Evaluation of the cost-effectiveness of bovine brucellosis surveillance in a disease-free country using stochastic scenario tree modelling.

Surveillance systems of exotic infectious diseases aim to ensure transparency about the country-specific animal disease situation (i.e. demonstrate disease freedom) and to identify any introductions. In a context of decreasing resources, evaluation of surveillance efficiency is essential to help stakeholders make relevant decisions about prioritization of measures and funding allocation. This study evaluated the efficiency (sensitivity related to cost) of the French bovine brucellosis surveillance system using stochastic scenario tree models. Cattle herds were categorized into three risk groups based on the annual number of purchases, given that trading is considered as the main route of brucellosis introduction in cattle herds. The sensitivity in detecting the disease and the costs of the current surveillance system, which includes clinical (abortion) surveillance, programmed serological testing and introduction controls, were compared to those of 19 alternative surveillance scenarios. Surveillance costs included veterinary fees and laboratory analyses. The sensitivity over a year of the current surveillance system was predicted to be 91±7% at a design prevalence of 0.01% for a total cost of 14.9±1.8 million €. Several alternative surveillance scenarios, based on clinical surveillance and random or risk-based serological screening in a sample (20%) of the population, were predicted to be at least as sensitive but for a lower cost. Such changes would reduce whole surveillance costs by 20 to 61% annually, and the costs for farmers only would be decreased from about 12.0 million € presently to 5.3-9.0 million € (i.e. 25-56% decrease). Besides, fostering the evolution of the surveillance system in one of these directions would be in agreement with the European regulations and farmers perceptions on brucellosis risk and surveillance.

Tuberculosis, Brucellosis and Leucosis in Cattle: A Cost Description of Eradication Programmes in the Region of Lazio, Italy.

The eradication of tuberculosis, brucellosis and leucosis in cattle has not yet been achieved in the entire Italian territory. The region of Lazio, Central Italy, represents an interesting case study to evaluate the evolution of costs for these eradication programmes, as in some provinces the eradication has been officially achieved, in some others the prevalence has been close to zero for years, and in still others disease outbreaks have been continuously reported. The objectives of this study were i) to describe the costs for the eradication programmes for tuberculosis, brucellosis and leucosis in cattle carried out in Lazio between 2007 and 2011, ii) to calculate the ratio between the financial contribution of the European Union (EU) for the eradication programmes and the estimated total costs and iii) to estimate the potential savings that can be made when a province gains the certification of freedom from disease. For the i) and ii) objectives, data were collected from official sources and a costing procedure was applied from the perspective of the Regional Health Service. For the iii) objective, a Bayesian AR(1) regression was used to evaluate the average percentage reduction in costs for a province that gained the certification. The total cost for the eradication programmes adjusted for inflation to 1 January 2016 was estimated at 18 919 797 euro (5th and 95th percentiles of the distribution: 18 325 050-19 552 080 euro). When a province gained the certification of freedom from disease, costs decreased on average by (median of the posterior distribution) 47.5%, 54.5% and 54.9% for the eradication programmes of tuberculosis, brucellosis and leucosis, respectively. Information on possible savings from the reduction of control costs can help policy makers operating under budget constraints to justify the use of additional resources for the final phase of eradication.

Risk assessment and management of brucellosis in the southern greater Yellowstone area (II): Cost-benefit analysis of reducing elk brucellosis prevalence.

Recent cases of bovine brucellosis (Brucella abortus) in cattle (Bos taurus) and domestic bison (Bison bison) of the southern Greater Yellowstone Area (SGYA) have been traced back to free-ranging elk (Cervus elaphus). Several management activities have been implemented to reduce brucellosis seroprevalence in elk, including test-and-slaughter, low-density feeding at elk winter feedgrounds, and elk vaccination. It is unclear which of these activities are most cost-effective at reducing the risk of elk transmitting brucellosis to cattle. In a companion paper, a stochastic risk model was used to translate a reduction in elk seroprevalence to a reduction in the risk of transmission to cattle. Here, we use those results to estimate the expected economic benefits and costs of reducing seroprevalence in elk using three different management activities: vaccination of elk with Brucella strain 19 (S19), low-density feeding of elk, and elk test-and-slaughter. Results indicate that the three elk management activities yield negative expected net benefits, ranging from -$2983 per year for low-density feeding to -$595,471 per year for test-and-slaughter. Society's risk preferences will determine whether strategies that generate small negative net benefit, such as low-density feeding, are worth implementing. However, activities with large negative net benefits, such as test-and-slaughter and S19 vaccination, are unlikely to be economically worthwhile. Given uncertainty about various model parameters, we identify some circumstances in which individual management activities might generate positive expected net benefit.

