Surveillance strategies for foot and mouth disease to prove absence of disease and absence of viral circulation.

Free trade of animals and their products is based on the international or bilateral recognition of the health status of the animal populations being traded. This recognition is based on documentation of their health status by the exporting country, based on the results of continuing surveillance. According to the Terrestrial Animal Health Code of the World Organisation for Animal Health (OIE), this may be based on various methods of surveillance, such as: documenting non-specific surveillance (clinical surveillance, passive notification of suspect cases, etc.); documenting activities that increase the sensitivity of non-specific surveillance (training activities, rewards/sanctions for notification/failure to notify, etc.); documenting all specific surveillance and its results (random surveys, targeted and risk-based surveillance, convenience-testing activities, etc.). Usually, the infection is the subject of the declaration of freedom. While clinical and passive surveillance can provide a high level of confidence that foot and mouth disease (FMD) infection is absent, this is not the case in vaccinated populations. In these populations, specific surveillance becomes much more important than non-specific clinical surveillance. Specific surveillance is severely restricted by the performance of the test(s) employed. The imperfect specificity of any serological test is further complicated when techniques to differentiate infected from vaccinated animals (DIVA) are used, because imperfect purification of the antigen used for vaccination may foster the production of undesired antibodies in the vaccinated animals. The authors discuss various approaches to overcome this problem; their merits and flaws in documenting the absence of infection or virus circulation for animal diseases in general, and for FMD in particular. Particular attention is paid to finding methods that can be applied in a variety of epidemiological conditions and organisational structures, since these vary greatly among OIE Members.

Bluetongue control strategy, including recourse to vaccine: a critical review.

The bluetongue (BT) epidemic that has prevailed in Europe since 2000 is the first example of continental spread of the BT virus (BTV) in large naive populations of susceptible animals. Based on the results of intensive surveillance and research in countries of the southern Mediterranean that were affected by the infection early on in the epidemic, a new strategy for prevention and control of the disease was developed to limit direct losses and to reduce the consequences due to movement restrictions. The basic innovations that were introduced were the use of mass vaccination of all domestic ruminant species to limit the spread of BTV and the use of intensive active surveillance to limit, as far as possible, the zone where movement restrictions must be applied. The novel strategy that was adopted dramatically reduced the number of clinical outbreaks in southern Europe and the Mediterranean Basin and ensured safer animal trade. In 2006, the first BTV-8 epidemic occurred, this time in north-western Europe. During this epidemic, affected countries adopted a 'wait and see' approach. No vaccination was implemented until 2008 and, in many instances, the movement of animals was authorised within restricted areas, thereby facilitating the spread of infection. The delay in administering vaccination was due to the decision to avoid the use of modified live virus vaccines, although this type of vaccine performed satisfactorily in the previous BT epidemics in southern Europe. Bluetongue has demonstrated that the infectious agents present in southern Africa can easily spread to the Mediterranean Basin, which should be considered a single entity as far as the epidemiology of animal diseases is concerned. Therefore, any effective strategy for the prevention and control of animal disease in Europe must take into account this reality and recognise the need for regional surveillance networks that include all the countries that border the Mediterranean.

[Earthquake in Abruzzo, public health interventions. Preliminary report]. / Interventi sanitari in occasione del sisma in Abruzzo. Rapporto preliminare.

On 6th April 2009, at 3.32 AM, there was in L'Aquila and in some neighbouring villages, after an earthquake swarm last some months, an earthquake of M(L) = 5.8 (Richter magnitude scale) on depth of 8.8 km. The event was sensed in a very broad area, till in Rome and Ancon. The operative committee of the Civil Protection Department immediately gathered and a first operating group was despatched in the epicentre; the voluntary association of civil protection were in a pre-alarm situation and then were activated. This work want describe all the activities from 6th April 2009 till 31th August 2009, giving too a synthesis of the normative lines in case of catastrophic events typology C, otherwise all that events impossible to manage without national intervention.

Assessment of efficacy of a bivalent BTV-2 and BTV-4 inactivated vaccine by vaccination and challenge in cattle.

