**Challenges of Engaging Actors via a Co-Design Process: The Case of the PREZODE (Preventing Zoonotic Disease Emergence) International Initiative**

**H. Ladreyt, M. Olive, M. Peyre, N. Rousseau, M. Lounas, C. Grimaldi, B. Roche, G. Vourc'h, E. Bohin, M. Trouillet, JF. Soussana, P. Dussort, V. Lecointe, G. Blandin, S. Signoret, and the PREZODE consortium**

The PREZODE (preventing zoonotic disease emergence) initiative aims to catalyze joint actions in order to improve surveillance, risk mitigation, and early warning systems for zoonotic emergencies, adapted to local socio-economic contexts in co-construction with local actors and decision-makers, especially in high-risk areas. A strong ambition of PREZODE is to be co-designed with all relevant stakeholders, between health sectors (animal, human, and environment), researchers, field operators, decision-makers, and between private and public sector actors, from local to international levels. This co-design process must allow, on the one hand, to define the generic scientific and operational framework of the initiative, adapted to all regions of the world, but also the specific modalities of its implementation in each region to prevent zoonotic disease emergence. From June to November 2021, a series of online regional iterative workshops following a standardized participatory method were implemented to 1) define and share a common vision of the initiative, its main objectives, expected impacts, and potential obstacles, 2) identify all the relevant actors and the changes in practices needed to ensure adoption of risk reduction and prevention solutions, 3) identify the activities to be implemented to promote such changes and develop innovations, from local to national, regional, and then global, and 4) to identify the research gaps and cutting edge in science to reach a low level of zoonotic emergence. The data generated from the workshops were literally transcribed and analyzed, accounting for biases of participation and representativeness linked to this large-scale and online co-design process. In addition, a structured questionnaire was sent to all workshop participants to assess their interest in this innovative process and to evaluate its strengths, weaknesses, and usefulness in the co-design of PREZODE. Three phases of nine regional workshops (West Africa, Austral and East Africa, Central Africa, North Africa and Mediterranean, Southeast Asia, Indian Ocean, Latin America and Caribbean, Europe, and USA) were then carried out, and gathered more than 1000 contributors from 130 countries, from academic/research (59%) but also policy fields (27%), operational (8%), and private sectors (6%). The global common vision of PREZODE was expressed as "a world without pandemics, where food safety, environmental protection, surveillance of zoonoses emergence and community inclusion is ensured by taking into account the inclusion of communities in a local to global approach". A total of 39 main obstacles to reaching the regional common vision were sorted into 19 categories of main obstacles, and 462 root obstacles were sorted into 101 categories of root obstacles. Nine categories of main obstacles cut across several regions, including lack of intersectorality and interdisciplinarity, economic issues, political issues, and socio-cultural issues. In addition, several categories of root obstacles cut across several main obstacles, such as education and training issues, lack of bottom-up approaches, and community inclusion, which therefore seem appropriate to work on first in order to unblock sets of main obstacles. All the elements generated during this co-design process will allow identifying operational actions and research questions to develop the PREZODE scientific strategic agenda, which will be validated by all the workshop participants, experts, and decision- makers. This agenda will allow us to define the most relevant activities to be implemented in the next 30 years to prevent disease emergence risks.

Co-design process methodology = federate and bring people around the table to deconstruct and reconstruct the problem together ➔ actors' engagement in the initiative.

**More precisely, participants agreed on the need to…**


#### **…in order to better prevent zoonotic diseases emergence.**

Next, participants identified change needs, solutions, and activities to achieve these goals, which are currently being analyzed to identify research, operational, policy, and capacity needs.

#### Authors

H. Ladreyt, M. Olive, M. Peyre, N. Rousseau, M. Lounas, C. Grimaldi, B. Roche, G. Vourc'h, E. Bohin, M. Trouillet, JF. Soussana, P. Dussort, V. Lecointe, G. Blandin, S. Signoret, and the PREZODE consortium.

#### Background

The PREZODE (for Preventing ZOonotic Disease Emergence) initiative aims to catalyze joint actions in order to improve surveillance, risk mitigation and early warning systems for zoonotic emergence, adapted to local socio-economic contexts in co- construction with local actors and decision-makers, especially in highrisk areas. A strong ambition of PREZODE is for it to be co-designed with all relevant stakeholders, between health sectors (animal, human and environment), researchers, field operators, and decision-makers and between private and public sector actors from local to international levels. This co-design process must allow the generic scientific and operational framework of the initiative to be defined and adapted to all regions of the world, and also for the specific modalities of its implementation in each region to also be defined to prevent zoonotic disease emergence.

