Infection with Gyrodactylus salaris

Article 10.3.1.

For the purposes of the Aquatic Code, gyrodactylosis means infection with the viviparous freshwater ectoparasite G. salaris (G. salaris) (Phylum Platyhelminthes; Class Monogenea).

Information on methods for diagnosis are provided in the Aquatic Manual.

Article 10.3.2.

Scope

The recommendations in this chapter apply to: Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), Arctic char (Salvelinus alpinus), North American brook trout (Salvelinus fontinalis), grayling (Thymallus thymallus), North American lake trout (Salvelinus namaycush) and brown trout (Salmo trutta). The recommendations also apply to other fish species in waters where the parasite is present, because these species may carry the parasite and act as vectors.

Article 10.3.3.

Importation or transit of aquatic animals and aquatic animal products for any purpose from a country, zone or compartment not declared free from infection with G. salaris

1. Competent Authorities should not require any related conditions related to infection with G. salaris, regardless of the infection with G. salaris status of the exporting country, zone or compartment, when authorising the importation or transit of the following aquatic animals and aquatic animal products from the species referred to in Article 10.3.2. which are intended for any purpose and which comply with Article 5.4.1.:

   1. heat sterilised, hermetically sealed fish products (i.e. a heat treatment at 121˚C for at least 3.6 minutes or any time/temperature equivalent);

   2. pasteurised fish products that have been subjected to a heat treatment at 63˚C for at least 30 minutes (or any time/temperature equivalent which has been demonstrated to inactivate G. salaris);

   3. mechanically dried, eviscerated fish (i.e. a heat treatment at 100˚C for at least 30 minutes or any time/temperature equivalent which has been demonstrated to inactivate G. salaris);

   4. naturally dried, eviscerated fish (i.e. sun-dried or wind-dried);

   5. frozen eviscerated fish that have been subjected to minus 18°C or lower temperatures;

   6. frozen fish fillets or steaks that have been subjected to minus 18°C or lower temperatures;

   7. chilled eviscerated fish that have been harvested from seawater with a salinity of at least 25  parts per thousand (ppt);

   8. chilled fish fillets or steaks derived from fish that have been harvested from seawater with a salinity of at least 25 ppt;

   9. chilled fish products from which the skin, fins and gills have been removed;

   10. fish roe;

   11. fish oil;

   12. fish meal;

   13. fish skin leather.

2. When authorising the importation or transit of aquatic animals and aquatic animal products of a species referred to in Article 10.3.2., other than those referred to in point 1 of Article 10.3.3., Competent Authorities should require the conditions prescribed in Articles 10.3.7. to 10.3.11. relevant to the infection with G. salaris status of the exporting country, zone or compartment.

3. When considering the importation or transit of aquatic animals and aquatic animal products of a species not covered in Article 10.3.2. but which could reasonably be expected to pose a risk of spread of infection with G. salaris, the Competent Authority should conduct a risk analysis in accordance with the recommendations in Chapter 2.1. The Competent Authority of theexporting country should be informed of the outcome of this assessment.

Article 10.3.4.

Country free from infection with G. salaris

If a country shares a zone with one or more other countries, it can only make a self-declaration of freedom from infection with G. salaris if all the areas covered by the shared watercourse(s) are declared countries or zones free from infection with G. salaris (see Article 10.3.5.).

As described in Article 1.4.6., a country may make a self-declaration of freedom from infection with G. salaris if:

1. none of the susceptible species referred to in Article 10.3.2. are present and basic biosecurity conditions have been continuously met for at least the last two years;

OR

2. any of the susceptible species referred to in Article 10.3.2. are present and the following conditions have been met:

   1. there has been no observed occurrence of the disease for at least the last ten years despite conditions that are conducive to its clinical expression (as described in the corresponding chapter of the Aquatic Manual); and

   2. basic biosecurity conditions have been continuously met for at least the last ten years;

OR

3. the disease status prior to targeted surveillance is unknown but the following conditions have been met:

   1. basic biosecurity conditions have been continuously met for at least the last five years; and

   2. targeted surveillance, as described in Chapter 1.4., has been in place for at least the last five years without detection of infection with G. salaris;

OR

4. it previously made a self-declaration of freedom from infection with G. salaris and subsequently lost its disease free status due to the detection of infection with G. salaris but the following conditions have been met:

   1. on detection of the disease, the affected area was declared an infected zone and a protection zone was established; and

   2. infected populations have been destroyed or removed from the infected zone by means that minimise the risk of further spread of the disease, and the appropriate disinfection procedures (as described in the Aquatic Manual) have been completed, or the waters containing the infected fish have been treated by chemicals that kill the parasite; and

   3. previously existing basic biosecurity conditions have been reviewed and modified as necessary and have continuously been in place since eradication of the disease; and

   4. targeted surveillance, as described in Chapter 1.4., has been in place for at least the last five years without detection of infection with G. salaris.

