WORLD TRADE
ORGANIZATIONG/SPS/N/MEX/189
5 August 2002
(02-4296)
Committee on Sanitary and Phytosanitary Measures Original:  Spanish
NOTIFICATION OF EMERGENCY MEASURES
1. Member to Agreement notifying:  MEXICO
If applicable, name of local government involved:
2. Agency responsible:  Ministry of Agriculture, Livestock, Rural Development, Fisheries
and Food
3. Products covered (provide tariff item number(s) as specified in national schedules
deposited with the WTO; ICS numbers may be provided in addition, where
applicable).  Penaeid shrimps
4. Regions or countries likely to be affected, to the extent relevant or practicable:  All
countries which are engaged in shrimp farming and trade in shrimps with Mexico.
5. Title and number of pages of the notified document:  Mexican Official Emergency
Standard NOM-EM-05-PESC-2002 Establishing the Requirements and Measures for the
Prevention and Control of  the Spread of High-Impact Diseases and for the Use and
Application of Antibiotics in Domestic Shrimp Farming  (9 pages).
6. Description of content:  The purpose of this Mexican Official Emergency Standard is to
establish the  requirements and measures for the prevention and control of  the spread of
high-impact diseases and for the use and application of antibiotics in domestic shrimpfarming.
This Standard is in partial conformity with Council Directive 96/23/EC, published
on 29 April 1996, on measures to monitor certain substances and residues thereof in live
animals and animal products and repealing Di rectives 85/358/EEC and 86/469/EEC and
Decisions 89/187/EEC and 91/664/EEC , and with the provisions of USC Regulation No. 21
of the Republic of Chile on measures to protect against, control and eradicate high-risk
diseases of hydrobiological species .
7. Objective and rationale:  [  X ] food safety,  [  X ] animal health,  [     ] plant protection,
[    ] protect humans from animal/plant pest or disease,
[    ] protect territory from other damage from pests
8. Nature of the urgent problem(s) and reasons for urgent action:   A range of diseases,
including viral diseases, have been identified at global level in farmed aquatic organisms
and present a high risk to aquaculture given that, since no effective control treatment is
currently available, mortality rates of up to one hundred per cent of affected populations
have been recorded.
Farmed shrimps in Asia and Central and South America have been adversely
affected by several viral diseases which have caused substantial economic losses to
production in countries such as China, Thailand and Ecuador.G/SPS/N/MEX/189
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8. Nature of the urgent problem(s) and reasons for urgent action:  (cont'd)
The Mexican Republic has proved no exception to this phenomenon: since the early
nineties, Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV), Taura
Syndrome Virus (TSV), White Spot Syndrome Virus (WSSV) and other viral diseases have
been identified in its domestic shrimp farming industry.
Diagnostic laboratories studying the diseases which affect penaeid shrimps farmed
in the national territory have, since 1999, been continually identifying and confirming the
presence of cases in which the affected specimens under review present the classicsymptoms of Taura Syndrome Virus (TSV), along with those caused by the White Spot
Syndrome Virus (WSSV) and Infectious Hypodermal and Haematopoietic Necrosis Virus
(IHHNV).
Farmed shrimps are also affected by other pathogens such as bacteria, for which,
unlike viral diseases, control treatment does exist.
There is evidence that the disease-carrying causal agents which affect farmed
shrimps come from asymptomatic carriers and are introduced to or spread from oneaquaculture production unit, district, State, region or coast to another across water by birds,
other animals, utensils, vehicles, etc.
In the event of an outbreak of disease in a shrimp aquaculture production unit, the
causal agent is spread by the water to other ponds in the same unit by way of the waste
water outfall entering the receiving body of water, a situation which increases the risk ofother production units supplied by this body of water introducing the disease-carrying
causal agent into their own installations, with the resulting threat of an outbreak or an
epizootic disease.
The quality of the water used for farming aquaculture species such as the penaeid
shrimp is a critical element in the production process and must therefore be monitored. Itsphysical, chemical and biological parameters, including, inter alia , the type of plankton
introduced into the aquaculture production unit, the suspended solids, total solids, nitrites,
nitrates, salinity, temperature, etc., must be suitable for the shrimps to grow and fatten
properly, otherwise the farmed population runs a great risk of outbreaks of disease and
mortalities as a result of deficiencies or changes in these parameters.
