Strengthening diagnostic capacities and harmonising methods

The MedAID project (Mediterranean Aquaculture Integrated Development) aims to improve the key performance indicators (KPIs) of Mediterranean mariculture and considers health and welfare prerequisites for sustainable and profitable aquaculture in the Mediterranean area. Work-package 4: “Health management and diseases and fish welfare” addresses health issues and endeavours to provide tools and common strategies for the prevention and diagnosis of major diseases by creating an operative and collaborative Mediterranean platform. Task 4.2. “Strengthening diagnostic capacities by harmonising competences” focuses its objectives on i) The establishment of a network between all stakeholders included in diagnostics and health management, and ii) The evaluation of laboratory capacity and strengthening diagnostic capacity at national and regional level focusing on the most important pathogens.

Unlike freshwater and marine cold-water fish species, European sea bass and Gilthead sea bream diseases are not listed in the OIE aquatic code or in EU legislation, and there are no standards or guidelines for their control and for improving health. Thus, the first step to strengthen diagnostic capacities was to define the most relevant diseases that need improved diagnostics methodologies. The list of the most relevant diseases was created based on the results of several activities: i) the fish diseases survey organised by EURL addressed to a group of fish pathologists from the Mediterranean region. The survey consisted of a series of questions geared towards identifying and characterising the diseases of relevance for the regional aquaculture sector and mapping the health issues and infectious diseases in the area, ii) the working group discussions during the annual meeting of national reference laboratories for fish diseases organised to define the perception of the impact and risk of infectious fish diseases in Europe, iii) data collected during the “Workshop on animal health and risk analysis in finfish aquaculture” organised by FAO/GFCM, held in Larnaca, Cyprus, on 3-4 October 2018 where participants from Mediterranean countries presented the current status of diseases in their respective countries and iv) based on the results described in the MedAID Deliverable 1.2. “Assessment of the sustainability of Mediterranean aquaculture”. The results of these activities streamlined the selection of viral and bacterial diseases that need harmonised and improved diagnostic protocols.

MedAID partners prepared the “Diagnostic manual for the main pathogens in European sea bass and Gilthead sea bream aquaculture”. The diagnostic manual has been designed as a guideline providing detailed protocols for a sampling of fish on the farm, their packaging and shipping to the diagnostic laboratory and receipt of samples in the laboratory, followed by protocols for the diagnosis of the most prevalent diseases, such as Viral Nervous Necrosis (VNN), Vibriosis caused by V. anguillarum and V. harveyi, Photobacteriosis, the infection caused by Aeromonas spp., Tenacibaculum spp. and Mycobacterium spp., and the procedure to follow in cases of mortalities caused by unknown pathogens as well as instructions for reporting the diagnostic procedures. The Diagnostic Manual will be publicly available and designated for use in laboratories that need to improve or in newly established laboratories for the diagnosis of sea bass and sea bream diseases. Particular chapters were prepared by experts with experience in the diagnosis of certain diseases.

Thus, the chapter on VNN was prepared by the OIE reference laboratory for VNN/VER and they organised interlaboratory proficiency testing in order to validate the diagnostic procedure to detect and genotype NNV and to evaluate the diagnostic capacity of the participating laboratory. The results of the testing showed that there is room for improvement as some of the participants could not distinguish different genotypes of VNN.

In cooperation with PerformFISH, MedAID identified the laboratories dealing with diagnostics of sea bass and sea bream diseases throughout the Mediterranean basin including European (Italy, France, Spain, Greece, Portugal, Croatia and Slovenia) and non-European (Israel, Turkey, Algeria, Tunisia, Egypt and Morocco) countries. Using Google forms, a survey was carried out to evaluate the diagnostic capacities of fifty-two laboratories that agreed to fill in the survey. Interestingly, we found out that diagnostic capacities are not in tune with the amount of fish produced and that most of the specialised laboratories are located in Spain, Italy and France. The analysis of the survey results showed the differences between countries in the ability to diagnose a particular group of pathogens and established the route to take for improvement and strengthening.

The process of strengthening the diagnostic capacities started through activities such as the establishment of the MedAID Online Health Forum and by organising advanced training courses for professionals on Aquatic Animal Health. The forum is developed as a media platform for networking between farmers, stakeholders and experts. It was established basically to improve the collaboration and communication between industry, institutions and academics involved in sustainable health management, to enhance awareness of disease, to discuss and exchange experiences and knowledge, to promote collaboration on health issues, to answer questions on health problems in real time, to improve the ability to prevent, detect and constrain the particular health problem regionally, aiming to mitigate losses caused by the most devastating sea bass and sea bream pathogens. In the last year, three topics were discussed: 1) Sparicotylosis moderated by Ivona Mladineo, Institute of Oceanography and Fisheries, Split, Croatia; 2) VER/VNN moderated by Anna Toffan, IZSVE, OIE Reference laboratory for VER/VNN, Padova, Italy & Niccolo Vendramin, EURL for fish and crustacean diseases, DTU-Aqua, Lyngby, Denmark 3) Tenacibaculosis moderated by Alain LeBreton, SELARL Vet’Eau and Jean-Francois Bernardet, INRA, France. Many interesting experiences contributing to diagnostic issues and data on diseases management were shared in the discussion and more than 100 participants belonging to different bodies such as research and diagnostic institutions, consultancy services, pharmaceutical industries and farmers joined the forum. The forum will be continued with new discussions on topics pertaining to health management.

Two advanced training courses have been organised by the International Centre for Advanced Mediterranean Agronomic Studies (CIHEAM), through the Mediterranean Agronomic Institute of Zaragoza (IAMZ), under its regular programme, in collaboration with the project MedAID. Firstly, a course on the was held in Zaragoza (Spain) from 25 February to 1 March 2019 and secondly, a course on   is to be held in Zaragoza (Spain), from 21 to 25 October 2019, with the collaboration of the ParaFishControl and PerformFISH projects and of the University of Zaragoza. During the EAFP International Conference on Diseases of Fish and Shellfish in Porto from 08 to 12 September 2019, MedAID and their partners participating in ParaFishControl and PerformFISH are organising in the open workshop entitled ”The bottlenecks in diagnostics of Mediterranean fish diseases” where the working group discussion will try to find out how to harmonise the procedures recommended in the MedAID’s and ParaFishControl’s Diagnostic Manuals, and how to achieve their combination with meaningful field data at all levels.

The efficient network of diagnostic laboratories throughout the Mediterranean basin has been established and the future activities of Task 4.2. should be directed towards strengthening it. However, it is extremely important to maintain the sustainability of the network by establishing the focal point, which will moderate future activities.

Working group discussions during the annual meeting of National reference laboratories for fish diseases (Lyngby, DK, May 2018)


Snježana ZRNČIĆ, Senior Researcher
Croatian Veterinary Institute, Laboratory of fish, molluscs and crustacean diseases, Zagreb, Croatia.

WP 4 – Health management and diseases and fish welfare

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