from production to diffusion, decentralized use and gradual building of a shared information capital, constitutes a promising challenge. This work proposes an interdisciplinary insight on the value of health surveillance to get a renewed theoretical framework integrating information and informatics theory and information economics. The reflection is based on a typological approach of value, basically distinguishing between use and non-use values. Through this structured discussion, the main idea is to expand the boundaries of surveillance evaluation, to focus on changes and trends, on the dynamic and networked structure of information systems, on the contribution of diverse data, and on the added value of combining qualitative and quantitative information. Distancing itself from the command-and-control model, this reflection considers the behavioral fundaments of many health risks, as well as the decentralized, progressive and deliberative dimension of decision-making in risk management. The framework also draws on lessons learnt from recent applications within and outside of health sector, as in surveillance of antimicrobial resistance, inter-laboratory networks, the use of big data or web sources, the diffusion of technological products and large-scale financial risks. Finally, the paper poses the bases to think the challenge of a workable approach to economic evaluation of health surveillance through a better understanding of health information value. It aims to avoid over-simplifying the range of health information benefits across society while keeping evaluation within the boundaries of what may be ascribed to the assessed information system.

[Management of tumoral epilepsy in meningioma surgery: Review of the literature and survey of French national practices]

Prophylaxis or treatment of tumor-associated seizures is adaily concern in neurosurgical practice but is often guided by the surgeon's habits rather than evidence from clinical trials, which is lacking. The present study reviews the literature on the incidence, clinical aspects and treatment of epilepsy and epileptic seizures in patients undergoing surgery for meningioma. Based on the published data, we then performed a French nationwide survey of neurosurgeons' practices regarding perioperative management of meningioma-related epilepsy and epileptic seizures.

Satisfaction with sexual life in people living with HIV/AIDS: the persistent weight of the fear of transmission

Sexual life is an important dimension of quality of life, which may be affected by the fear of transmission in people living with HIV/AIDS (PLWHA), despite the fact that antiretroviral therapy prevents person-to-person transmission. We, therefore, aimed to explore the sexual life satisfaction of PLWHA and its correlation with their fear of HIV transmission and self-esteem. Consecutive adult PLWHA from seven HIV care facilities in the Rhone-Alpes region, France, were asked to complete a self-administered, anonymous questionnaire concerning sociological and medical data, satisfaction with sexual life (18 questions), and self-esteem (Rosenberg score). Overall, 690 PLWHA answered the questionnaire (mean age 49.2 ± 11 years); 74.9% were men, of which 75.1% had sex with men. Overall, 68.0% of respondents feared transmitting HIV (a lot/a bit). A lower satisfaction with sexual life was significantly associated with being female, not having a stable sexual partner, being unemployed, having a low income, experiencing a fear of HIV transmission, having lower self-esteem, and not reporting an excellent/very good health status. These results strongly suggest that the information concerning the antiretroviral-induced suppression of infectivity should be widely diffused, as this may enhance the quality of sexual life in PLWHA.

Benefit-Cost Analysis of Foot-and-Mouth Disease Vaccination at the Farm-Level in South Vietnam

This study aimed to analyze the financial impact of foot-and-mouth disease (FMD) outbreaks in cattle at the farm-level and the benefit–cost ratio (BCR) of biannual vaccination strategy to prevent and eradicate FMD for cattle in South Vietnam. Production data were collected from 49 small-scale dairy farms, 15 large-scale dairy farms, and 249 beef farms of Long An and Tay Ninh province using a questionaire. Financial data of FMD impacts were collected using participatory tools in 37 villages of Long An province. The net present value, i.e., the difference between the benefits (additional revenue and saved costs) and costs (additional costs and revenue foregone), of FMD vaccination in large-scale dairy farms was 2.8 times higher than in small-scale dairy farms and 20 times higher than in beef farms. The BCR of FMD vaccination over 1 year in large-scale dairy farms, small-scale dairy farms, and beef farms were 11.6 [95% confidence interval (95% CI) 6.42–16.45], 9.93 (95% CI 3.45–16.47), and 3.02 (95% CI 0.76–7.19), respectively. The sensitivity analysis showed that varying the vaccination cost had more effect on the BCR of cattle vaccination than varying the market price. This benefit-cost analysis of biannual vaccination strategy showed that investment in FMD prevention can be financially profitable, and therefore sustainable, for dairy farmers. For beef cattle, it is less certain that vaccination is profitable. Additional benefit-cost analysis study of vaccination strategies at the national-level would be required to evaluate and adapt the national strategy to achieve eradication of this disease in Vietnam.

