INFLUENZA A H1N1, CHILE
Information received on 31/08/2009 from Dr Ternicier Claudio, Jefe División Protección Pecuaria, Servicio Agrícola y Ganadero, Ministerio de Agricultura, Santiago, Chile.
Summary
| Report type | Follow-up report No. 1 |
| Start date | 23/07/2009 |
| Date of first confirmation of the event | 20/08/2009 |
| Report date | 31/08/2009 |
| Date submitted to OIE | 31/08/2009 |
| Date event resolved | 23/10/2009 |
| Reason for notification | Emerging disease |
| Morbidity | 61.4 % |
| Mortality | 0 % |
| Zoonotic impact | No |
| Causal agent | Influenza A virus |
| Related reports | |
| Outbreaks | There are no new outbreaks in this report |
Epidemiology
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Source of the outbreak(s) or origin of infection |
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| Epidemiological comments | To date, serological surveillance carried out in 100% of the remaining farms of the same company was negative. Data on mortality and production in these farms are normal. In the rest of the country, the results of the routine surveillance programme for avian influenza in poultry were negative. The samples taken from wild birds near the outbreaks were negative for influenza. In two breeding turkey flocks, the laying has returned to normal; there are still four flocks which should recover their normal laying rates. A biosecurity programme has been established in order to contain the infection in the infected flocks and to prevent it on the farms of the company that remain negative. Moreover, a plan to eradicate the virus in the affected farms has been established and it includes sending the birds to slaughter at the end of their production period and once the absence of viral excretion is established on serial samples taken through a rapid test and verifying it by RRT-PCR for the matrix. Tracing back of the movements of people towards and between farms is ongoing. During the week before laying began dropping the peak of human cases of influenza A H1N1 was recorded in the area where poultry farms are located (epidemiological week 28). Regarding the laboratory tests: – The affected premises have been systematically monitored through serological tests with negative results until 28 July this year. – On 16 August influenza A was detected by RRT-PCR for the matrix gene, according to the protocol described by Spackman (NVSL/USDA), on samples from tracheal and cloacae swabs, negative for H5 and H7 by RRT-PCR. Subtyping by serology (HI, NI) confirmed the detection of an influenza virus type A H1N1. – The RNA of this virus of the influenza A H1N1 was sent to the Public Health Institute of Chile (ISP), Ministry of Health, with a positive result for influenza A H1N1, by real-time RRT-PCR, according to CDC protocol. The RRT-PCR for seasonal influenza H1 and H3 was negative. – The ISP determined the complete genome sequence of the 8 genes (HA, NA, PA, PB, PB2, NP, NS and M) of the H1N1 influenza virus found in turkeys, comparing the similarity percentage with the A/California/4/2009 strain and the H1N1 influenza from Chile: for the HA gene, 99.5% and 100%; for NA, 99.5% and 99.7%; for PB1, 99.8% and 99.9%; for PB2, 99.8% and 99.8%; for PA, 99.7% and 99.9%; for NP, 99.5% and 99.7%; for NS, 99.8% and 99.8%; for M, 99.8% and 99.7%. The ISP concludes that the influenza virus A (H1N1) from turkeys corresponds to the same viral variant of the virus A (H1N1) 2009 which has been circulating this winter in our country (access number Gene Bank GQ 200279 to GQ 200286). – The National Veterinary Services Laboratory (NVSL), United States, indicates positive results through real time RT-PCR for novel N1 (SEPRL, Southeast Poultry Research Laboratory, Georgia, USA), for NI (NVSL/WI), for H1 (CDC) and a homology of the HA gene 99.6% similar to CA/14/2009, 99.7% similar to MX/4108/2009 and 100% similar to NY/18/2009. The neuraminidase gene shows a homology of 99.6% to MX/4108/2009, CA/4/2009, AZ/02/2009 and KS/02/2009. |
Control measures
| Measures applied |
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| Measures to be applied |
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Diagnostic test results
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Laboratory name and type |
Public Health Institute (National laboratory) |
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Tests and results |
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Laboratory name and type |
Quarantine Stations and Laboratories Department, SAG (National laboratory) |
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Tests and results |
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Laboratory name and type |
National Veterinary Services Laboratory (NVSL), United States (OIE’s Reference Laboratory) |
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Tests and results |
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Future Reporting
| The event is continuing. Weekly follow-up reports will be submitted. |
