. /.WORLD TRADE
ORGANIZATIONG/SPS/GEN/383
2 April 2003
(03-1846)
Committee on Sanitary and Phytosanitary Measures Original:  Spanish
CHILE:  FREE OF AVIAN INFLUENZA
Communication by Chile
1. In May 2002, the presence of the Avian Influenza (AI) virus was detected in a flock of
commercial poultry in Chile.  The disease had never previously been detected in Chile or  South
America.
2. The outbreak in question affected a flock of meat-producing breeding hens in the Province of
San Antonio, in Chile's Fifth Region.  The emergency response plan of the official veterinary service(Agriculture and Livestock Service - SAG) for OIE List A diseases was activated.
3. Quarantine measures were adopted at the point of outbreak and all of the 460,000 birds in the
flock were slaughtered.  There was a second outbreak in a flock of breeding turkeys owned by the
same company, located 4 kilometres away.  The flock was quarantined and both groups of affected
birds were slaughtered (18,000 birds).  The remainder of the flock was subjected to strict biosecuritymeasures and active epidemiological surveillance.  After the depopulation, a process of cleaning and
sanitizing was initiated and sentinel birds were introduced in both flocks.
4. The virus involved was identified as highly pathogenic H7N3, which apparently resulted from
the mutation of a low-pathogenic strain.
5. A perifocal zone 10 kilometres in radius was established around the two single points of
outbreak.  In this zone, there were 17 flocks of commercial poultry (meat and eggs) and 35 flocks of
backyard poultry.  Biosecurity and movement control measures were maximized, and activesurveillance took place at 7 to 15 day intervals, depending on the risk.
6. Biosecurity measures in the poultry industry were also stepped up in the rest of the country,
with passive and active surveillance of commercial flocks.  In August and subsequently in
November 2002, serological samples were taken at the national level from all flocks of commercial
poultry (578) and backyard poultry that were at risk.  Neither study revealed any cases ofseropositivity to AI.
7. An OIE Mission, comprising specialists from the Venice Reference Centre (Italy) was called
in by the SAG to inspect the eradication campaign and provide advice.  It approved of the strategy
adopted by Chile and all of the observations were accepted.
8. It has not yet been fully determined how A1 was introduced into Chile.  The investigation is
still under way.
9. The epidemiological surveillance process revealed that a group of meat-producing flocks,
owned by a company different to the one affected by the outbreaks, tested serologically positive for
AI type H5N2, without any clinical manifestation or viral isolation.  Epidemiological investigationsG/SPS/GEN/383
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and findings of the SAG laboratory, using RT-PCR and sero-conversion in chicks, linked this to the
use of an imported Inclusion Body Hepatitis vaccine that was contaminated with AI antigens.  These
results were confirmed by reference laboratories in the United States and the United Kingdom.
10. The process of disinfecting the outbreak points in the eradication zone and using susceptible
chicks and baby turkeys as sentinel birds provid ed evidence of the absence of infection in the
outbreak zone.  Similarly, the active surveillance in the perifocal zone and in the rest of the country
provided no evidence of the presence of the disease.
11. On 19 December 2002, in accordance with the OIE Animal Health Code, Chile declared the
entire country free of AI once again.  Thus, Chil e is once again free of all OIE List A diseases.
12. Since then, a post-eradication AI prevention strategy has been implemented, including, in
particular, measures such as import requirements for poultry and poultry products, import quarantine,
compulsory registration of poultry flocks, movement control, active and passive surveillance andbiosecurity in flocks.
13. Through its competent health authority (SAG), Ch ile offers foreign markets full guarantees on
its poultry products.  These have been accepted by all traditional poultry-importing countries with the
exception of a few which are currently considering the matter.
14. It is noteworthy that, from the beginning of th e AI outbreak, Chile kept the OIE and all of its
trading partners permanently and fully informed.  Furthermore, the SAG suspended all its exports of
poultry products as soon as it received confirmation of the highly pathogenic strain of AI.  Exports
recommenced only when Chile received a clean bill of health.
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