Contents

2. Contents Rainbow Trout Production in Europe – trends Major Freshwater Diseases of Rainbow Trout in Europe –  What & where? Up or Down? ‘Ranking’? Conclusions?

3. France – decreased since 2001 (47500t) mainly due to poor prices. Also, fish being grown much bigger (better market price). Mostly pink. Italy – decreased since 2000 (45000t) mainly due to Lacto. 50:50 white:pink Turkey – increasing significantly. Virtually all white Denmark – fairly static production. Also export 200 million eggs and 100 million small trout. 22k white, rest pink. Spain – decreased since 2004 (34000t) mainly due to increasing Lacto & RTGE problems. Half of the eggs for export. 50:50 white:pink Germany? Not much egg production. Many eggs and fingerling imported from Denmark. UK – mostly static. Pink Eire 2600t Portugal 1500t. Pink. Austria 1800t, Czech 600t, Greece 3000t, Croatia 800t, Poland 14000t (increasing). All white.France – decreased since 2001 (47500t) mainly due to poor prices. Also, fish being grown much bigger (better market price). Mostly pink. Italy – decreased since 2000 (45000t) mainly due to Lacto. 50:50 white:pink Turkey – increasing significantly. Virtually all white Denmark – fairly static production. Also export 200 million eggs and 100 million small trout. 22k white, rest pink. Spain – decreased since 2004 (34000t) mainly due to increasing Lacto & RTGE problems. Half of the eggs for export. 50:50 white:pink Germany? Not much egg production. Many eggs and fingerling imported from Denmark. UK – mostly static. Pink Eire 2600t Portugal 1500t. Pink. Austria 1800t, Czech 600t, Greece 3000t, Croatia 800t, Poland 14000t (increasing). All white.

4. Norway produces very large trout (up to 5kg in some cases) Finland & Swedish production generally smaller – 1.2kg – 2kg Denmark – every single fish sold to Japan (mostly for roe). UK – seawater production of large trout expanding in last couple of years.Norway produces very large trout (up to 5kg in some cases) Finland & Swedish production generally smaller – 1.2kg – 2kg Denmark – every single fish sold to Japan (mostly for roe). UK – seawater production of large trout expanding in last couple of years.

5. Bacterial ERM – all countries except Norway* (Finland ? recently) (EX5) – UK, Eire, France, Norway, Finland, (other?) Furunculosis – all countries Vibriosis – Italy (fw) – Norway, Finland, Denmark, Spain, UK (sw) Lactococcosis – “warm-water” countries (Italy, Spain, France, Portugal, Turkey, Bulgaria, (UK)) RTFS – all countries (except Norway?) – now regularly affecting bigger fish RTGE – Spain, France, UK, (Italy?) Strawberry Disease – all countries? (not Dk or De) RMS – UK, (France, Spain, Finland) Switzerland? ERM - Recently has become an issue in Finland. Bacterium has been present in Finland for a long time but not causing problems. Now they have started to see mortality occurring in trout, zander & sturgeon. Trout from 50g – 3.5kg affected. No outbreaks in hatcheries or freshwater. Outbreaks are occurring in the Archipeligo sea (Baltic) which is brackish water. Problems mostly occurring at high water temps in the summer (15 – 20oC). University view is that the recent isolated strains appear to be different from the previous ones. They think that these strains are new to Finnish Aqua. Isolates differ when culturing them on agar. Strawberry Disease – diagnosed in Italy in 2006 & 2007 in NE region. Sporadic occurrence. Spain – sporadic & little impact at present RMS – France – a little but confused with Strawberry, Spain – sporadic & little impact, Finland – has been reported but no real impact, Switzerland – under suspicion…ERM - Recently has become an issue in Finland. Bacterium has been present in Finland for a long time but not causing problems. Now they have started to see mortality occurring in trout, zander & sturgeon. Trout from 50g – 3.5kg affected. No outbreaks in hatcheries or freshwater. Outbreaks are occurring in the Archipeligo sea (Baltic) which is brackish water. Problems mostly occurring at high water temps in the summer (15 – 20oC). University view is that the recent isolated strains appear to be different from the previous ones. They think that these strains are new to Finnish Aqua. Isolates differ when culturing them on agar. Strawberry Disease – diagnosed in Italy in 2006 & 2007 in NE region. Sporadic occurrence. Spain – sporadic & little impact at present RMS – France – a little but confused with Strawberry, Spain – sporadic & little impact, Finland – has been reported but no real impact, Switzerland – under suspicion…

6. Parasitic Whitespot – all countries PKD – UK & “southern” Europe Costia – all countries Trichodina – all countries Gyrodactylus/Dactylogyrus – all countries Argulus sp. – all countries

7. Viral Sleeping Disease (SD) – Spain, France, Germany, Italy, UK Viral Haemorrhagic Septicaemia (VHS) – all countries (?) (UK) Infectious Pancreatic Necrosis (IPN) – all countries Infectious Haematopoietic Necrosis (IHN) – Italy, France, Germany, Belgium, Spain, others? VHS – increasing problem in Italy year-on-year. Now a big issue. IHN – increasing problem in Ital year-on-year. Now a big issue.VHS – increasing problem in Italy year-on-year. Now a big issue. IHN – increasing problem in Ital year-on-year. Now a big issue.