#### Materials and Methods Results and Participation

#### Results: Vision and Outputs

"a world without pandemics, where food safety, environmental protection, surveillance of zoonoses emergence and community inclusion is ensured by taking into account the inclusion of communities in a local to global approach"

#### Discussion and Perspectives

The long process with many steps:

\*impatience of participants to see the result of their involvement strong need for feedback and communication;

\*lots of data to be analyzed (>6000 ideas exchanged), which can be heterogeneous strong need for briefing and support for workshop facilitators.

➔Bring the process to the national level to reinforce actors' engagement and to specify research gaps and operational needs at a lower scale.

➔Research, operational, policy, and capacity needs will be listed in the PREZODE scientific strategic agenda (to be released fall 2022), which will be validated by all the workshop participants, experts, and decision makers. This agenda will allow the identification of the most relevant activities to be implemented in the next 30 years to prevent disease emergence risks.

**interested** Challenge of the process: The PREZODE team would like to warmly thank all the participants in the co-construction workshops for their time and their involvement in the process.

**PREZODE COMMON VISION**

Challenges of Engaging Actors via a Co-Design Process: The Case of the PREZODE (Preventing Zoonotic Disease Emergence) International Initiative

## **Modeling Japanese Encephalitis Virus Transmission Dynamics and Human Exposure in a Rural Cambodian Multi-Host System**

**Héléna Ladreyt1, Véronique Chevalier1, 2, 3, and Benoit Durand4**

1CIRAD, UMR ASTRE, Montpellier, France

2CIRAD, UMR ASTRE, 101, Antananarivo, Madagascar

<sup>3</sup> Institut Pasteur of Madagascar, Epidemiology and Clinical Research Unit, Antananarivo, Madagascar

4Epidemiology Unit, Laboratory for Animal Health, ANSES, Maisons-Alfort, France

Japanese encephalitis (JE) is a vector-borne zoonosis and the leading cause of acute human encephalitis in Asia. Its epidemiological cycle is usually described as involving wild birds as reservoirs and pigs as amplifying hosts. JE is endemic in Cambodia, where it circulates in areas with low pig densities and could be maintained in a multi-host system composed of pigs but also poultry as competent hosts and dogs, cattle, and humans as non-competent hosts. We developed a mathematical model representing Japanese encephalitis virus (JEV) transmission in a traditional Cambodian village (calibrated with field data collected in three districts of Kandal province) to assess the capacity of the epidemiological system to sustain JEV transmission in villages in the three districts (based on R0), and to quantify human exposure. Changes in farm density and agricultural practices, climate, or epizootics (e.g., African swine fever), can profoundly alter the composition of host communities, which could affect JEV transmission and its impact on human health: we used the model to analyze how host community composition affected R0 and human exposure. Lastly, we evaluated the potential use of dog JE seroprevalence as an indicator of human exposure to JEV. In the modeled villages, the calculated R0 ranged from 1.07 to 1.38. The predicted annual probability of human exposure ranged from 9% to 47% and the predicted average age at infection was low, between 2 and 11 years old, highlighting the risk of severe forms of JEV infection and the need to intensify child immunization. According to the model, increasing the proportion of competent hosts induced a decrease in age at infection, thus the potential clinical impact on children's health. The simulations also showed that JEV could invade a pig-free multi-host system, suggesting that poultry might act as reservoirs. Finally, the annual human exposure probability appeared linearly correlated with dog seroprevalence, suggesting that in our specific study area, dog seroprevalence would be a good proxy for human exposure.

R0 is princially influenced by the proportion of pigs in the system. Scenario B, **0 pigs : IC95% R0 includes 1** !

Results In a traditional village of Kandal province:


Village/multi-host system composition modification:

#### Dog seroprevalence as a proxy for human exposure?

#### Discussion and Perspectives

\*First JEV model calibrated on field data in Cambodia that suggest a quantification of human exposure;

\*Poultry potential reservoir of JEV;

\*Estimated incidence of infection in Kandal: 14 infections for 1000 habitants/year;

\*Clinical cases incidence? : 1/500 to 1/250 of infections would be symptomatic (hospital-based data).

➔3/100 000 to 6/100 000 clinical cases/years in Kandal.

Average age at infection low ➔ severe cases ➔ intensify vaccination of children in Cambodia

Annual probability of human exposure to JEV according to dog JEV seroprevalence.

#### Authors

Héléna Ladreyt1, Véronique Chevalier1,2,3,4, and Benoit Durand5


### Background

Japanese encephalitis (JE) is a vector-borne zoonosis and the leading cause of human acute encephalitis in Asia. Its epidemiological cycle is usually described as involving wild birds as reservoirs, pigs as amplifying hosts and Culex spp mosquitoes as vectors. JE is endemic in Cambodia, where it circulates in areas with low pig densities and could be maintained in a multi- host system composed of pigs, but also involves poultry as competent hosts and dogs, cattle and humans as noncompetent hosts.


### Materials and Methods
