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Ilaria Capua

Publications and source records attributed to Ilaria Capua.

At least 19 recordsLinked to original sources
PubMed2006

Control and prevention of avian influenza in an evolving scenario.

Continuing outbreaks of highly pathogenic avian influenza (HPAI) across Eurasia and in Africa, caused by a type A influenza virus of the H5N1 subtype appear out of control and represent a serious risk for animal and public health worldwide. It is known that biosecurity represents the first line of defence against AI, although in certain circumstances strict hygienic measures appear to be inapplicable for social and economic conditions. The option of using vaccination against AI viruses of the H5 and H7 subtypes, has made its way in recent times--primarily as a tool to maximise the outcome of a series of control measures in countries that are currently infected, but also as a means of reducing the risk of introduction in areas at high risk of infection. In developing countries vaccination programmes in avian species have been recommended recently, however it will require concurrent management of local husbandry practices and industry compliance to eradicate the disease rather than the establishment of an endemic situation. Other key deliverables expected for this control strategy include maintaining a major source of food for rural communities and the preservation of the commercial viability of the local poultry industry. In developed countries vaccination is being used as a means of increasing resistance of susceptible animals to reduce the risk of introduction from the reservoir host or to reduce secondary spread in densely populated poultry areas. The recent joint OIE/FAO summits recommended applying vaccination, using the differentiating infected from vaccinated animals (DIVA) strategy when there is risk of major spread and depopulation is not feasible or desirable. Particularly in developing countries, stamping out of infected animals does not seem to be an appropriate means of reducing the spread of infection, if food supplies are to be guaranteed and economic consequences minimised. Crucial points to the success of a vaccination campaign are the implementation of complex territorial strategy involving upgraded biosecurity, monitoring vaccine efficacy, identification of field exposure and the appropriate management of infected flocks, regardless of vaccination status. Granting financial support for the compensation of farmers is also a key part of this strategy. Poultry veterinarians working for the industry or for the public sector represent the first line of defence against the pandemic threat and for the prevention and control of this infection in poultry and in wild birds.

Animals↗
PubMed2006

Progressive truncation of the Non-Structural 1 gene of H7N1 avian influenza viruses following extensive circulation in poultry.

In order to support eradication efforts of avian influenza (AI) infections in poultry, the implementation of "DIVA" vaccination strategies, enabling the Differentiation of Infected from Vaccinated Animals have been recommended by international organisations. A system, based on the detection of antibodies to the Non-Structural 1 (NS1) protein of AI has been proposed but the success of such a system lies in the conservation of the NS1 protein among different AI isolates. With this in mind, the ns1 gene of 40 influenza A viruses isolated from a spectrum of avian species was sequenced and compared phylogenetically. The isolates included both low pathogenicity (LPAI) (n=22) and highly pathogenic (HPAI) (n=18) viruses of the H7 subtype and were representative of the avian influenza viruses that circulated in Northern Italy from 1999 to 2003. Size variation in the predicted amino acid sequence of each NS1 was revealed with two different levels of carboxy-terminal truncation being observed. Of the 40 isolates analysed, 16 had a full-length NS1 protein of 230 aa, 6 had a truncated protein of 220 aa and 18 had an intermediate truncation resulting in a protein of 224 aa. All of the H7N1 HPAI isolates possessed the intermediate carboxy-terminal truncation. In addition, all of the H7N1 LPAI viruses circulating at the beginning of the epidemic had a full length NS1 while those circulating towards the end of the period had a truncated protein. To determine whether modifications to NS1 could be a result of laboratory manipulation, two strains (A/ty/Italy/977/99 and A/ck/Italy/1082/99) with a full length NS1 were inoculated into 10-day-old embryonated chicken and 12-day-old embryonated turkey eggs via the allantoic route for 20 blind passages and sequenced at passages 3, 10, and 20. No truncation was observed following these serial passages. To determine whether the truncation involved an immunogenic region of the NS1 protein a peptide spanning residues 219 aa to 230 aa was synthesized and tested in an indirect ELISA against sera obtained from turkeys experimentally infected with a virus strain known to have a full length NS1 protein. The peptide proved to be immunogenic highlighting the fact that the variations of the NS1 protein presented in this work must to be taken into consideration when developing a diagnostic test based on the identification of antibodies to the NS1 protein.

Amino Acid Sequence↗
PubMed2006

Development and validation of an anti-N3 indirect immunofluorescent antibody test to be used as a companion diagnostic test in the framework of a "DIVA" vaccination strategy for avian influenza infections in poultry.

Avian influenza (AI) infections have become of growing importance both for animal and human health. Vaccination has become a recommended tool to support eradication efforts and limit the economic losses caused by this disease. The "DIVA" system, using a vaccine containing a heterologous neuraminidase to the field virus, has been shown to be an effective tool in increasing the resistance of birds to field challenge, preventing clinical signs and reducing viral shedding in the environment. The companion diagnostic test to the vaccine, however, has been only partially validated in the field against one subtype of neuraminidase (N1). The present paper presents the results of a full laboratory and field validation of the diagnostic test developed to detect antibodies to the N3 subtype of AI in vaccinated and unvaccinated chickens and turkeys. Antibody kinetic studies conducted in the laboratory have shown that antibodies to the N protein may be detected earlier than antibodies to the haemagglutinin. The data derived from this extensive validation trial indicate the excellent capability of this assay in detecting the presence of active AI infection at an early stage in both unvaccinated and vaccinated birds and the lack of interference with vaccine-induced antibodies.

