Preparedness for emerging infectious diseases: pathways from anticipation to action.

Emerging and re-emerging infectious disease (EID) events can have devastating human, animal and environmental health impacts. The emergence of EIDs has been associated with interconnected economic, social and environmental changes. Understanding these changes is crucial for EID preparedness and subsequent prevention and control of EID events. The aim of this review is to describe tools currently available for identification, prioritization and investigation of EIDs impacting human and animal health, and how these might be integrated into a systematic approach for directing EID preparedness. Environmental scanning, foresight programmes, horizon scanning and surveillance are used to collect and assess information for rapidly responding to EIDs and to anticipate drivers of emergence for mitigating future EID impacts. Prioritization of EIDs - using transparent and repeatable methods - based on disease impacts and the importance of those impacts to decision-makers can then be used for more efficient resource allocation for prevention and control. Risk assessment and simulation modelling methods assess the likelihood of EIDs occurring, define impact and identify mitigation strategies. Each of these tools has a role to play individually; however, we propose integration of these tools into a framework that enhances the development of tactical and strategic plans for emerging risk preparedness.

One Health in a world with climate change.

The One Health movement, as defined in this paper, has progressed from a focus on emerging infectious diseases to a broader set of challenges that include food security and food safety. These interact with climate change, a so-called 'wicked problem' that has links to all human activity. Climate change acts as a threat multiplier that interacts both directly and indirectly with variables, such as disease, food production, food security, food safety and poverty. A number of these interactions are briefly described in this paper before issues of complexity and interconnectedness between these variables are discussed. A common thread underpinning this current global challenge to civilisation is that the system is now dominated by the activities of humans--and many scientists label the current epoch the 'Anthropocene'. Specifically, humans have for the first time collectively overloaded the Earth's capacity to supply, absorb, replenish and stabilise. Many scientists now observe that the ecological and environmental foundations of civilisation appear to be at risk. This paper suggests that, for the One Health movement to address such challenges, the range and number of disciplines that need to be involved must be expanded. In particular, in addition to the insights provided by technical specialists, we need to engage disciplines with the capacity to advance political, economic and social reforms. This will not be easy, but it is argued that this is what is required from the One Health movement in a world with climate change.

Good governance of animal health systems and public-private partnerships: an Australian case study.

The animal health system in Australia has evolved over more than 100 years and includes innovative public-private partnership arrangements. The establishment in 1996 of Animal Health Australia (AHA), a not-for-profit company, was a crucial development which formalised arrangements for shared decision-making and funding across both government and industry stakeholders. However, Federal and State governments retain legislative authority for animal health control. Accordingly, all programmes must recognise that the public sector remains an executive arm of government, accountable for its actions. Hence, much effort has been invested in ensuring that the governance arrangements within AHA are lawful and transparent. The Emergency Animal Disease Response Agreement (EADRA) is a very good example of governance arrangements that are sustainably financed, widely available, provided efficiently, without waste or duplication, and in a manner that is transparent and free of fraud or corruption. The benefits of EADRA include certainty and greater transparency of funding; greater efficiency through increased probability of a rapid response to an occurrence of any of 65 diseases; and industry participation in the management and financing of such a response.

Managing animal disease risk in Australia: the impact of climate change.

Climate change is one of a number of factors that are likely to affect the future of Australian agriculture, animal production and animal health, particularly when associated with other factors such as environmental degradation, intensive animal production, an increasing human population, and expanding urbanisation. Notwithstanding the harshness and variability of Australia's climate, significant livestock industries have been developed, with the majority of products from such industries exported throughout the world. A critical factor in achieving market access has been an enviable animal health status, which is underpinned by first class animal health services with a strong legislative basis, well-trained staff, engagement of industry, effective surveillance, good scientific and laboratory support, effective emergency management procedures, a sound quarantine system, and strong political support. However, enhancements still need to be made to Australia's animal health system, for example: re-defining the science-policy interface; refining foresight, risk analysis, surveillance, diagnostics, and emergency management; improving approaches to education, training, technology transfer, communications and awareness; and engaging more with the international community in areas such as capacity building, the development of veterinary services, and disease response systems. A 'one health' approach will be adopted to bring together skills in the fields of animal, public, wildlife and environmental health. These initiatives, if managed correctly, will minimise the risks resulting from global warming and other factors predisposing to disease.

A seroepidemiological study of bovine pestivirus in Queensland beef and dairy herds conducted in 1994/95.