The Value Chain Approach in One Health: Conceptual Framing and Focus on Present Applications and Challenges

The value chain (VC) is a major operational concept for socioeconomic analysis at meso level. Widely mobilized in development practice, it is still undergoing conceptual and practical refining, e.g., to take account of environmental and social sustainability. Briefly, VC refers to a system of value creation through the full set of actors, links, technical and commercial activities and flows involved in the provision of a good or service on a market. In the past decade, this concept has been promoted in the management of animal health. In particular, the emergence of highly pathogenic avian influenza (HPAI) has triggered an interdisciplinary dynamic including VC analysis as a central tool. These efforts promoted participatory investigation methods in the analysis of health systems. Using qualitative and quantitative data, these methods acknowledge the usefulness of actors’ involvement and knowledge, hence facilitating the transdisciplinarity needed for effective action. They fit into adaptive and action-oriented strategies, fostering stakeholders’ participation. Recent research on HPAI surveillance in South-East Asia merged VC and participatory approaches to develop innovative tools for analyzing constraints to information flow. On-going interventions for HPAI prevention and control as well as the prevention of other emerging zoonotic risks in Africa are presently building on this VC framework to develop strategies for its application at national and regional scales. Based on the latter experiences, this article proposes a field-based perspective on VC applications to animal and public health systems, within a One Health approach responding to the overall challenge of complexity.

Economic factors influencing zoonotic disease dynamics: demand for poultry meat and seasonal transmission of avian influenza in Vietnam

While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods - wavelet analysis, economic analysis, statistical and disease transmission modelling - we aimed to explore the influence of climatic and economic factors on the seasonality of H5N1 Highly Pathogenic Avian Influenza in the domestic poultry population of Vietnam. We found that while climatic variables are associated with seasonal variation in the incidence of avian influenza outbreaks in the North of the country, this is not the case in the Centre and the South. In contrast, temporal patterns of H5N1 incidence are similar across these 3 regions: periods of high H5N1 incidence coincide with Lunar New Year festival, occurring in January-February, in the 3 climatic regions for 5 out of the 8 study years. Yet, daily poultry meat consumption drastically increases during Lunar New Year festival throughout the country. To meet this rise in demand, poultry production and trade are expected to peak around the festival period, promoting viral spread, which we demonstrated using a stochastic disease transmission model. This study illustrates the way in which economic factors may influence the dynamics of livestock pathogens.

Added Value of Avian Influenza (H5) Day-Old Chick Vaccination for Disease Control in Egypt

The immunity profile against H5N1 highly pathogenic avian influenza (HPAI) in the commercial poultry value chain network in Egypt was modeled with the use of different vaccination scenarios. The model estimated the vaccination coverage, the protective seroconversion level, and the duration of immunity for each node of the network and vaccination scenario. Partial budget analysis was used to compare the benefit-cost of the different vaccination scenarios. The model predicted that targeting day-old chick avian influenza (AI) vaccination in industrial and large hatcheries would increase immunity levels in the overall poultry population in Egypt and especially in small commercial poultry farms (from <30% to >60%). This strategy was shown to be more efficient than the current strategy of using inactivated vaccines. Improving HPAI control in the commercial poultry sector in Egypt would have a positive impact to improve disease control.