8. Bacterial ERM = EX5 ?  Furunc ? Vibrio = Lacto ??? RTFS ?  RTGE ??  Strawberry ? RMS ? Parasitic Whitespot ???  PKD = Costia = Trich = Gyro’s = Argulus ??

9. ERM (EX5) Whitespot Lacto RTFS PKD RTGE Furunc Vibrio IPN RMS Strawberry SD VHS IHN (Argulus)

10. a new biogroup of Yersinia ruckeri 1993 – first isolation (Exmoor)1993-2001 – only 11 isolates (from 5 farms)2003 – outbreak on 1 farm in early spring (Feb) with farm-wide mortality2004 – 11 farms (geographically diverse) from February – September2005 – 16 farms2006 – 20 farms (representing over 50% of UK table trout production)2007 – 24 farms2008 – already a new site being tested…. EX5 is a Type 1 but with immunological similarities to Type V.EX5 is a Type 1 but with immunological similarities to Type V.

12. appears EX5 is more prevalent (or pathogenic?) at lower water temps than Hagerman Type I (outbreaks seen earlier in the year) affects all sizes of fish External Symptoms – same as Hagerman Type I (but fewer “black hangers” before morts start) Internal Symptoms– same as Hagerman Type I same gross colony morphology on plate, agglutinates with Mono-Yr kits, same antibiotic sensitivity profiles

13. Differential diagnosis –  API 20E identification profile – 5107100 positive for gelatin & Voges-Proskauer tests (this is differential for EX5) non-motile (Y. ruckeri usually motile) commercial vaccines seen to give a level of protection against EX5 but insufficient in some/most cases to avoid clinical symptoms and need for chemotherapy this has led to development of bivalent immersion vaccine – AquaVacTM RELERA N.B. Appears that injection vaccination with standard ERM vaccine affords 100% protection Tests to determine the production of catalase and oxidase, Gram reaction and motility were performed on the isolates. Serology (Bionor mono-Yr test kit) was done to assist in confirmation that the isolates were Yersinia ruckeri. The API 20E identification system was used to determine further phenotypic traits that are differential in distinguishing Y.ruckeri EX5-like biogroup isolates from the traditional Hagerman isolates. All of the strains gave a positive response for the production of catalase and a negative response for the production of oxidase. The isolates comprised medium-sized, Gram-negative rods with bipolar staining. All of the isolates were non-motile by microscopic examination using wet mounts. The strains showed positive agglutination against Y. ruckeri antiserum for the Bionor mono-Yr kits The identification profile obtained using the API 20E system was 5107100 for the six strains. The gelatin and Voges-Proskauer tests were positive. A positive response for these tests is differential for the EX5-like biogroup.Tests to determine the production of catalase and oxidase, Gram reaction and motility were performed on the isolates. Serology (Bionor mono-Yr test kit) was done to assist in confirmation that the isolates were Yersinia ruckeri. The API 20E identification system was used to determine further phenotypic traits that are differential in distinguishing Y.ruckeri EX5-like biogroup isolates from the traditional Hagerman isolates. All of the strains gave a positive response for the production of catalase and a negative response for the production of oxidase. The isolates comprised medium-sized, Gram-negative rods with bipolar staining. All of the isolates were non-motile by microscopic examination using wet mounts. The strains showed positive agglutination against Y. ruckeri antiserum for the Bionor mono-Yr kits The identification profile obtained using the API 20E system was 5107100 for the six strains. The gelatin and Voges-Proskauer tests were positive. A positive response for these tests is differential for the EX5-like biogroup.

14. Sampling program underway in other European countries….. So far positive isolates confirmed from – Eire (2005 – 1 site) France (2006 onwards – 19 isolates – geographically diverse) Norway (2006/7 – 1 salmon site – motile) Finland (1 isolate confirmed late 2007) Spain (under suspicion) What about other countries………?

16. Conclusions Trout LOTS of disease problems! Lactococcosis continues to be a HUGE problem in Italy & Spain RTFS continues to spread and is affecting bigger fish (and will get worse…..) Whitespot problems have increased and control is much more difficult Furunculosis is becoming more common Vaccination against ‘traditional’ bacterial diseases is effective (where done properly!)

17. Conclusions Trout ‘New’ disease problems are occurring and are rapidly becoming a serious issue in a number of countries – RTGE (BIG impact in Spain) Sleeping Disease RMS Strawberry Disease EX5 (on the ascendancy?) Will these ‘new’ trout problems move into salmon?