The efficacy of a bivalent inactivated vaccine against bluetongue virus (BTV) serotypes 2 (BTV-2) and 4 (BTV-4) was evaluated in cattle by general and local examination, serological follow-up, and challenge. Thirty-two 4-month-old calves were randomly allocated into 2 groups of 16 animals each. One group was vaccinated subcutaneously (s/c) with two injections of bivalent inactivated vaccine at a 28-day interval, and the second group was left unvaccinated and used as control. Sixty-five days after first vaccination, 8 vaccinated and 8 unvaccinated calves were s/c challenged with 1 mL of 6.2 Log10 TCID50/mL of an Italian field isolate of BTV serotype 2, while the remaining 8 vaccinated and 8 unvaccinated animals were challenged by 1 mL of 6.2 Log10 TCID50/mL of an Italian field isolate of BTV serotype 4. Three additional calves were included in the study and used as sentinels to confirm that no BTV was circulating locally. At the time of the challenge, only one vaccinated animal did not have neutralizing antibodies against BTV-4, while the remaining 15 showed titres of at least 1:10 for either BTV-2 or BTV-4. However, the BTV-2 component of the inactivated vaccine elicited a stronger immune response in terms of both the number of virus neutralization (VN) positive animals and antibody titres. After challenge, no animal showed signs of disease. Similarly, none of the vaccinated animals developed detectable viraemia while bluetongue virus serotype 2 and 4 titres were detected in the circulating blood of all unvaccinated animals, commencing on day 3 post-challenge and lasting 16 days. It is concluded that administration of the bivalent BTV-2 and BTV-4 inactivated vaccine resulted in a complete prevention of detectable viraemia in all calves when challenged with high doses of BTV-2 or BTV-4.

Clinical, humoral and IFNgamma responses of cattle to infection with Mycoplasma mycoides var. mycoides small colony and attempts to condition the pathogenesis of the infection.

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides var. mycoides small colony (MmmSC), is one of the most important diseases of cattle in Africa. The role of innate or acquired cell mediated and humoral immunity in conferring protection against MmmSC infection has not yet been elucidated. On the other hand, the pathological lesions caused by the aetiological agent have been considered indicative of an immunopathological process. In this study ten naïve cattle were exposed to in-contact infection with animals infected by intubation with a strain of MmmSC. Clinical signs, antibody response, IFNgamma release and pathological changes at necropsy were analysed and compared with the events following in-contact infection of an equal number of animals kept under daily treatment with cyclosporine for the entire observation period of 84 days. Cyclosporine is a suppressor of the immune response related to the T-cell system. Under the conditions of the experiment, cyclosporine appeared to condition the pathogenesis of CBPP by delaying the events that follow infection, bringing further support to the possibility that the immune response may have an impact on the disease outcome.

The concept of compartmentalisation.

The rationale for establishing trade 'regions' and 'zones' is based on principles of epidemiological science and risk analysis that assess and manage animal disease risks so that the safety of trade can be ensured. However, the boundaries of geographical regions and zones may readily be breached through numerous epidemiological pathways. The concept of a 'compartment' extends the application of a 'risk boundary' beyond that of a geographical interface and considers all epidemiological factors that can contribute to the creation of an effective boundary. The fundamental requirement for application of either concept (regions/zones or compartments) is that the population considered for trade is maintained within management or geographical boundaries which allow clear epidemiological differentiation to be made between those animals and surrounding populations of higher risk. Seven factors are presented that an exporting country might use to guide the identification and documentation of a compartment. Additionally, the steps that would be undertaken to implement trade based on the compartmentalisation concept are discussed.

Investigating on a foodborne outbreak: analysis of the critical points.

The Authors describe an epidemiological survey performed after a cluster of cases of foodborne infection involving several participants at a wedding reception. The aim was to identify the food, the responsible pathogen and any shortcomings in the coordination between the various services and the territorial operating units involved in the outbreak investigation. The investigation involved 149 participants; fifty seven persons (38.3%) had a foodborne illness. The only food item that remained associated with illness after multiple regression analysis was the ricotta cheese (RR 3.58, I.C. 1.,72-7.48 ). The finding of B. cereus in samples of ricotta cheese collected at the dairy food supplier indicate its responsibility for the outbreak but diagnostic certainty could not be achieved as no leftovers were available. Thus, shortcomings in this epidemiological investigation are constituted by: delayed notification, which prevented the acquisition of food samples, lack of a reference laboratory and lack of a specific diagnostic protocols, which prevented the microbiological research for the rapid identification of new pathogens incriminated in foodborne diseases. Finally, environmental and sanitary inspections showed deficiencies in the hygienic measures of food storage, particularly regarding refrigeration and in the HACCP plan that was not properly implemented.

Human exposure to dioxins through diet in Italy.