A Q Method Approach to Evaluating Farmers' Perceptions of Foot-and-Mouth Disease Vaccination in Vietnam

This study aims to explore the farmers’ perceptions of foot-and-mouth disease (FMD) vaccination using a reflexive research method called Q methodology. A structured sample was composed of 46 farmers selected according to gender, farming experience, level of education, and production type. Statements relevant to the farmers’ perceptions of and attitudes toward FMD vaccination, related to confidence, logistics, costs, and impacts of vaccination were developed. Results were analyzed by principal component analysis and factor analysis. The influence of demographics and characterized variables on the respondent’s contribution to each factor was also tested. Regarding the different beliefs and behavior toward FMD vaccination, the common perceptions held by Vietnamese cattle and pig farmers were divided into three discourses named Confidence (24 subjects), Belief (12 subjects), and Challenge (6 subjects). The identified discourses represented 57.3% of the variances. Consensus points were found, such as the feeling of being more secure after FMD vaccination campaigns; the fact that farmers take vaccination decisions themselves without being influenced by other stakeholders; the opinion that FMD vaccination is cheaper than the costs of treating a sick animal; and that vaccines provided by governmental authorities are of high quality. Part of the studied population did not consider vaccination to be the first choice strategy in prevention. This raises the question of how to improve the active participation of farmers in the FMD vaccine strategy. Taking into consideration farmers’ perceptions can help to implement feasible vaccination strategies at the local level.

Epidemiological features of influenza circulation in swine populations: A systematic review and meta-analysis

Background

The emergence of the 2009 influenza pandemic virus with a swine origin stressed the importance of improving influenza surveillance in swine populations. The objectives of this systematic review and meta-analysis were to describe epidemiological features of swine influenza (SI) across the world and identify factors impacting swine influenza virus surveillance.

Methods

The systematic review followed the PRISMA guidelines. Articles published after 1990 containing data on SI on pig and herd-level seroprevalence, isolation and detection rates, and risk factors were included. Meta-regression analyses using seroprevalence and virological rates were performed.

Results

A total of 217 articles were included. Low avian influenza (AI) seroprevalence (means pig = 4.1%; herd = 15%) was found, showing that AIV do not readily establish themselves in swine while SIV seroprevalence was usually high across continents (influenza A means pig = 32.6–87.8%; herd = 29.3–100%). Higher pig density and number of pigs per farm were shown by the meta-regression analyses and/or the risk factor articles to be associated with higher SI seroprevalence. Lower seroprevalence levels were observed for countries with low-to-medium GDP. These results suggest that larger industrial farms could be more at risk of SIV circulation. Sampling swine with influenza-like illness (ILI) was positively associated with higher isolation rates; most studies in Europe, Latin and North America were targeting swine with ILI.

Conclusions

To improve understanding of SI epidemiology, standardization of the design and reporting of SI epidemiological studies is desirable. Performance of SI surveillance systems in low-to-medium GDP countries should be evaluated to rule out technical issues linked to lower observed SIV prevalence. Targeting certain swine age groups, farming systems and swine with ILI may improve the surveillance cost-effectiveness. However, focusing on pigs with ILI may bias virus detection against strains less virulent for swine but which may be important as pandemic threats.

One Health Economics to confront disease threats

Global economic impacts of epidemics suggest high return on investment in prevention and One Health capacity. However, such investments remain limited, contributing to persistent endemic diseases and vulnerability to emerging ones. An interdisciplinary workshop explored methods for country-level analysis of added value of One Health approaches to disease control. Key recommendations include: 1. systems thinking to identify risks and mitigation options for decision-making under uncertainty; 2. multisectoral economic impact assessment to identify wider relevance and possible resource-sharing, and 3. consistent integration of environmental considerations. Economic analysis offers a congruent measure of value complementing diverse impact metrics among sectors and contexts.

