Embed Size (px)
Citation preview
Luca Busani
Istituto Zooprofilattico Sperimentale delle Venezie
The Italian experience in the control of
Avian Influenza applying emergency and
prophylactic vaccination
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 LOMBARDYDistribution of poultry holdings
@ 3.300 poultry holdings
@ 95 million bird places
Mallard population in Italy:110,000 birds/year
Total direct costs: 170 million euros
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)
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)
VACCINATION AREA
Lombardia Veneto
More than 1000 farmsMore than 31 million birds
Laboratory data
Poultry populations data
Reports to decision makers
Central data collection and analysis
Poultry vaccination data
Monitoring activity
Vaccination: data management system
Numbers of vaccination in Italy (2000-2006)
2000-2002
2003 2004 2005 2006
Capons 41,000 301,000 268,000 192,000 211,000
Guinea Fowls - - 84,000 75,000 41,000
Cockerels - 1,061,000 1,261,000 - -
Laying hens 6,534,000 26,830,000 13,263,000 7,577,000 5,459,000
Turkeys 16,303,000 47,242,000 36,171,000 28,318,000 10,908,000
Total (doses) 23 million 75 million 51 million 36 million 17 million
Cost (€) 4 million 13 million 9 million 6 million 3 million
Vaccination-related costs: 35 million €payed by the farmers
From 31/12/02 vaccination of turkeys (H7N1)
R0=3.0IC (2.3- 3.9)
R0=0.6IC (0.5-0.7)
Weekly incidence rate of LPAI H7N3 outbreaks
a) emergency vaccination b) 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
LPAI epidemics and vaccination in Italy
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 – CREV
Stefano Marangon Istituto Zooprofilattico delle Venezie