   In the meantime, part or all of the non-affected area may be declared a free zone provided that such a part meets the conditions in point 3 of Article 10.3.5.

Article 10.3.5.

Zone or compartment free from infection with G. salaris

If a zone or compartment extends over more than one country, it can only be declared a zone or compartment free from infection with G. salaris if all the relevant Competent Authorities confirm that all relevant conditions have been met.

As described in Article 1.4.6., a zone or compartment within the territory of one or more countries not declared free from infection with G. salaris may be declared free by the Competent Authority(ies) of the country(ies) concerned if:

1. none of the susceptible species referred to in Article 10.3.2. are present in the zone or compartment and basic biosecurity conditions have been continuously met for at least the last two years;

OR

2. any of the susceptible species referred to in Article 10.3.2. are present in the zone or compartment and the following conditions have been met:

   1. there has been no observed occurrence of the disease for at least the last ten years despite conditions that are conducive to its clinical expression (as described in the corresponding chapter of the Aquatic Manual); and

   2. basic biosecurity conditions have been continuously met for at least the last five years;

OR

3. a zone or compartment supplied with seawater with a salinity of at least 25 ppt may be declared free from infection with G. salaris provided that no live aquatic animals of species referred to in Article 10.3.2. are introduced from a site of a lesser health status for G. salaris during the 14 days prior to any live fish transfers from the zone or compartment;

OR

4. the disease status prior to targeted surveillance is unknown but the following conditions have been met:

   1. basic biosecurity conditions have been continuously met for at least the last ten years; and

   2. targeted surveillance, as described in Chapter 1.4., has been in place, in the zone or compartment, for at least the last five years without detection of infection with G. salaris;

OR

5. it previously made a self-declaration of freedom for a zone from infection with G. salaris and subsequently lost its disease free status due to the detection of infection with G. salaris in the zone but the following conditions have been met:

   1. on detection of the disease, the affected area was declared an infected zone and a protection zone was established; and

   2. infected populations have been destroyed or removed from the infected zone by means that minimise the risk of further spread of the disease, and the appropriate disinfection procedures (as described in the Aquatic Manual) have been completed, or the waters containing the infected fish have been treated by chemicals that kill the parasite; and

   3. infected populations have been destroyed or removed from the infected zone by means that minimise the risk of further spread of the disease, and the appropriate disinfection procedures (as described in the Aquatic Manual) have been completed, or the waters containing the infected fish have been treated by chemicals that kill the parasite; and

   4. targeted surveillance, as described in Chapter 1.4., has been in place for at least the last five years without detection of infection with G. salaris.

Article 10.3.6.

Maintenance of free status

A country, zone or compartment that is declared free from infection with G. salaris following the provisions of points 1 or 2 of Articles  10.3.4. or 10.3.5. (as relevant) may maintain its status as free from infection with G. salaris provided that basic biosecurity conditions are continuously maintained.

A country, zone or compartment that is declared free from infection with G. salaris following the provisions of point 3 of Article 10.3.4. or point 4 of 10.3.5. (as relevant) may discontinue targeted surveillance and maintain its status as free from infection with G. salaris provided that conditions that are conducive to clinical expression of infection with G. salaris, as described in the corresponding chapter of the Aquatic Manual, exist, and basic biosecurity conditions are continuously maintained.

However, for declared free zones or compartments in infected countries and in all cases where conditions are not conducive to clinical expression of infection with G. salaris, targeted surveillance needs to be continued at a level determined by the Aquatic Animal Health Service on the basis of the likelihood of infection.

Article 10.3.7.

Importation of aquatic animals and aquatic animal products from a country, zone or compartment declared free from infection with G. salaris

When importing aquatic animals and aquatic animal products of species referred to in Article 10.3.2. from a country, zone or compartment declared free from infection with G. salaris, the Competent Authority of the importing country should require that the consignment be accompanied by an international aquatic animal health certificate issued by the Competent Authority of the exporting country or a certifying official approved by the importing country certifying that, on the basis of the procedures described in Articles 10.3.4. or 10.3.5. (as applicable) and 10.3.6., the place of production of the aquatic animals and aquatic animal products is a country, zone or compartment declared free from infection with G. salaris.

The certificate should be in accordance with the Model Certificate in Chapter 5.11.

This Article does not apply to commodities referred to in point 1 of Article 10.3.3.

Article 10.3.8.