Surveillance strategies for Classical Swine Fever in wild boar - a comprehensive evaluation study to ensure powerful surveillance

Surveillance of Classical Swine Fever (CSF) should not only focus on livestock, but must also include wild boar. To prevent disease transmission into commercial pig herds, it is therefore vital to have knowledge about the disease status in wild boar. In the present study, we performed a comprehensive evaluation of alternative surveillance strategies for Classical Swine Fever (CSF) in wild boar and compared them with the currently implemented conventional approach. The evaluation protocol was designed using the EVA tool, a decision support tool to help in the development of an economic and epidemiological evaluation protocol for surveillance. To evaluate the effectiveness of the surveillance strategies, we investigated their sensitivity and timeliness. Acceptability was analysed and finally, the cost-effectiveness of the surveillance strategies was determined. We developed 69 surveillance strategies for comparative evaluation between the existing approach and the novel proposed strategies. Sampling only within sub-adults resulted in a better acceptability and timeliness than the currently implemented strategy. Strategies that were completely based on passive surveillance performance did not achieve the desired detection probability of 95%. In conclusion, the results of the study suggest that risk-based approaches can be an option to design more effective CSF surveillance strategies in wild boar.

A Blueprint to Evaluate One Health

One Health (OH) positions health professionals as agents for change and provides a platform to manage determinants of health that are often not comprehensively captured in medicine or public health alone. However, due to the organization of societies and disciplines, and the sectoral allocation of resources, the development of transdisciplinary approaches requires effort and perseverance. Therefore, there is a need to provide evidence on the added value of OH for governments, researchers, funding bodies, and stakeholders. This paper outlines a conceptual framework of what OH approaches can encompass and the added values they can provide. The framework was developed during a workshop conducted by the “Network for Evaluation of One Health,” an Action funded by the European Cooperation in Science and Technology. By systematically describing the various aspects of OH, we provide the basis for measuring and monitoring the integration of disciplines, sectors, and stakeholders in health initiatives. The framework identifies the social, economic, and environmental drivers leading to integrated approaches to health and illustrates how these evoke characteristic OH operations, i.e., thinking, planning, and working, and require supporting infrastructures to allow learning, sharing, and systemic organization. It also describes the OH outcomes (i.e., sustainability, health and welfare, interspecies equity and stewardship, effectiveness, and efficiency), which are not possible to obtain through sectoral approaches alone, and their alignment with aspects of sustainable development based on society, environment, and economy.

Application of discrete choice experiment to assess farmers' willingness to report swine diseases in the Red River Delta region, Vietnam

A discrete choice experiment (DCE) is carried out to value socio-economic factors influencing the farmer's decision to report swine diseases and to assess the willingness of farmers to report swine diseases. Data were collected between March and July 2015 in two provinces in the Red River Delta, Northern Vietnam, from 196 pig producers by face-to face interview. A conditional logit model is used to measure the relative importance of the socio-economic factors and calculate the expected probability of disease reporting under changes of levels of these factors. Results of the study indicated that the likelihood of compensation and the type of culling implemented (all or only unrecovered pigs) are the two most important factors influencing farmer reporting. Compensation level, movement restriction and delay in compensation payment also have significant impacts on farmer's decision to report animal disease but they are not as important as the above factors. Three different scenarios including changes in six different factors (attributes) are tested to predict probability of animal disease reporting. Under the current situation (uncertainty of being compensated), only 4% of the farmers would report swine disease outbreak to the official surveillance system if the culling policy involves all pigs in affected farms. This number is increased to 26% if culling in affected farms is restricted to unrecovered pigs only. Ensuring certainty of compensation increases reporting probability by up to 50% and 90% if all or only unrecovered pigs are destroyed, respectively. The results of this study are important for improving the performance and sustainability of swine disease surveillance system in Vietnam.

A chaotic model for the epidemic of Ebola virus disease in West Africa (2013-2016)

An epidemic of Ebola Virus Disease (EVD) broke out in Guinea in December 2013. It was only identified in March 2014 while it had already spread out in Liberia and Sierra Leone. The spill over of the disease became uncontrollable and the epidemic could not be stopped before 2016. The time evolution of this epidemic is revisited here with the global modeling technique which was designed to obtain the deterministic models from single time series. A generalized formulation of this technique for multivariate time series is introduced. It is applied to the epidemic of EVD in West Africa focusing on the period between March 2014 and January 2015, that is, before any detected signs of weakening. Data gathered by the World Health Organization, based on the official publications of the Ministries of Health of the three main countries involved in this epidemic, are considered in our analysis. Two observed time series are used: the daily numbers of infections and deaths. A four-dimensional model producing a very complex dynamical behavior is obtained. The model is tested in order to investigate its skills and drawbacks. Our global analysis clearly helps to distinguish three main stages during the epidemic. A characterization of the obtained attractor is also performed. In particular, the topology of the chaotic attractor is analyzed and a skeleton is obtained for its structure.

