• Aucun résultat trouvé

Important notes:

N/A
N/A
Protected

Academic year: 2021

Partager "Important notes:"

Copied!
2
0
0

Texte intégral

(1)

Important notes:

Do NOT write outside the grey boxes. Any text or images outside the boxes will be deleted.

Do NOT alter the structure of this form. Simply enter your information into the boxes. The form will be automatically processed – if you alter its structure your submission will not be processed correctly.

Do not include keywords – you can add them when you submit the abstract online.

Title:

Speed of Bluetongue Epizootic Wave in France during the 2006-2008 Outbreak

Authors & affiliations:

M. Pioz*1, 2, H. Guis2, D. Calavas3, B. Durand3, L. Crespin1, Gay E3., Abrial D1., C. Ducrot1

1

French National Institute for Agricultural Research, France; 2 French Agricultural Research Center for International Development (CIRAD), France; 3 French Agency for Food, Environmental and Occupational Health and Safety, France

[email protected]

Abstract: (Your abstract must use Normal style and must fit in this box. Your abstract should be no longer than 300 words. The box will ‘expand’ over 2 pages as you add text/diagrams into it.)

In 2006-2009 northwest Europe experienced a major Bluetongue outbreak, an infectious disease of ruminants transmitted by biting midges belonging to the genus

Culicoides. Bluetongue Virus, the causal agent, was introduced near Maastricht in

the Netherlands, close to the borders with Germany and Belgium, in summer 2006. Bluetongue spread rapidly, infecting 2,000 farms across Belgium, Germany, the Netherlands, France and Luxembourg in 2006, and more than 30,000 farms in 2007 reaching Denmark, the United Kingdom, Switzerland, and the Czech Republic. By the end of 2009, Bluetongue had spread to most of the countries in northwest Europe.

France was particularly impacted by the disease in 2007-2008. We explored the spatial dynamics of Bluetongue to understand where and how fast the disease spread. Using a trend-surface analysis model combined with a spatial error simultaneous autoregressive model, we estimated the speed of the Bluetongue epidemic wave based on clinical cases in France in 2007-2008. Overall, Bluetongue spread from north-eastern to south-western France with an average estimated velocity of 5.6 km/day. However, the diffusion was not homogeneous, and the velocities differed between areas and time periods, varying between 2.1 and 9.3 km/day. To understand what has influenced the speed of spread across the country, we also investigated the effect of environmental conditions on the estimated velocities. We specifically studied the effect of host density, host vaccination, landscape pattern, and lagged meteorological conditions as a proxy of vector abundance and activity.

Our study showed that Bluetongue spread in France was primarily local, consistent with the active flight of Culicoides and local movements of farm animals. Beside the expected effect of host density and vaccination on Bluetongue spread, we

highlighted the effect of landscape pattern and 2-month lagged meteorological conditions as major factors influencing the velocity of the epizootic wave.

(2)

Important notes:

Do NOT write outside the grey boxes. Any text or images outside the boxes will be deleted.

Do NOT alter the structure of this form. Simply enter your information into the boxes. The form will be automatically processed – if you alter its structure your submission will not be processed correctly.

Do not include keywords – you can add them when you submit the abstract online.

EPIDEMICS3 - Third International Conference on Infectious Disease Dynamics 29th November – 2nd December 2011, Boston, MA, USA

Références

Documents relatifs

This observation is interpreted as follows: on the one hand, time delays corresponding to the downstream causality are associated with over-accumulation of water in upper regions

We illustrate an approach using a trend-surface analysis (TSA) model combined with a spatial error simultaneous autoregressive model (SAR err model) to estimate the speed of

Indeed, due to its construction, this estimator is expected to have good properties when the stationary distribution of the Markov Chain is close to the Gaussian distribution.. On

The main drawback of their approach is that their estimation criterion is not explicit, hence the links between the convergence rate of their estimator and the smoothness of

On the other hand, one needs additional information on the infection fatality ratio (i.e., the proportion of infected individuals who die eventually) and on the distribution of

This paper investigates the lag length selection problem of a Vector Error Correction Model (VECM) by using a convergent information criterion and tools based on the

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des

(9) The sign of the bistable wave speed indicates the propagation direction of the bistable trav- elling wave solution.. Hence it predicts which stable state has an advantage