OBJECTIVE: To describe the distribution and prevalence of cattle herds with detectable antibody to bovine pestivirus in Queensland in 1994/95. MATERIALS AND METHODS: The study used 7,838 serum samples collected from 250 herds in Queensland, as part of a structured animal health surveillance program conducted in 1994 and 1995. Samples were collected from female cattle bred on the property. In each herd, 10 to 20 heifers less than two years of age and 10 to 15 older cows were sampled giving a 95% probability of detecting one or more seropositive animals if the seroprevalence was approximately 10% or greater. Sera were analysed for antibodies to bovine pestivirus using a virus neutralisation test. RESULTS: Total cattle numbers in sampled herds varied from 62 to 24,600 head, while total area of properties sampled varied from 50 to 395,400 hectares. Eleven percent of herds contained no seropositive animals among those sampled, and in 38% of herds, all sampled cattle aged one to two years of age were seronegative. There was a trend for larger herds to have one or more animals seropositive for bovine pestivirus (chi-squared for Linear trend = 3.656, p = 0.056). Herds with more than 500 head of cattle were significantly more likely than herds with less than 500 head to contain one or more seropositive animals in any age group (prevalence ratio = 1.12; 95% confidence interval 1.01 - 1.23; p = 0.026). Age specific seroprevalence increased from around 10% in heifers, to between 75% and 85% in cows aged 10 years. The average annual incidence risk for bovine pestivirus infection varied from 0.12 to 0.24 seroconversions per cattle year at risk, and did not vary with age. The overall crude seroprevalence adjusted for herd size was 45%. There was a wide range of seroprevalence recorded for each level of stocking intensity. CONCLUSIONS: This survey provides valuable baseline data on bovine pestivirus infection in Queensland cattle herds.

Serological examination for evidence of infection with Hendra and Nipah viruses in Queensland piggeries.

OBJECTIVE: To examine piggeries in Queensland for evidence of infection with Hendra virus and Nipah virus. DESIGN: A serological survey was designed to provide 99% confidence of detecting at least one infected pig herd in Queensland, assuming that for each virus, at least 5% of herds would have been exposed to virus and that at least 40% of the finisher pigs in these herds would have detectable antibodies to virus. PROCEDURE: A two stage sampling regimen was used. All samples were tested with serum neutralisation tests developed and performed at the Australian Animal Health Laboratory. RESULTS: There was no evidence of antibody to either virus in the 500 samples collected from 100 herds. CONCLUSION: The results of the survey support a case that commercial pigs in Queensland are free of both Hendra virus and Nipah virus infections.

Prevalence of antibodies of Leptospira serovars in beef cattle in central Queensland.

OBJECTIVE: To obtain up-to-date data on the prevalence of antibodies to Leptospira serovars in central Queensland beef herds preliminary to assessing their role in bovine subfertility and the role of cattle as a zoonotic reservoir. DESIGN: Sera from 2857 female cattle in 68 central Queensland beef herds were tested for antibodies to 14 Leptospira serovars using the microscopic agglutination test. Vaccination use and age of cattle were collected to enable the calculation of crude and age-stratified seroprevalences. RESULTS: The most commonly detected antibodies were to serovars hardjo (15.8% crude seroprevalence), tarassovi (13.9%), pomona (4.0%) and szwajizak (2.2%). Vaccinates were omitted from the hardjo and pomona seroprevalence data. The seroprevalence for hardjo and pomona tended to increase with age of the animals. CONCLUSION: These results are broadly similar to those of previous serological surveys. The data suggest that serovars other than hardjo, pomona and tarassovi, are unlikely to have a significant role in bovine subfertility and that cattle are unlikely to be a source of human infection with them in central Queensland.

A study of pathology of a bovine primary peripheral myelinopathy with features of tomaculous neuropathy.

Cases of a bovine neuropathy are reported in which peripheral nerves show "sausage-shaped" thickenings of the myelin sheaths at different sites of the internode. Clinical signs of dysphagia and chronic rumenal bloat developed after weaning which were attributable to bilateral vagus nerve degeneration. Trunks of the sciatic nerves and brachial plexuses were similarly affected with the animal adopting a weak shuffling gait. Affected animals were the progeny of sire-daughter matings. The lesions are similar to those seen in the tomaculous neuropathies of man. The present study is believed to be the first report of this lesion occurring in domestic animals.