Disease Risk Assessments Involving Companion Animals: an Overview for 15 Selected Pathogens Taking a European Perspective.

Prioritization of companion animal transmissible diseases was performed by the Companion Animals multisectoriaL interprofessionaL Interdisciplinary Strategic Think tank On zoonoses (CALLISTO) project. The project considered diseases occurring in domesticated species commonly kept as pets, such as dogs and cats, but also included diseases occurring in captive wild animals and production animal species. The prioritization process led to the selection of 15 diseases of prime public health relevance, agricultural economic importance, or both. An analysis was made of the current knowledge on the risk of occurrence and transmission of these diseases among companion animals, and from companion animals to man (zoonoses) or to livestock. The literature was scanned for risk assessments for these diseases. Studies were classified as import risk assessments (IRAs) or risk factor analyses (RFAs) in endemic areas. For those pathogens that are absent from Europe, only IRAs were considered; for pathogens present throughout Europe, only RFAs were considered. IRAs were identified for seven of the eight diseases totally or partially absent from Europe. IRAs for classical rabies and alveolar echinococcosis found an increased risk for introduction of the pathogen into officially disease-free areas as a consequence of abandoning national rules and adopting the harmonized EU rules for pet travel. IRAs for leishmaniosis focused on risk associated with the presence of persistently infected dogs in new geographical areas, taking into consideration the risk of disease establishment should a competent vector arise. IRAs for Crimean-Congo haemorrhagic fever and West Nile fever indicated that the likelihood of introduction via companion animals was low. IRAs for bluetongue paid no attention to the risk of introduction via companion animals, which was also the case for IRAs for foot-and-mouth disease, the only disease considered to be absent from Europe. RFAs dealing with the risk factors for companion animals to become infected were identified for eight of the 14 diseases found in Europe or parts of it. RFAs for leptospirosis were most numerous (four studies). The host related risk factor 'age' was identified as significant for dogs in at least two RFAs for cystic echinococcosis and giardiasis. Among husbandry and healthcare related factors, 'eating (uncooked) offal', 'being free roaming' and 'poor deworming practice' were associated with risk for dogs in at least two RFAs for cystic echinococcosis, while 'having received recent veterinary treatment' was identified as a risk factor in at least two studies on infection with extended spectrum beta lactamase-producing bacteria, one in horses and the other in dogs and cats. Finally, although the environmental factors 'season' and 'hydrological density' were identified as significant risk factors for dogs in at least two RFAs for leptospirosis, the inconsistent case definitions used in those studies made comparison of study results problematic. RFAs considering the risk of people becoming infected from companion animals were identified for eight of the 14 diseases found in Europe or parts of it. RFAs for human campylobacteriosis were the most numerous (n = 6). Most studies made an assessment as to whether keeping a pet per se, or keeping a pet with supposed or known risk factors, was a risk factor for people relative to other risks. This allowed some studies to report the population attributable risk or population attributable fraction of the incidence of human disease due to companion animals (for campylobacteriosis, salmonellosis and toxoplasmosis), which is a measure that is easy to perceive for laymen and policy makers. No RFAs were found that dealt with the risk to food animals from companion animals for any of the 15 pathogens investigated. Few risk method-based studies were identified that provided information on risk factors for companion animals and on their role as a source of these 15 selected diseases, indicating a clear knowledge gap. There were not enough assessments for any of the 15 diseases to allow meta-analyses, whether these assessments dealt with companion animal disease risk or companion animal-associated human disease risk. Important method and technology gaps were the lack of harmonization in the case definitions used for a given disease and the lack of good diagnostics allowing pathogen identification to taxonomic levels that are meaningful for risk analysis. Molecular epidemiology studies on zoonotic pathogens, which included companion animals among the potential human risk factors, were not found, although such studies would provide good preliminary insights without requiring any tracing of people or any interviews. In addition to performing further risk studies that take into account these issues, there is a need for responsible pet ownership and continued education of professionals in companion animal zoonoses. Additional risk assessment studies should allow more targeted actions to reduce the risk of zoonotic diseases transferred via companion animals and provide information that will promote risk-awareness in healthy human-animal relationships.

A Transitional Model for the Evaluation of West Nile Virus Transmission in Italy.

In August 2008, after 10 years of apparent silence, West Nile virus (WNV) infection re-emerged in northern Italy, spreading through the territories of three regions. In the following years, new cases occurred in the same area and additional foci of infection were observed in central and southern Italy, involving also Sicily and Sardinia islands. The Italian Ministry of Health ordered to test by RT-PCR all blood and organ donors from 15th June to 15th November of each year in the infected areas. The period at risk of WNV transmission was defined on the basis of literature data, but a more scientific estimation of the transmission season, under Italian circumstances, needs to be performed. A transitional model previously developed by other Authors was applied and adapted to Italian circumstances, to describe and quantify the WNV transmission cycle between birds and mosquitoes. Culex spp. was considered the main vector, and mosquito parameters were adapted to this genus. Magpies (Pica pica) were considered the main bird host. The model was partially validated through the results of the entomological surveys carried out in central Italy and in Po Valley. The results of the transitional model permitted to calculate the basic reproduction number (R0 ) during 2010 for the whole Italian territory at 1 km of spatial resolution, estimating the risk of WNV transmission during the year and creating detailed risk maps for Italy. The mean values of R0 for the whole Italy varied between 0.4 and 4.8, with values >1 from the end of May to the middle of September. The coastal and flat zones of Italy showed the highest R0 values. Although partially validated, the model showed a substantial acceptable capacity of defining the period at major risk of WNV transmission in Italy, helping Public health authorities in the application of appropriate and timely control and preventive measures.