Hunters' acceptability of the surveillance system and alternative surveillance strategies for classical swine fever in wild boar - a participatory approach

BACKGROUND

Surveillance measures can only be effective if key players in the system accept them. Acceptability, which describes the willingness of persons to contribute, is often analyzed using participatory methods. Participatory epidemiology enables the active involvement of key players in the assessment of epidemiological issues. In the present study, we used a participatory method recently developed by CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement) to evaluate the functionality and acceptability of Classical Swine Fever (CSF) surveillance in wild boar in Germany, which is highly dependent on the participation of hunters. The acceptability of alternative surveillance strategies was also analyzed. By conducting focus group discussions, potential vulnerabilities in the system were detected and feasible alternative surveillance strategies identified.

RESULTS

Trust in the current surveillance system is high, whereas the acceptability of the operation of the system is medium. Analysis of the acceptability of alternative surveillance strategies showed how risk-based surveillance approaches can be combined to develop strategies that have sufficient support and functionality. Furthermore, some surveillance strategies were clearly rejected by the hunters. Thus, the implementation of such strategies may be difficult.

CONCLUSIONS

Participatory methods can be used to evaluate the functionality and acceptability of existing surveillance plans for CSF among hunters and to optimize plans regarding their chances of successful implementation.

Cultural Practices Shaping Zoonotic Diseases Surveillance: The Case of Highly Pathogenic Avian Influenza and Thailand Native Chicken Farmers

Effectiveness of current passive zoonotic disease surveillance systems is limited by the under-reporting of disease outbreaks in the domestic animal population. Evaluating the acceptability of passive surveillance and its economic, social and cultural determinants appears a critical step for improving it. A participatory rural appraisal was implemented in a rural subdistrict of Thailand. Focus group interviews were used to identify sanitary risks perceived by native chicken farmers and describe the structure of their value chain. Qualitative individual interviews with a large diversity of actors enabled to identify perceived costs and benefits associated with the reporting of HPAI suspicions to sanitary authorities. Besides, flows of information on HPAI suspected cases were assessed using network analysis, based on data collected through individual questionnaires. Results show that the presence of cockfighting activities in the area negatively affected the willingness of all chicken farmers and other actors to report suspected HPAI cases. The high financial and affective value of fighting cocks contradicted the HPAI control policy based on mass culling. However, the importance of product quality in the native chicken meat value chain and the free veterinary services and products delivered by veterinary officers had a positive impact on suspected case reporting. Besides, cockfighting practitioners had a significantly higher centrality than other actors in the information network and they facilitated the spatial diffusion of information. Social ties built in cockfighting activities and the shared purpose of protecting valuable cocks were at the basis of the diffusion of information and the informal collective management of diseases. Building bridges with this informal network would greatly improve the effectiveness of passive surveillance.

Applying participatory approaches in the evaluation of surveillance systems: A pilot study on African swine fever surveillance in Corsica

The implementation of regular and relevant evaluations of surveillance systems is critical in improving their effectiveness and their relevance whilst limiting their cost. The complex nature of these systems and the variable contexts in which they are implemented call for the development of flexible evaluation tools. Within this scope, participatory tools have been developed and implemented for the African swine fever (ASF) surveillance system in Corsica (France). The objectives of this pilot study were, firstly, to assess the applicability of participatory approaches within a developed environment involving various stakeholders and, secondly, to define and test methods developed to assess evaluation attributes. Two evaluation attributes were targeted: the acceptability of the surveillance system and its the non-monetary benefits. Individual semi-structured interviews and focus groups were implemented with representatives from every level of the system. Diagramming and scoring tools were used to assess the different elements that compose the definition of acceptability. A contingent valuation method, associated with proportional piling, was used to assess the non-monetary benefits, i.e., the value of sanitary information. Sixteen stakeholders were involved in the process, through 3 focus groups and 8 individual semi-structured interviews. Stakeholders were selected according to their role in the system and to their availability. Results highlighted a moderate acceptability of the system for farmers and hunters and a high acceptability for other representatives (e.g., private veterinarians, local laboratories). Out of the 5 farmers involved in assessing the non-monetary benefits, 3 were interested in sanitary information on ASF. The data collected via participatory approaches enable relevant recommendations to be made, based on the Corsican context, to improve the current surveillance system.

