Nachlese zur internationalen Veranstaltung "Koi-Herpesvirus-Infektion" 2012

Programm für die internationale Veranstaltung vom 28. bis 30. März 2012 in Zwettl zum Thema "Koi-Herpesvirus-Infektion"

Seminarunterlagen zur Veranstaltung "Koi-Herpesvirus_Infektion" im März 2012 

"Fishproduction and Veterinary Fish-Health-Management in Austria" Heinz Heistinger (Österreichischer Beitrag)

Die Diagnostik der Koi-Herpesvirus-Infektion

Fischseuchenbekämpfung- Erfahrungen und Probleme bei der Umsetzung der RL 2006/88/EG unter besonderer Berücksichtigung der KHV-Infektion in Sachsen 

Report 
Andrea Höflechner-Pöltl, Gunnar Graber & Oskar Schachner

In several carp producing countries of Europe there are some objections to the practicability of the CD 2006/88/EC concerning the control of carp diseases, notably the KHV-Infection.

In order to articulate and discuss some of these objections 5 months ago, from 28th to 30th of March in Zwettl, in the middle of a Lower Austrian Carp farming area, a short meeting was arranged by the Austrian Federal Ministry of Health.

Purpose 

In some countries, until now outbreaks of KHV-I have been restricted to ornamental carps in garden ponds exclusively. For common carps produced for consumption the virus doesn’t appear as a severe problem there. For the traditional carp farming countries the actual legislation of KHV control measures and eradication according to the directive 2006/88/EC is inconsistent with the conservative near-natural method of carp production and contravenes with nature protection (and water management). Therefore the corresponding directive can’t be fully implemented. The regulated measures in case of an outbreak of disease as well as in case of an in-apparent KHV-infection are impossible to apply in spacious systems of connected ponds without extremely high economical and ecological losses.

At this meeting in Zwettl various representatives and stakeholders from carp farming countries and the representative of the EC should discuss and find common proposals for a more appropriate and applicable European legislation concerning the special target group of carp breeders and the control of KHV. Furthermore they should discuss issues concerning the global challenge of KHV control in ornamental fish trade as well as the diagnostic confusions around KHV, especially in clinically healthy fish.

Course of Action

The meeting has been attended by not less than 60 diverse stakeholder/representatives of 10 carp producing European countries; by carp breeders, by experts representing fish health administration, veterinary authorities, national as well as EU- and OIE- reference laboratories and last but not least by Sigrid Cabot representing the EC.

On March 29th veterinary representatives from 6 countries have reported actual data on the regional fish production and the status of KHV infection as well as the impact of KHV and the control measures in their respective countries.

With the exception of Hungary the virus has been detected in all countries already. The infection status of most carp farms is unknown. Referring to a colleague from Poland there are 13 396 farms of Category III and only 7 of Cat.I in whole Europe.

In the different countries there is evidence of different viral impact. The most considerable regional variety of KHV impact has been recorded from Germany, by opposing Bavaria to Saxony. Corresponding to the etiological impact attributed to KHV the efforts spent in the combat, eradication and control highly vary between the countries, being highest in Saxony.

Furthermore subject-specific presentations concerning fish farming, diagnostics, ornamental fish and legislation of KHV control have been given by experts. Last but not least Sigrid Cabot was talking about an Animal health strategy in consideration of carp breeding, themed "prevention is better than cure".

On the last day, March 30th, some of the problems and perspectives addressed have been discussed in 4 groups. Finally the results of the discussions have been summarized by the chairmen of each group.

Conclusions

The meeting contributed to a more complex understanding of the special conditions of carp farming and carp disease control. On the one hand the presentations pointed out the need of a more flexible legislation of KHV control measures, i.e. more consideration of regional conditions. On the other hand concerning the diagnostic tools for detection of virus and the surveillance of clinically healthy fish the demand of strict global harmonization has been claimed.

Corresponding to the different viral background and history in the respective countries, concerning the assessment of KHV-I in the list of notifiable diseases, different positions have been taken up. In most of the other issues full agreement could be achieved.

Concerning KHV control measures a more differentiated legislation has been claimed, taking into account the big differences between carp and trout farming as well as the regionally highly diverse environmental conditions of carp breeding.

Concerning ornamental fish and KHV prevention, minimal measures in case of a KHV-I-outbreak should be harmonized and implemented as should be the prevailing or adapted directives concerning trade and import. For all EU fish keepers importing animals from third countries, authorization and self control should be obligatory, and an official surveillance should be taken into consideration.

Concerning KHV diagnosis, again concordantly, an urgent demand came to expression:

For the detection of KHV in case of disease as well as for the confirmation of KHV-freedom in healthy fish the most reliable diagnostic procedure should be established and harmonized at global level. For both cases the recommended diagnostic tools are real-time PCR according to Gilad et al. (2004) and - for confirmation - a one-tube semi-nested PCR according to Bergmann et al. (2010). Organ samples tested for surveillance of clinically healthy fish populations should contain material of only two fish at the most.

The question concerning the cost-benefit balance of detecting as well as combating an inapparent infection remained open. Further questions and problems left open due to the lack of time:

The question concerning the use of serological methods for KHV detection and the question of Helle Frank Skall concerning the definition of KHV disease bearing in mind that some virus variants are not detectable by means of routinely used PCRs.

However not only questions remained open but there are also some hopeful perspectives:

Whereas Sigrid Cabot squashed hopes of fish trade restriction she commented on the conflict between EU harmonization and flexibility of member states by presenting an open box of general tools to increase awareness and preparedness concerning KHV-Infection:

The authorization and registration of farms, a good hygiene practice, traceability, animal health surveillance and the establishment of KHV zones.