Evaluating containment options for a Xylella outbreak in Andalusia through network analysis

The lack of data on pathogen spread complicates the fight against X. fastidiosa in Europe. Our previous work showed how the spatial arrangement of host plants can be used to elucidate management options in spite of such knowledge gaps; we generated networks of potential infection pathways from assumed vector dispersal ability and a map of olive orchards to assess the magnitude of the Xylella outbreak in Puglia. Here, we build on this technique to investigate scenarios of Xylella reaching Andalusia and causing OQDS. We compared the relative performance of two contrasting responses: 1) a preventive immunization strategy which encompasses different potential a priori measures to keep orchards uninfected, and 2) a quarantine strategy enacted at different stages of a hypothetical outbreak (a posteriori). Our results indicate that, from an epidemic perspective, preventive immunization is the best option to protect Andalusia from an OQDS epidemic. A posteriori quarantine action can only be successful if it is rigorously implemented at the first infection event; it should be applied to all hosts within the vector’s maximum flight distance and before any quarantined node has become infectious, thus requiring a reliable early detection program. We evaluate how the efficacy of quarantine changes as the epidemic progresses, and how it compares to preventive immunization as well as to non-intervention. We discuss the relevance of our findings for OQDS prevention on mainland Spain.

STRONA Giovanni;  CASTELLANO Claudio;  FATTORINI Simone; 

BECK Pieter; 

2018-06-14

EFSA

JRC109803

http://www.efsa.europa.eu/en/events/event/171113,    https://publications.jrc.ec.europa.eu/repository/handle/JRC109803,