White tail disease

Article 9.8.1.

For the purposes of the Aquatic Code, white tail disease (WTD) means infection with macrobrachium nodavirus (MrNV). This virus has yet to be formally classified.

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

Article 9.8.2.

Scope

The recommendations in this chapter apply to: the giant fresh water prawn (Macrobrachium rosenbergii). Other common names are listed in the Aquatic Manual. These recommendations also apply to any other susceptible species referred to in the Aquatic Manual when traded internationally.

For the purposes of this chapter, the terms shrimp and prawn are used interchangeably.

Article 9.8.3.

Importation or transit of aquatic animals and aquatic animal products for any purpose from a country, zone or compartment not declared free from white tail disease

1. Competent Authorities should not require any conditions related to WTD, regardless of the WTD status of the exporting country, zone or compartment, when authorising the importation or transit of the following aquatic animal products from the species referred to in Article 9.8.2. which are intended for any purpose and which comply with Article 5.4.1.:

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

   2. cooked crustacean products that have been subjected to heat treatment at 60°C for at least 60 minutes (or any time/temperature equivalent which has been demonstrated to inactivate MrNV);

   3. pasteurised crustacean products that have been subjected to heat treatment at 90°C for at least ten minutes (or any time/temperature equivalent that has been shown to inactivate MrNV);

   4. crustacean oil;

   5. crustacean meal;

   6. chemically extracted chitin.

2. When authorising the importation or transit of aquatic animals and aquatic animal products of a species referred to in Article 9.8.2., other than those referred to in point 1 of Article 9.8.3., Competent Authorities should require the conditions prescribed in Articles 9.8.7. to 9.8.11. relevant to the WTD 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 9.8.2. but which could reasonably be expected to pose a risk of spread of WTD, the Competent Authority should conduct a risk analysis in accordance with the recommendations in Chapter 2.1. The Competent Authority of the exporting country should be informed of the outcome of this assessment.

Article 9.8.4.

Country free from white tail disease

If a country shares a zone with one or more other countries, it can only make a self-declaration of freedom from WTD if all the areas covered by the shared water bodies are declared countries or zones free from WTD (see Article 9.8.5.).

As described in Article 1.4.6., a country may make a self-declaration of freedom from WTD if:

1. none of the susceptible species referred to in Article 9.8.2. 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 9.8.2. 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 two 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 two years; and

   2. targeted surveillance, as described in Chapter 1.4., has been in place for at least the last two years without detection of WTD;

OR

4. it previously made a self-declaration of freedom from WTD and subsequently lost its disease free status due to the detection of WTD 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; 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 two years without detection of WTD.

   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 9.8.5.

Article 9.8.5.

Zone or compartment free from white tail disease

If a zone or compartment extends over more than one country, it can only be declared a WTD free zone or compartment 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 WTD 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 9.8.2. 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 9.8.2. are present in the zone or compartment and the following conditions have been met:

   1. there has not been any 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 two 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 two 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 two years without detection of WTD;

OR

4. it previously made a self-declaration of freedom for a zone from WTD and subsequently lost its disease free status due to the detection of WTD 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; 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 two years without detection of WTD.

Article 9.8.6.

Maintenance of free status

A country, zone or compartment that is declared free from WTD following the provisions of points 1 or 2 of Articles 9.8.4. or 9.8.5. (as relevant) may maintain its status as free from WTD provided that basic biosecurity conditions are continuously maintained.

A country, zone or compartment that is declared free from WTD following the provisions of point 3 of Articles 9.8.4. or 9.8.5. (as relevant) may discontinue targeted surveillance and maintain its status as free from WTD provided that conditions that are conducive to clinical expression of WTD, 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 WTD, 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 9.8.7.

Importation of aquatic animals and aquatic animal products from a country, zone or compartment declared free from white tail disease

When importing aquatic animals and aquatic animal products of species referred to in Article 9.8.2. from a country, zone or compartment declared free from WTD, 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 9.8.4. or 9.8.5. (as applicable) and 9.8.6., the place of production of the aquatic animals and aquatic animal products is a country, zone or compartment declared free from WTD.

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

This Article does not apply to commodities listed in point 1 of Article 9.8.3.

Article 9.8.8.

Importation of live aquatic animals for aquaculture from a country, zone or compartment not declared free from white tail disease

1. When importing, for aquaculture, live aquatic animals of species referred to in Article 9.8.2. from a country, zone or compartment not declared free from WTD, the Competent Authority of the importing country should assess the risk and, if justified, apply the following risk mitigation measures:

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

   2. the treatment of water used in transport and of all effluent and waste materials in a manner that ensures inactivation of WTDV.

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 considered.

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 health and disease history;

   3. take and test samples for WTDV, 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 WTD and perform general examinations for pests and general health/disease status;

   7. if WTDV 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 WTD free or specific pathogen free (SPF) for WTDV;

   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 listed in point 1 of Article 9.8.3.

Article 9.8.9.

Importation of aquatic animals and aquatic animal products for processing for human consumption from a country, zone or compartment not declared free from white tail disease

When importing, for processing for human consumption, aquatic animals or aquatic animal products of species referred to in Article 9.8.2. from a country, zone or compartment not declared free from WTD, 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 9.8.3., or products described in point 1 of Article 9.8.11., 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 WTDV 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 9.8.10.

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 white tail disease

When importing, for use in animal feed or for agricultural, industrial or pharmaceutical use, live aquatic animals of species referred to in Article 9.8.2. from a country, zone or compartment not declared free from WTD, the Competent Authority of the importing country should require that:

1. the consignment is delivered directly to, and held in, quarantine facilities for slaughter and processing into 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 WTDV.

This Article does not apply to commodities referred to in point 1 of Article 9.8.3.

Article 9.8.11.

Importation of aquatic animals and aquatic animal products for retail trade for human consumption from a country, zone or compartment not declared free from white tail disease

1. Competent Authorities should not require any conditions related to WTD, regardless of the WTD status of the exporting country, zone or compartment, when authorising the importation or transit of frozen peeled shrimp (shell off, head off) which have been prepared and packaged for retail trade and which comply with Article 5.4.2.

   Certain assumptions have been made in assessing the safety of the aquatic animal products mentioned above. Member Countries should refer to these assumptions at Article 5.4.2. and consider whether the assumptions apply to their conditions.

   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.

2. When importing aquatic animals or aquatic animal products, other than those referred to in point 1 above, of species referred to in Article 9.8.2. from a country, zone or compartment not declared free from WTD, the Competent Authority of the importing country should assess the risk and apply appropriate risk mitigation measures.