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The Italian experience in the control of Avian Influenza applying emergency and prophylactic vaccination. Luca Busani Istituto Zooprofilattico Sperimentale delle Venezie. The AI challenge in Italy.
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The Italian experience in the control of Avian Influenza applying emergency and prophylactic vaccination Luca Busani Istituto Zooprofilattico Sperimentale delle Venezie
The AI challenge in Italy • High density of susceptible species (turkeys) in a limited area (Densely Populated Poultry Area-DPPA) • Wetlands and resting sites for migratory waterfowl in close proximity of this DPPA • Several introductions of LPAI viruses from wild birds resulting in some cases in major epidemics
ITALY - VENETO AND LOMBARDY Distribution of poultry holdings Mallard population in Italy: 110,000 birds/year @ 3.300 poultry holdings @ 95 million bird places
Italy: AI outbreaks from 1997 to 2005 • 1997-1998 HPAI: H5N2 8 outbreaks, backyard flocks, prompt eradication • 2000 LPAI-HPAI: H7N1, total costs € 500 million • 2000-2001 LPAI: H7N1 78 outbreaks • 2002-2003 LPAI: H7N3 388 outbreaks • 2004 LPAI: H7N3 28 outbreaks (September-November) • 2005 LPAI: H5N2 15 outbreaks (April-May) Total direct costs: 170 million euros
LPAI: prevention control strategies • Increase of farms bio-security level • Prompt detection of any AI virus introduction in: • Poultry • Wild birds • Vaccination (H5–H7 virus subtypes) • Reduction of farm density, mainly turkey farms (long term strategy)
More than 1000 farms More than 31 million birds Veneto Lombardia VACCINATION AREA
Vaccination: data management system Reports to decision makers Laboratory data Poultry populations data Central data collection and analysis Monitoring activity Poultry vaccination data
Numbers of vaccination in Italy (2000-2006) Vaccination-related costs: 35 million € payed by the farmers
Weekly incidence rate of LPAI H7N3 outbreaks From 31/12/02 vaccination of turkeys (H7N1) R0=3.0 IC (2.3- 3.9) R0=0.6 IC (0.5-0.7)
LPAI epidemics and vaccination in Italy • emergency vaccination • preventative vaccination • c,d) poor adherence to the vaccination protocol • c) 17 flocks vaccinated only once or twice, instead of three times as scheduled; • d) all flocks vaccinated only once
Conclusions I • Emergency and prophylactic AI vaccination can reduce financial losses due to AI epidemics • In order to maintain trade, vaccination must be coupled with monitoring and aimed at eradication • Wild birds and backyard flocks must be included in the monitoring programs • The problems related to AI vaccines and vaccination must be considered when intervention is planned
Conclusion II • Control of AI in DPPAs requires a coordinated territorial strategy including surveillance, early detection and prompt intervention and vaccination should be part of it • This strategy must be adapted to the field conditions • It requires dedicated resources • The sustainability in the long period is the major drawback
Grazie per l’attenzione… Luca Busani Istituto Zooprofilattico delle Venezie – CREVcrev.lbusani@izsvenezie.itStefano Marangon Istituto Zooprofilattico delle Veneziesmarangon@izsvenezie.it