We have measured the content of polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (together defined as "dioxins") in 269 samples of food of animal origin collected through the regional veterinary services, covering the national territory. Quantification of the dioxins was accomplished by isotope dilution method, and toxic equivalents (TEQ) were calculated. The average daily food intake was obtained from two main sources: national data collected by the National Institute of Nutrition, and data from an ongoing cohort study on diet and cancer including 40,000 Italian subjects. The mean value of dioxins measured in food of animal origin was 0.144 +/- 0.266 pg-TEQ/g (range: 0.003-1.655 pg-TEQ/g). Fish was the item with the highest content. The estimated intake of dioxins with main food items of animal origin is presented. The major contribution to dioxins intake with food comes from cow milk and fish consumption. These results are in agreement with what observed in studies conducted in other countries, such as Germany, Finland, Japan, Spain, and are below the limits set by the European legislation.

Global perspectives on animal welfare: Europe.

Effective implementation and enforcement of legislation is essential to ensure animal welfare. In the World Organisation for Animal Health (OIE) European Region the well-established body of national and European Union laws in existence is growing continuously. The growth is due to various factors, such as new technology in animal farming and experimentation, exploitation of wildlife, new understanding of animal needs, and increasing public awareness and concern. The latter, in particular, determines the need for new animal welfare legislation to regulate and discipline the 'use' of animals for different purposes, such as food production, companionship, work and leisure. This paper intends to provide an overview of the more relevant activities carried out by the Council of Europe and the European Union in the field of animal welfare. The authors identify eLearning as a tool to harmonise the interpretation and the implementation of animal welfare legislation.

Bluetongue virus isolations from midges belonging to the Obsoletus complex (Culicoides, Diptera: Ceratopogonidae) in Italy.

Between July and September 2002 there were outbreaks of bluetongue on three sheep holdings in the communities of San Gregorio Magno (Salerno, Campania), Laviano (Salerno, Campania) and Carpino (Foggia, Puglia), and the involvement of bluetongue virus (btv) was confirmed serologically and virologically. The mortality rate was at least 11 per cent and involved btv serotype 2 (btv-2) and serotype 9 (btv-9). These holdings were also surveyed for the Culicoides (Diptera: Ceratopogonidae) vectors; approximately 10,000 midges belonging to 15 species were captured, but they did not include a single specimen of the classical Afro-Asiatic bluetongue vector, Culicoides imicola. Species belonging to the Obsoletus complex dominated the light-trap collections, and Culicoides obsoletus Meigen, Culicoides scoticus Downes and Kettle and Culicoides dewulfi Goetghebuer constituted 90 per cent of all the Culicoides species captured. Fifty-six pools of the Obsoletus complex (excluding C dewulfi), each containing 100 individual midges and containing only parous and gravid females, were assayed for virus. btv-2 was isolated from three pools from San Gregorio Magno and Carpino, and btv-9 was isolated from one pool from Laviano. These results indicate that a species other than C imicola is involved in the current re-emergence of bluetongue in the Mediterranean Basin, but whether it is C obsoletus sensu stricto or C scoticus, or both, is uncertain.

Characterisation of Aujeszky's disease viruses isolated from domestic animals and from a wild boar (Sus scrofa) in Italy between 1972 and 1995.

Following the isolation of a group I Aujeszky's disease virus from a wild boar in 1993, an investigation was carried out on 30 Italian Aujeszky's disease viruses (ADV's), isolated over a 23-yr period in 12 Italian regions, by means of restriction endonuclease analysis. All strains isolated between 1972 and 1984 belong to group I. From 1984 onwards group II isolates (II and II intermediate) replace group I isolates. The isolation of a group I virus in 1993 from a wild boar supports the hypothesis that ADV's may persist for several years in wild boar populations and that wild boars should therefore be considered reservoirs of Aujeszky's disease virus.

Antibody response and antigen-specific gamma-interferon profiles of vaccinated and unvaccinated pregnant sheep experimentally infected with Brucella melitensis.