The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media.

When private actors matter: Information-sharing network and surveillance of Highly Pathogenic Avian Influenza in Vietnam

The effectiveness of animal health surveillance systems depends on their capacity to gather sanitary information from the animal production sector. In order to assess this capacity we analyzed the flow of sanitary information regarding Highly Pathogenic Avian Influenza (HPAI) suspicions in poultry in Vietnam. Participatory methods were applied to assess the type of actors and likelihood of information sharing between actors in case of HPAI suspicion in poultry. While the reporting of HPAI suspicions is mandatory, private actors had more access to information than public actors. Actors of the upstream sector (medicine and feed sellers) played a key role in the diffusion of information. The central role of these actors and the influence of the information flow on the adoption by poultry production stakeholders of behaviors limiting (e.g. prevention measures) or promoting disease transmission (e.g. increased animal movements) should be accounted for in the design of surveillance and control programs.

Analysis of Swine Movements in a Province in Northern Vietnam and Application in the Design of Surveillance Strategies for Infectious Diseases

While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a prerequisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta Province (northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades, that is between farms of equivalent sizes, whereas the other had pyramidal trades, that is from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that northern provinces were highly connected and showed some connection with central and southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector and to make recommendations for disease control.

Surveillance systems evaluation: a systematic review of the existing approaches

BACKGROUND

Regular and relevant evaluations of surveillance systems are essential to improve their performance and cost-effectiveness. With this in mind several organizations have developed evaluation approaches to facilitate the design and implementation of these evaluations.

METHODS

In order to identify and to compare the advantages and limitations of these approaches, we implemented a systematic review using the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

RESULTS

After applying exclusion criteria and identifying other additional documents via citations, 15 documents were retained. These were analysed to assess the field (public or animal health) and the type of surveillance systems targeted; the development process; the objectives; the evaluation process and its outputs; and the attributes covered. Most of the approaches identified were general and provided broad recommendations for evaluation. Several common steps in the evaluation process were identified: (i) defining the surveillance system under evaluation, (ii) designing the evaluation process, (iii) implementing the evaluation, and (iv) drawing conclusions and recommendations.

CONCLUSIONS

A lack of information regarding the identification and selection of methods and tools to assess the evaluation attributes was highlighted; as well as a lack of consideration of economic attributes and sociological aspects.

A rationale to unify measurements of effectiveness for animal health surveillance

Surveillance systems produce data which, once analysed and interpreted, support decisions regarding disease management. While several performance measures for surveillance are in use, no theoretical framework has been proposed yet with a rationale for defining and estimating effectiveness measures of surveillance systems in a generic way. An effective surveillance system is a system whose data collection, analysis and interpretation processes lead to decisions that are appropriate given the true disease status of the target population. Accordingly, we developed a framework accounting for sampling, testing and data interpretation processes, to depict in a probabilistic way the direction and magnitude of the discrepancy between "decisions that would be made if the true state of a population was known" and the "decisions that are actually made upon the analysis and interpretation of surveillance data". The proposed framework provides a theoretical basis for standardised quantitative evaluation of the effectiveness of surveillance systems. We illustrate such approaches using hypothetical surveillance systems aimed at monitoring the prevalence of an endemic disease and at detecting an emerging disease as early as possible and with an empirical case study on a passive surveillance system aiming at detecting cases of Highly Pathogenic Avian Influenza cases in Vietnamese poultry.