Animals↗
PubMed2006

The challenge of avian influenza to the veterinary community.

Avian influenza (AI) is a listed disease of the World Organisation for Animal Health (OIE) that has become a disease of great importance both for animal and human health. The increased relevance of AI in the fields of animal and human health has highlighted the lack of scientific information on several aspects of the disease, which has hampered the adequate management of some of the recent crises. Millions of animals have died, and there is growing concern over the loss of human lives and over the management of the pandemic potential. The present paper aims to identify areas of knowledge of veterinary competence that need to be improved in order to generate information to support the global AI crisis, and highlights the major changes in AI legislation, including regulations related to trade. It also reviews the human health implications of AI, including the mechanisms by which a human pandemic virus may be generated, and the food safety issues related to this infection. The application of control policies, ranging from stamping out to emergency and prophylactic vaccination, are discussed on the basis of data generated in recent outbreaks, and in the light of new regulations, also in view of the maintenance of good animal welfare. Poultry veterinarians working for the industry or for the public sector represent the first line of defence against the pandemic threat and for the prevention and control of this infection in poultry and in wild birds. However, given the current situation, it is imperative that close collaboration is sought and achieved by health officials involved in the veterinary, agricultural and medical aspects of the disease. Only through the exchange of data, experiences, views and information will it be possible to combat this zoonosis, which represents a major threat to public health and animal well-being.

Animals↗
PubMed2006

Isolation and characterization of an H10N7 avian influenza virus from poultry carcasses smuggled from China into Italy.

Intensified official veterinary controls on warehouses supplying Chinese retailers resulted in the seizure of smuggled poultry products. Frozen and vacuum-packed frozen raw duck and chicken carcasses, and anatomic parts (legs) of these species, were collected and processed for laboratory investigations aiming at the detection of avian influenza virus. Real-time reverse transcription-polymerase chain reaction (RRT-PCR) targeting the M gene, performed on the lung and trachea from duck and chicken carcasses, yielded positive results. Virus isolation attempts in specific pathogen free embryonated eggs yielded an H10N7 virus from the duck carcass. The isolate had an intravenous pathogenicity index of 0.0, and phylogenetic analysis revealed a nucleotide homology of 97 and 96% with virus A/duck/Zhejiang/52/2000 (H5N1) for the PB2 and NS genes, respectively. The results of this study indicate that low-pathogenicity avian influenza viruses may be introduced into a country through trade of carcasses regardless of the non-systemic nature of this disease. The export ban applied to countries affected by the H5N1 epidemic may result in increased smuggling of poultry products, which remains one of the means by which influenza viruses can cross-national boundaries. Increased surveillance at borders and at a national level is recommended.

Animals↗
PubMed2006

Control of avian influenza infections in poultry with emphasis on vaccination.

Avian influenza is a World Organization for Animal Heath-listed disease that has become of great importance both for animal and human health. The increased relevance of avian influenza in the fields of animal and human health has highlighted the lack of scientific information on several aspects of the disease, which has hampered the adequate management of some of the recent crises. Millions of animals have died and there is growing concern over the loss of human lives and over the management of the pandemic potential. This special report will review the control methods for avian influenza infections in poultry that are currently available. The application of control policies, ranging from stamping out to emergency and prophylactic vaccination, are discussed on the basis of data generated from recent outbreaks, in the light of new regulations and also in view of the maintenance of animal welfare. Poultry veterinarians working for the industry or for the public sector represent the first line of defense against the pandemic threat and for the prevention and control of this infection in poultry and in wild birds.

Animals↗
PubMed2006

Control of avian influenza in poultry.

Avian influenza, listed by the World Organization for Animal Health (OIE), has become a disease of great importance for animal and human health. Several aspects of the disease lack scientific information, which has hampered the management of some recent crises. Millions of animals have died, and concern is growing over the loss of human lives and management of the pandemic potential. On the basis of data generated in recent outbreaks and in light of new OIE regulations and maintenance of animal welfare, we review the available control methods for avian influenza infections in poultry, from stamping out to prevention through emergency and prophylactic vaccination.

Animals↗
PubMed2005

Serological analysis of serum samples from humans exposed to avian H7 influenza viruses in Italy between 1999 and 2003.

We evaluated the potential for avian-to-human transmission of low pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI) H7N1 and LPAI H7N3 viruses that were responsible for several outbreaks of influenza in poultry in Italy between 1999 and 2003. A serological survey of poultry workers was conducted by use of a combination of methods. Evidence of anti-H7 antibodies was observed in 3.8% of serum samples collected from poultry workers during the period in 2003 when LPAI H7N3 virus was circulating. These findings highlight the need for surveillance in people occupationally exposed to avian influenza viruses, so that they can be monitored for the risk of avian-to-human transmission during outbreaks of avian influenza caused by both LPAI and HPAI viruses.