It is well known that the immune response in sheep against Brucella melitensis is subject to individual variation, depending on diverse factors. It bears asking whether these factors (e.g. clinical disease, active infection, state of previous immunity), when affecting a group, can cause variation in the performance of different diagnostic tests. To clarify some of the circumstances in which this immune response can vary, we examine the immune-response profile of sheep protected against the clinical disease by prior vaccination with strain Rev. 1 in comparison with the profile of unprotected females showing the classical brucellosis symptoms. An experimental infection was provoked at midpregnancy under controlled conditions of both non-vaccinated (n=7) and previously Rev.1-vaccinated ewes (n=5). Their immune response was monitored from 7 to 9 weeks before abortion or normal birth to 30 weeks afterwards. Antibody response was assessed by classical tests (Rose Bengal test, complement fixation test (CFT)) in comparison with other diagnostic tests (indirect ELISA (iELISA), competitive ELISA (cELISA), fluorescence polarization assay (FPA), immunocapture test (ICT)). In addition, the cell-mediated immune response was indirectly evaluated by the in vitro antigen-specific release of gamma-interferon. The antibody levels and antigen-specific gamma-IFN profile of the non-vaccinated ewes having the disease and excreting the pathogen was notably high and differed significantly (P<0.05 or P<0.01) from those of vaccinated ewes that neither contracted brucellosis nor excreted the pathogen. In general, all the tests detect the infection in the non-vaccinated ewes with substantial effectiveness. It can be concluded that the high levels of circulating antibodies and of antigen-specific gamma-IFN are related to active Brucella infection. Similarly, the state of protection against the disease, but not necessarily against infection, due to a previous immunization with the Rev. 1 vaccination, appears to be responsible for a low level of detectable immune response. Nevertheless, the design of the study limits conclusions to pregnant ewes and cannot be extrapolated to non-pregnant ewes or rams. Likewise, the study provides no information on animals which are carriers of B. melitensis.

A summary of antibody titration experiments in some animal species treated with ERA vaccine and an inactivated rabies vaccine.

The results of antibody titrations in different animal species vaccinated against rabies are reported. The following points are considered: (1) antibody titration may be used to detect an immunity status in dogs, (2) equines should be vaccinated in infected areas, (3) experiments in progress are comparing ERA vaccine and an inactivated vaccine in bovines, and (4) the vaccination of fallow deer (Dama dama) and moufflons (Ovis ammon musimon) produced results suggesting an extension of the experiment with the purpose of vaccinating wild ruminants whenever possible.

Vaccination in the control strategy of bluetongue in Italy.

The incursion of bluetongue (BT) in Italy, in August 2000, caused heavy economic losses, partly due to the direct effect of the disease on the animals, but mostly due to indirect losses due to ruminant movement restrictions conducive to heavy losses to the cattle and sheep industry. To limit losses due to both disease and virus circulation, which was the cause of movement restrictions, the Italian Ministry of Health in May 2001 ordered the vaccination of animals of all domestic ruminant species in infected and "at risk" areas. The vaccination strategy derived from a risk assessment that suggested that the vaccination of all domestic ruminants could reduce both direct losses and virus circulation significantly. The different levels of vaccination coverage, achieved in the various regions of Italy, had clear consequences on the spread of both disease and infection. In regions where more than 80% of the target populations were vaccinated properly, the disease disappeared almost completely and virus circulation was significantly reduced, as documented by the serological surveillance system, after a single vaccination cycle. This led to a significant decrease in the areas subject to movement restrictions. Data generated by both field and controlled experiments contributed to modify the EU approach to BT and to some of the conclusions of the Third OIE International Symposium on Bluetongue that will probably lead to a modification of the Office International des Epizooties (OIE) standard.

Quality assurance in veterinary diagnostic laboratories.

The authors discuss the responsibility of veterinary diagnostic laboratories as suppliers of analytical data for tests on animals and animal products. The guarantee of the quality of analytical data is a basic quality requirement for veterinary certification. It is therefore important for the laboratory to adopt operational quality assurance standards which are recognised internationally. The management and quality assurance criteria contained in the International Standardisation Organisation/International Electrotechnical Commission Guide 25, or in directives or guidelines established by international organisations such as the Office International des Epizooties and the Codex Alimentarius of the Food and Agriculture Organisation, are reviewed. These documents provide procedures for adopting the principles of quality assurance in order to acquire the recognition of competence to execute the laboratory tests required for national and international veterinary certification.

Import risk analysis: the experience of Italy.