Prioritization of Companion Animal Transmissible Diseases for Policy Intervention in Europe.

A number of papers have been published on the prioritization of transmissible diseases in farm animals and wildlife, based either on semiquantitative or truly quantitative methods, but there is no published literature on the prioritization of transmissible diseases in companion animals. In this study, available epidemiological data for diseases transmissible from companion animals to man were analysed with the aim of developing a procedure suitable for their prioritization within a European framework. A new method and its associated questionnaire and scoring system were designed based on methods described by the World Organisation for Animal Health (OIE). Modifications were applied to allow for the paucity of specific information on companion animal transmissible diseases. The OIE method was also adapted to the subject and to the regional scope of the interprofessional network addressing zoonotic diseases transmitted via companion animals in Europe: the Companion Animals multisectoriaL interprofessionaL Interdisciplinary Strategic Think tank On zoonoses (CALLISTO). Adaptations were made based on information collected from expert groups on viral, bacterial and parasitic diseases using a structured questionnaire, in which all questions were closed-ended. The expert groups were asked to select the most appropriate answer for each question taking into account the relevance and reliability of the data available in the scientific literature. Subsequently, the scoring of the answers obtained for each disease covered by the questionnaire was analysed to obtain two final overall scores, one for human health impact and one for agricultural economic impact. The adapted method was then applied to select the 15 most important pathogens (five for each pathogen group: viral, bacterial and parasitic) on the basis of their overall impact on public health and agriculture. The result of the prioritization exercise was a joint priority list (available at www.callistoproject.eu) of relevant pathogens according to these two criteria. As the scope of CALLISTO was comprehensive in terms of geographical area, animal species involved and impact of the diseases, the list of prioritized diseases had to accommodate the realities in different European countries and the differences in biology and animal-human relationships in a wide range of species including cats and dogs, pet pigs and sheep as well as captive reptiles. The methodology presented in this paper can be used to generate accurate priority lists according to narrower and more specific objectives.

The components of 'One World - One Health' approach.

The interaction between living beings, including men, animals and pathogens, sharing the same environment, should be considered as a unique dynamic system, in which the health of each component is inextricably interconnected and dependent with the others. Nowadays, a new integrated One Health approach is reflecting this interdependence with a holistic view to the ecological system. The One Health approach can be defined as a collaborative and a multidisciplinary effort at local, national and global level to guarantee an optimal healthy status for humans, animals and environment. Strictly related to the One Health concept is to be considered the control of infectious diseases, which have influenced the course of human history. Four different components might be identified as key elements within the 'One World - One Health' (OWOH) approach: the geographical component, the ecological one, the human activities and the food-agricultural ones.

Analysis of surveillance systems in place in European Mediterranean countries for West Nile virus (WNV) and Rift Valley fever (RVF).

West Nile virus (WNV) and Rift Valley fever virus (RVFV) represent an important group of viral agents responsible for vector-borne zoonotic diseases constituting an emerging sanitary threat for the Mediterranean Basin and the neighbouring countries. WNV infection is present in several Mediterranean countries, whereas RVF has never been introduced into Europe, but it is considered a major threat for North African countries. Being vector-borne diseases, they cannot be prevented only through an animal trade control policy. Several approaches are used for the surveillance of WNV and RVFV. With the aim of assessing the surveillance systems in place in Mediterranean countries, two disease-specific questionnaires (WNV, RVFV) have been prepared and submitted to Public Health and Veterinary Authorities of six EU countries. This study presents the information gathered through the questionnaires and describes some critical points in the prevention and surveillance of these diseases as emerged by the answers received.

The clinical role of contrast-enhanced ultrasound in the evaluation of renal artery stenosis and diagnostic superiority as compared to traditional echo-color-Doppler flow imaging.

AIM: The purpose of this study was to investigate the feasibility of contrast-enhanced ultrasound (CEUS) in the evaluation of renal artery stenosis as compared with traditional techniques: echo color Doppler (ECD) investigation and selective angiography .CEUS is a technique based on the injection of an intravascular biocompatible tracer, namely an intravenous contrast galactose microparticle suspension containing microbubbles (Levovist), that has a similar rheology to that of red blood cells, allowing quantification of renal tissue perfusion. METHODS: A population of 120 hypertensive patients (82 men, mean age 55) with a systolic abdominal murmur and/or a diagnosis of poly-districtual atherosclerosis was studied by ECD and CEUS (Levovist). Selective angiography was performed in patients with renal artery stenosis demonstrated by one of the two ultrasonographic techniques. RESULTS: Forty of the 120 patients in the study population showed renal artery stenosis at one of the two ultrasound techniques: ECD identified renal artery stenosis in 33 cases and CEUS in 38. Instead, selective angiography had detected renal artery stenosis in 38 patients, the same with renal artery stenosis diagnosed by CEUS. Thus, CEUS sensitivity, specificity and accuracy were similar to those of angiography while six false negatives and two false positives were obtained with ECD. CONCLUSION: Our results suggest that this renal CEUS is a promising, new, non-invasive method for screening patients with suspected renal artery stenosis. This technique appears to be superior to traditional ECD flow imaging for diagnosing renal artery stenosis and so may be an important aid in cardiovascular diagnostics.