Faced with the problems described above, the aquaculture authorities in several
countries have adopted a number of requirements and measures to prevent and control the
spread of diseases affecting farmed shrimps, such as certification of the different stages of
development of penaeid shrimps used in production, and in relation to the chemical
substances used in disease control and prevention.
The results of the laboratory tests conducted in national territory on postlarvae
penaeid shrimps caught from natural populations have proved that, at this stage of
development, they are carriers of the causal agents of White Spot Syndrome Virus (WSSV)
and Taura Syndrome Virus (STV), amongst other viruses, which means that there is a high
risk of these diseases being introduced to aquaculture production units supplied by the same
source.
Farmed shrimps have a two-phase production process. The first phase corresponds
to the cultivation itself, which begins when shrimps in their early stages of development,
produced in laboratory-controlled conditions, are introduced into the installations of an
aquaculture production unit for fattening, and ends when commercial-size specimens areG/SPS/N/MEX/189
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8. Nature of the urgent problem(s) and reasons for urgent action:  (cont'd)
removed. The second phase begins when the harvested organisms are taken to market for
sale, either fresh or in ice, or sent to a plant for processing.
Therapeutic agents, such as antibiotics, are used to prevent and control diseases
which can be treated, such as bacterial diseases. Incorrect use can lead to an accumulation
of the residues of such products in the aquaculture species harvested.
A wide range of antibiotics exist for treating bacterial diseases in aquaculture, such
as chloramphenicol and nitrofurans. The latter belong to a group of synthetic antimicrobialcompounds, including furazolidone, which are considered a risk to human health, owing to
the metabolites generated during the metabolism of the drug in the live animal and
subsequent to its slaughter.
To date, the competent authorities with re gard to health and aquatic regulations in
other countries have not authorised the use of such substances in aquaculture. However, insome nations, such as the United States of America, some may be used upon request and
subject to an assessment of the case in question, provided that their application and use are
supervised by a specialist accredited by the competent authority.
The European Union has recently detected chloramphenicol residues in shipments
of farmed shrimps from Asia, which has led to the suspension of imports of this crustacean
to Europe. Moreover, European countries, in conjunction with other nations such as the
United States of America, are carrying out stricter monitoring, with a view to detectingresidues of chloramphenicol and other antibiotics, such as those belonging to the nitrofuran
group (including furazolidone), in shrimps imported from other countries.
In the light of the above and considering that water is a critical factor in the penaeid
shrimp production process and that another critical factor in shrimp farming is the use of
therapeutic agents, of which antibiotics are the most frequently used, there is a need fortechnical regulations to be established to prevent the spread of high-impact diseases in
shrimp farming, such as White Spot Syndrome Virus (WSSV), Infectious Hypodermal and
Haematopoietic Necrosis Virus (IHHNV), Taura Syndrome Virus (TSV) and any others
which are notified to the Ministry of Agricult ure, Livestock, Rural Development, Fisheries
and Food by way of a notice published in the Diario Oficial de la Federación  (Official
Journal).
9. International standard, guideline or recommendation:
[    ] Codex Alimentarius Commission,  [    ] Office International des Epizooties,
[    ] International Plant Protection Convention, [ X ] None
If an international standard, guideline or recommendation exists, give the appropriate
reference and briefly identify deviations:  None, although this Standard is in partial
conformity with Council Directive 96/23/EC of 29 April 1996 on measures to monitor
certain substances and residues thereof in live animals and animal products and repealing
Directives 85/358/EEC and 86/469/EEC and Decisions 89/187/EEC and 91/664/EEC, as
well as being similar in part to the provisions of USC Regulation No. 21 of the Republic of
Chile on measures to protect against, control and eradicate high-risk diseases for
hydrobiological species .
10. Relevant documents and language(s) in which these are available:  Diario Oficial de la
Federación  (Official Journal) of 19 July 2002  (available in Spanish).G/SPS/N/MEX/189
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11. Date of entry into force/period of application (as applicable):  20 July 2002.
12. Agency or authority designated to handle comments: [ X ] National notification
authority, [    ] National enquiry point, or address, fax number and E-mail address (if
available) of other body:
13. Texts available from:  [  X ] National notification authority, [    ] National enquiry point
or address, fax number and E-mail address (if available) of other body:
Ms Jessica Gutierrez
E-mail:  cidgn@economia.gob.mx
Web site:   www.economia.gob.mx/?P=85 (Standards catalogue)Directorate-General of Standards
Tel.: (52+55) 57 29 93 00, Ext. 4156Fax: 55 20 97 15