The authors propose a contribution to the possible revision of Chapters 1.4.1. and 1.4.2. of the International Animal Health Code (Code) of the Office International des Epizooties (OIE). In particular, data are presented to illustrate some of the inadequacies of both the rationale and the results of the method for risk assessment reported in the Code. The method suggested by the Code for risk assessment is based on the calculation of the 'probability of the occurrence of at least one outbreak' of a given disease following the importation of a given quantity of either live animals or animal products (unrestricted risk estimate). This is usually undertaken when dealing with rare events. For a country such as Italy, this method may not be particularly useful as the frequency of disease outbreaks is what should be estimated, so as to provide decision makers with appropriate and relevant information. Practical use of risk information generated by the use of the OIE risk assessment method for swine vesicular disease (SVD) would have encouraged the Chief Veterinary Officer of Italy to prohibit all imports of swine from the Netherlands and Belgium for at least two years in the early 1990s, with the consequential heavy economic losses for both Italy and the exporting countries. On the contrary, the number of actual outbreaks of the disease due to direct imports of swine from Member States of the European Union (EU), which occurred in Italy in 1992, 1993 and 1994 was very low (two to five outbreaks due to direct imports of swine from the Netherlands and one to two from Belgium). An example of a method for assessing the risks associated with high volumes of trade in commodities is also described. This method is based on the Monte Carlo simulation and provides the information required to evaluate the costs of the strategies compared. The method can be used to predict the number of outbreaks which are likely to occur following importation and enables a comparison to be made of alternative safeguards. This would lead to the selection of the most cost-effective one. The comparison is conducted using risk curves and allows a quantitative evaluation and comparison to be made of various scenarios, varying from an absence of safeguards to combinations of various safeguards.

Spatial risk factors related to outbreaks of contagious bovine pleuropneumonia in northern Italy (1990-1993).

In October 1990, an outbreak of contagious bovine pleuropneumonia (CBPP) was reported in Italy after an absence of approximately one century. Since October 1990, ninety-four outbreaks have occurred in Italy, of which forty-seven were concentrated in three areas of northern Italy (Lombardy region). The disease was eradicated in September 1993. The data used for the analysis were obtained from the epidemiological investigations undertaken during the outbreaks of 1990-1993. The unit of interest for the analysis is the farm. Spatial segregation of infected and uninfected farms within the study area was determined through the Pielou index of segregation. Data from herds within the same set of outbreaks were analysed through logistic regression to identify factors which could be used to discriminate between infected and uninfected herds. The study indicated a clear spatial segregation between infected and uninfected herds. The results of the analysis do not indicate the mode of disease spread. However, the study demonstrated that both aerosol and indirect transmission of the infection could have occurred, as previously documented in Africa. The possibility that indirect transmission played a prominent role in the spread of CBPP in the region of Lombardy is a completely new suggestion. Further studies are required to understand the epidemiology of CBPP in regions with intensive farming and a relatively cold climate. In particular, three aspects require consideration; firstly, animal movement among neighbouring herds could produce a pattern of disease similar to the one produced by indirect transmission (this possibility was excluded in the epidemiological outbreak investigations conducted by field veterinarians). Secondly, the methods of spatial analysis used in this study have not been previously used in the field of veterinary epidemiology. Further validation of the efficacy of these methods is thus required. Thirdly, the epidemiology of CBPP under conditions of high animal density and a relatively cool climate, as encountered in Lombardy, requires further investigation.

Sensitivity and specificity of serological and bacteriological tests for contagious bovine pleuropneumonia.

In 1990 an outbreak of contagious bovine pleuropneumonia (CBPP) occurred in Italy. Subsequent surveillance for CBPP was based on random sampling in bovine herds, serological controls on all animals moved from the herd of origin and controls on slaughtered animals. Official tests employed were the complement fixation test (CFT) and bacteriological isolation and typing. A total of 33,856 serum samples collected from herds in CBPP-free regions were used to define CFT specificity, while samples from 595 animals from infected herds were employed to define the sensitivity. Ninety-nine animals from three infected herds were used to estimate the sensitivity of the isolation technique. Results showed the specificity of CFT (threshold +1:10) to be 98% and sensitivity to be 63.79%. The sensitivity of the test did not change significantly, regardless of whether the lesions were caused by acute or chronic infection. The sensitivity of the isolation technique was 54.1%.

Quality assurance of veterinary services at the international level: a proposed approach.

A proposal for the harmonization of quality assurance of Veterinary Services at the international level is made. This proposal is based on the hypothesis of accreditation of Veterinary Services according to the 9000 series of the International Standards Organisation (ISO) standards. An example of a way in which ISO 9000 standards can be used within the context of management of Veterinary Services is given, together with an explanation of the possible role of the Office International des Epizooties in ensuring fairness of evaluations of Veterinary Services at the international level.

Importance of the traceability of animals and animal products in epidemiology.

Traceability of animals and animal products has become a priority for governments of the developed countries, due to consumer demand for comprehensive and integrated food safety policies. In addition to analysing the differences between traceback and traceability systems, the authors describe some applications of animal traceback systems and the principal characteristics of an animal identification and registration system. The importance of a traceability system for food-borne risk assessment and management, and the most recent approaches towards a comprehensive and integrated animal health and food safety policy are reported.