Istituto Zooprofilattico Sperimentale delle Venezie 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

Mallard population in Italy: 110,000 birds/year 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)

VACCINATION AREA More than 1000 farms More than 31 million birds Lombardia Veneto This is the area where the vaccination is in place since 2000, the blue line limits the vaccination area until 2004 that now is an intensive surveillance area, while the red line defines the actual vaccination area VACCINATION AREA

Vaccination: data management system Reports to decision makers Laboratory data Poultry populations data Central data collection and analysis If vaccination is to be used to complement rather than replace a stamping out policy this raises other issues. Possibly the most important of these will be how to identify a vaccinated flock infected with HPAI. This could be done by routine surveillance of vaccinated flocks, either by virus isolation or by using a marker vaccine [none are available at present] or one with a different neuraminidase to the field virus so that cheaper serological monitoring can be done or by using unvaccinated sentinel birds. Limited vaccination of part of the poultry industry considered most at risk has also been suggested. For example, breeder birds that live longer or replacement stock. However, if a stamping out policy is to be retained such birds would still be slaughtered if they became infected with HPAI virus. Vaccination in these circumstances would therefore be accepting that biosecurity measures and for replacements cleaning and disinfection were unlikely to be succesfull. Monitoring activity Poultry vaccination data

Numbers of vaccination in Italy (2000-2006) 2002 2003 2004 2005 2006 Capons 41,000 301,000 268,000 192,000 211,000 Guinea Fowls - 84,000 75,000 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 The other preventive measure in place is the vaccination, and the annual doses of vaccine administered in the last years ranged from 51 million to 36 million, this difference is due to the fact that in 2005 the vaccination area was reduced then a lower number of flocks were vaccinated conparing to 2004. 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

This strategy must be adapted to the field conditions 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 The Italian situation should be compared to other DPPAs troughout the world, and in thses areas, the control of AI requires a coordinated territorial strategy including surveillance, early detection and prompt intervention. In particular, the italian experience showed that vaccination is effective if applied with the aim to eradicate the infection, but such measures require dedicated resources, and, of course dedicated funds because their effective application is expensive and the costs involve the not only producers but also the society as a whole.

Grazie per l’attenzione… Luca Busani Istituto Zooprofilattico delle Venezie – CREV crev.lbusani@izsvenezie.it Stefano Marangon Istituto Zooprofilattico delle Venezie smarangon@izsvenezie.it