Importation of live aquatic animals for aquaculture from a country, zone or compartment not declared free from infection with G. salaris

1. When importing, for aquaculture, live aquatic animals of species referred to in Article 10.3.2. from a country, zone or compartment not declared free from infection with G. salaris, the Competent Authority of the importing country should:

   1. require an international aquatic animal health certificate issued by the Competent Authority of the exporting country attesting that:

      1. the aquatic animals have been held, immediately prior to export, in water with a salinity of at least 25 parts per thousand for a continuous period of at least 14 days; and

      2. no other live aquatic animals of the species referred to in Article 10.3.2. have been introduced during that period;

      OR

      3. in the case of eyed eggs, the eggs have been disinfected by a method demonstrated to be effective against G. salaris;

   OR

   2. assess the risk and apply risk mitigation measures such as:

      1. the direct delivery to and lifelong holding of the consignment in biosecure facilities for continuous isolation from the local environment;

      2. if breeding from the imported fish, disinfection of the fertilised eggs by a method demonstrated to be effective against G. salaris, and complete separation of the hatched progeny from the imported animals;

      3. the treatment of water used in transport and of all effluent and waste materials in a manner that ensures inactivation of G. salaris.

2. If the intention of the introduction is the establishment of a new stock, relevant aspects of the Code of Practice on the Introductions and Transfers of Marine Organisms of the International Council for the Exploration of the Seas (ICES) should be followed.

3. For the purposes of the Aquatic Code, relevant aspects of the ICES Code (full version see: http://www.ices.dk/publications/our-publications/Pages/Miscellaneous.aspx) may be summarised to the following points:

   1. identify stock of interest (cultured or wild) in its current location;

   2. evaluate stock’s health and disease history;

   3. take and test samples for G. salaris, pests and general health/disease status;

   4. import of a founder (F-0) population and quarantine in a secure facility;

   5. produce F-1 generation from the F-0 stock in quarantine;

   6. culture F-1 stock and at critical times in its development (life cycle) sample and test for infection with G. salaris and perform general examinations for pests and general health/disease status;

   7. if infection with G. salaris is not detected, pests are not present, and the general health/disease status of the stock is considered to meet the basic biosecurity conditions of the importing country, zone or compartment, the F-1 stock may be defined as infection with G. salaris free or specific pathogen free (SPF) for infection with G. salaris;

   8. release SPF F-1 stock from quarantine for aquaculture or stocking purposes in the country, zone or compartment.

4. With respect to point 3 e), quarantine conditions should be conducive to multiplication of the pathogen and eventually to clinical expression. If quarantine conditions are not suitable for pathogen multiplication and development, the recommended diagnostic approach might not be sensitive enough to detect low infection level.

This Article does not apply to aquatic animals referred to in point 1 of Article 10.3.3.

Article 10.3.9.

Importation of aquatic animals and aquatic animal products for processing for human consumption from a country, zone or compartment not declared free from infection with G. salaris

When importing, for processing for human consumption, aquatic animals or aquatic animal products of species referred to in Article 10.3.2. from a country, zone or compartment not declared free from infection with G. salaris, the Competent Authority of the importing country should assess the risk and, if justified, require that:

1. the consignment is delivered directly to and held in quarantine or containment facilities until processing into one of the products referred to in point 1 of Article 10.3.3., or products described in point 1 of Article 10.3.11., or other products authorised by the Competent Authority; and

2. water used in transport and all effluent and waste materials from the processing are treated in a manner that ensures inactivation of G. salaris or is disposed in a manner that prevents contact of waste with susceptible species.

For these commodities Member Countries may wish to consider introducing internal measures to address the risks associated with the commodity being used for any purpose other than for human consumption.

Article 10.3.10.

Importation of live aquatic animals intended for use in animal feed, or for agricultural, industrial or pharmaceutical use, from a country, zone or compartment not declared free from infection with G.salaris

When importing, for use in animal feed or for agricultural, industrial or pharmaceutical use, live aquatic animals of species referred to in Article 10.3.2. from a country, zone or compartment not declared free from infection with G. salaris, the Competent Authority of the importing country should:

1. require an international aquatic animal health certificate issued by the Competent Authority of the exporting country attesting that the aquatic animals have been held, immediately prior to export, in water with a salinity of at least 25 ppt for a continuous period of at least 14 days, and no other live aquatic animals of the species referred to in Article 10.3.2. have been introduced during that period;

OR

2. require that the consignment be delivered directly to and held in quarantine facilities for slaughter and processing into one of the products referred to in point 1 of Article 10.3.3. or other products authorised by the Competent Authority, and water used in transport and all effluent and waste materials be treated in a manner that ensures inactivation of G. salaris.

This Article does not apply to commodities referred to in point 1 of Article 10.3.3.

Article 10.3.11.

Importation of aquatic animals and aquatic animal products for retail trade for human consumption from a country, zone or compartment not declared free from infection with G. salaris

1. Competent Authorities should not require any conditions related to infection with G. salaris, regardless of the infection with G. salaris status of the exporting country, zone or compartment, when authorising the importation or transit of the following commodities which have been prepared and packaged for retail trade and which comply with Article 5.4.2.:

   • no commodities listed.

2. When importing aquatic animals or aquatic animal products, other than those referred to in point 1 above, of species referred to in Article 10.3.2. from a country, zone or compartment not declared free from infection with G. salaris, the Competent Authority of the importing country should assess the risk and apply appropriate risk mitigation measures.