Agricultural Workers' Diseases↗
PubMed2004

Increased resistance of vaccinated turkeys to experimental infection with an H7N3 low-pathogenicity avian influenza virus.

A trial was performed to establish whether turkeys vaccinated against avian influenza with a vaccine containing a strain with a heterologous neuraminidase to the challenge virus required a higher infectious dose to develop infection than naïve birds. Birds were vaccinated with a commercially available, inactivated oil emulsion product containing the strain A/ty/Italy/99/(H7N1) and challenged with different dilutions of a LPAI isolate A/ty/Italy/8000/02(H7N3) obtained during the 2002 to 2003 Italian epidemic. Groups of 10 vaccinated and 10 unvaccinated birds were infected experimentally with a virus suspension containing 10(2), 10(4) and 10(6) median embryo infective dose (EID50)/0.1 ml. Infected birds were observed daily with tracheal and cloacal swabs collected at regular intervals for antigen detection, virus isolation and real-time reverse transcription-polymerase chain reaction. Pre-infection and post-infection serology was also performed. The results of the experiment indicate that infection is achieved in naïve birds with 10(4) EID50, while vaccinated birds are resistant at this challenge dose. Vaccinated and unvaccinated birds were susceptible to infection with 10(6) EID50, although the duration and/or the number of birds shedding was reduced in the vaccinated group. The data presented indicate that heterologous vaccination in the framework of a 'Differentiating Infected from Vaccinated Animals' strategy can be a valid tool to support eradication measures in areas with high densities of susceptible animals. .

Animals↗
PubMed2004

Avian influenza: recent developments.

This paper reviews the worldwide situation regarding avian influenza infections in poultry from 1997 to March 2004. The increase in the number of primary introductions and the scientific data available on the molecular basis of pathogenicity have generated concerns particularly for legislative purposes and for international trade. This has led to a new proposed definition of 'avian influenza' to extend all infections caused by H5 and H7 viruses regardless of their virulence as notifiable diseases, although this has encountered some difficulties in being approved. The paper also reviews the major outbreaks caused by viruses of the H5 or H7 subtype and the control measures applied. The zoonotic aspects of avian influenza, which until 1997 were considered to be of limited relevance in human medicine, are also discussed. The human health implications have now gained importance, both for illness and fatalities that have occurred following natural infection with avian viruses, and for the potential of generating a reassortant virus that could give rise to the next human influenza pandemic.

Animals↗
PubMed2003

Matrix protein gene sequence analysis of avian paramyxovirus 1 isolates obtained from pigeons.

The matrix protein gene was cloned and sequenced for several recent isolates of avian paramyxovirus type 1 (APMV-1). Specifically, isolates from pigeons and doves, members of the Columbidae family were examined. APMV-1 is the causative agent of Newcastle disease and the virus is associated with disease among a diverse number of avian species. Newcastle disease virus (NDV) isolates from pigeons have also been classified as pigeon paramyxovirus type 1 (PPMV-1). Matrix protein gene sequences for PPMV-1 isolates clustered together as a group relative to isolates from other species phylogenetically. However, there were also isolates from pigeons or doves that grouped with APMV-1 isolates from other species. This indicates that PPMV-1 may be circulating among Columbidae members as a distinct lineage, but that these avian species may also harbor other NDV strains as well. Of particular interest was a dove isolate from Europe that had an aberrant fusion protein cleavage site and was an outlying member phylogenetically between the two major groups of APMV-1 isolates.

Amino Acid Sequence↗
PubMed2003

Development of a DIVA (Differentiating Infected from Vaccinated Animals) strategy using a vaccine containing a heterologous neuraminidase for the control of avian influenza.

The present paper reports of the development and validation of a control strategy for avian influenza infections in poultry. The "DIVA" (Differentiating Infected from Vaccinated Animals) strategy is based on the use of an inactivated oil emulsion vaccine containing the same haemagglutinin (H) subtype as the challenge virus, but a different neuraminidase (N). The possibility of using the heterologous N subtype, to differentiate between vaccinated and naturally infected birds, was investigated through the development of an "ad hoc" serological test based on the detection of specific anti-N1 antibodies. This was achieved using a baculovirus expressing a recombinant N1 protein. The A/ck/Pakistan/H7N3 virus was used as a vaccine and birds were challenged with the HPAI A/ty/Italy/4580/V99/H7N1 strain. The homologous H group ensured a clinical protection of 93% regardless of the vaccination scheme used, and was able to prevent viraemia and muscle colonization in the clinically healthy challenged birds. However, it was not able to prevent viral shedding. The "ad hoc" serological assay was developed as an indirect immunofluorescence test, and was validated using 608 field sera, and showed an "almost perfect agreement" (Kappa value) with the HI test, with relative sensitivity and specificity values of 98.1 and 95.7, respectively. The results of the present investigation suggest that the "DIVA" control strategy may represent a tool for the control of avian influenza infections in poultry.

Animals↗