Call for Data: Length of Incubation Periods of Xylella fastidiosa Subspecies in Infected Plants

EFSA-Q-number: EFSA-Q-2024-00322
Deadline for Call for Expression of Interest: 30/04/2025
Deadline for submission of data: 31/05/2025

Background

EFSA is requested, pursuant to Article 29 of Regulation (EC) No 178/2002, to provide a scientific opinion. In particular, EFSA is requested to update the Scientific Opinion on the risks to plant health posed by Xylella fastidiosa in the EU territory published on 15 May 2019.

To address the mandate and model the infectious disease dynamics of Xylella fastidiosa, EFSA is reviewing the scientific literature to characterise quantitatively:

• The Incubation Period for Acquisition (IPA): time from X. fastidiosa inoculation to when the infection becomes systemic and/or a source of inoculum (i.e., when vectors can acquire the bacterium from it).
• The Incubation Period for Symptoms (IPS): time from inoculation with the bacterium to the emergence of the symptoms in the host plant.

Studies specifically designed to characterize these parameters are scarce in the existing scientific literature. 

The IPA can be practically interpreted as the time from  Xylella fastidiosa inoculation by the vector or artificial mechanical inoculation of the plant to when the plant becomes systemically infected and becomes a source of  Xylella fastidiosa for the vector, i.e. the bacterium can be acquired by the vector.

This parameter is particularly challenging to quantify as it is influenced by multiple factors, such as the heterogeneous distribution and population of the bacterium within the infected plant, both of which evolve dynamically throughout the course of the infection. Nonetheless, data from vector acquisition and transmission experiments reporting bacterial population over time in artificially infected plants might be useful to approximate when bacterial levels become high enough and systemically spread to enable successful acquisition by the vector.

Data on the IPS can be extrapolated, for example, from experimental studies investigating the susceptibility of plants to  Xylella fastidiosa persistent systemic infection or the successful acquisition of the bacterium by insect vectors. In fact, these studies typically involve the regular monitoring of naturally or artificially infected plants over time and might include the recording of the time until symptoms emergence.

To ensure a comprehensive assessment, EFSA launches a public call for all potentially relevant available data (published, unpublished or newly generated data) from interested parties. EFSA will then consider the relevance of the information provided for the risk assessment. The submission of the requested information is without prejudice to the final opinion of the PLH Panel.

Overall objective

Data sought and data submission format

To ensure the relevance and quality of the data submitted, studies or data should fulfil a set of predefined criteria. These criteria are designed to ensure that the information can effectively contribute to the assessment:

Documentation and Traceability: Submitted studies must be well-documented, including a detailed descriptions of methodology with particular reference to the methods used for detection and isolation of the bacteria, the experimental conditions, and data collection protocols.

Relevance to the Parameters: The data should explicitly address or provide sufficient information to infer the latent period and/or incubation period of Xylella fastidiosa, ideally, the subspecies is specified.

Consistency and Reliability: Data should originate from scientifically robust studies, with consistent observations and clearly defined timeframes for monitoring infection or acquisition processes.

EFSA kindly invites interested parties to submit information as outlined below.
To submit data, please provide the documentation of the study exemplifying the above criteria. Results should be provided in tabular format (e.g., Excel). Any additional data (e.g. Symptom images) are welcome.

Should you require assistance when filling in the Excel file for analytical data/use levels or have specific questions on how to send the data, please contact RAL [at] efsa.europa.eu (RAL[at]efsa[dot]europa[dot]eu) .

Deadline for submission of interest via EU survey

Interested parties and stakeholders should express their interest to submit data via EU Survey tool by 30/04/2025.

EU Survey Expression of interest to provide data for Call for Data on Xylella

Deadline for submission of data

Parties and stakeholders should submit data by 31/05/2025.

Confidentiality

In order to comply with its requirements for proactive transparency, EFSA must, inter alia, make public the information on which its scientific outputs are based, as outlined in Article 38(1)(d) of Regulation (EC) No 178/2002, the “General Food Law” (GFL) and Article 6(1)(i) of EFSA’s Practical Arrangements concerning transparency and confidentiality (“EFSA’s Practical Arrangements”). Information/data received in the context of the present call are subject to the afore-mentioned proactive transparency requirements insofar as they will constitute information on which scientific outputs, including scientific opinions, are based. 

However, in accordance with Articles 39-39e of the GFL confidential status may be awarded to information the disclosure of which might potentially harm the information owner to a significant degree. Provided that the conditions set out in Articles 39-39e and further detailed in EFSA’s Practical Arrangements are satisfied, EFSA must not make public any information/data for which confidential treatment has been requested and duly justified pending its confidentiality assessment where urgent action is essential to protect human health, animal health or the environment. 

Submission of data

Interested business operators and/or parties should submit the information/data in electronic format exclusively via the tool Submission Builder “Portalino” (available here).

Submission of data in any other form (email, third party e-submission platforms, etc) will not be accepted. 

Information on how to use Portalino and submit confidentiality requests are available online here. Information on how to use Portalino and submit confidentiality requests is available here. Information regarding confidentiality can be found in the User Guide on Confidentiality. 

Interested business operators and/or interested parties should submit the following information to EFSA via Portalino, clearly stating: 

• in the Subject of the submission: Call for data on Xylella incubation period EFSA-Q-2024-00322
• The contact details (name of contact person, name of company/organisation, e-mail address and telephone number) of the person responsible for the data submission and, if applicable, the list of interested business operators and/or interested parties represented and their contact details.

When sharing information/data with EFSA, certain parts of the information/data may be requested to be treated as confidential provided that:

i. the information falls within the scope of the closed list of information items listed in the Annex to EFSA’s Practical Arrangements and

ii. the confidentiality request is accompanied by a verifiable justification that demonstrates how the public disclosure of the information/data for which confidential status is requested would harm your interests to a significant degree. 

iii. When claiming confidentiality for some of the information/data, both a non-confidential (public dissemination) and a confidential version of the information/data must be submitted as indicated here. A separate confidentiality request must be submitted for each document and for each legal ground under which information is claimed confidential. A precise description of the information/data claimed confidential must be provided to enable a clear identification and the information/data claimed confidential must be earmarked in the confidential version and redacted in the non-confidential version.

For submissions which do not contain any confidential information, only a non-confidential (public dissemination) version has to be uploaded to Portalino.

Please note that EFSA may, where legally possible, use or re-use relevant information or data (e.g., technical, toxicological data) for the assessment of the same or another substance/topic under the same or a different legal or regulatory framework from the one mentioned above.