Economic analysis of vaccination to control bovine brucellosis in the States of Sao Paulo and Mato Grosso, Brazil.

Brucellosis is a zoonotic disease that causes important economic losses in Brazil, and the country has therefore established a national program for its control and eradication. Using data generated in the last national brucellosis survey, we conducted an economic analysis in two Brazilian States with different brucellosis status, Mato Grosso (with high prevalence) and Sao Paulo (with low prevalence). The economic analysis was based on the calculation of the additional benefits and costs of controlling bovine brucellosis through the vaccination of heifers aged between 3 and 8 months with S19 vaccine, considering maximal and minimal impacts of the disease. The analysis showed that vaccinating 90% of the replacement heifers aged 3-8 months of age offers the best economic performance in a vaccination program against bovine brucellosis if compared to vaccination rates of 70% and 80%. Moreover, regions with higher prevalences of bovine brucellosis would experience significant economic advantages when implementing a vaccination strategy to control the disease. This economic analysis will allow decision makers to plan more economically effective vaccination programs.

Serological diagnosis of bovine brucellosis: a review of test performance and cost comparison.

The authors reviewed over 50 publications in which the sensitivity and specificity values of assays used for the detection of exposure to Brucella abortus had been examined. The sum of the sensitivity and specificity values for each test was averaged to give a performance index (PI) and allow for a comparison between the different methodologies. A score of 200 was perfect. Based on the PI, the buffered antigen plate agglutination test (BPAT) rated highest (PI = 193.1) among the conventional tests. This indicates better accuracy than the other conventional tests including the Rose Bengal test (PI = 167.6) and the complement fixation test (PI = 172.5). Overall, the primary binding assays, including the fluorescence polarisation assay (PI = 196.4), the indirect enzyme-linked immunosorbent assay (PI = 189.8) and the competitive enzyme-linked immunosorbent assay (PI = 188.2), were more accurate than the conventional tests, except for the BPAT. In addition, a fee comparison suggested that the primary binding tests were price competitive with conventional tests for the diagnosis of brucellosis and, therefore, had a better combined cost/efficiency rating.

[Epidemiologic surveillance and prevention of brucellosis in ruminants: the example of the north African region and the Near East]. / Surveillance épidémiologique et prophylaxie de la brucellose des ruminants: l'exemple de la région Afrique du Nord et Proche-Orient.

The author reviews the general principles and different strategies recommended for the epidemiological surveillance and control of brucellosis in cattle and small ruminants, with particular reference to the region of North Africa and the Near East. Three strategic options are proposed, the choice of which depends on the real prevalence of the disease, the socio-economic context, the state of advancement of the animal health surveillance system and the policy set by the competent authorities. In heavily infected countries, gradual changeover is recommended from strategy A (systematic vaccination) to strategy B (selective vaccination), and eventually to strategy C (control measures), concurrent with the establishment of an adequate veterinary infrastructure, in particular for epidemiological surveillance and the control of animal movements. The author stresses the relevance for the majority of countries in the region in question of implementing the guidelines drawn up by the Food and Agriculture Organization, the World Health Organization and the Office International des Epizooties to control brucellosis in the Middle East.

Economic evaluation of bovine brucellosis and tuberculosis eradication programmes in a mountain area of Spain.

We applied social cost-benefit analysis to the economic evaluation of the bovine brucellosis and bovine tuberculosis eradication programmes carried out by the public eradication authority for mountain areas in the Spanish Central Pyrenees. We considered only the effects on animal health and production. We also evaluated several hypotheses corresponding to the different sanitary situations of two valleys studied. The results were different for the two disease programmes. The brucellosis programme was economically efficient over a sufficiently long time frame, but the bovine tuberculosis programme was not. A factor having the greatest influence on the economic efficiency of the programmes was the initial prevalence of the disease in the two valleys studied. The greater this was, the more difficult it was to obtain positive net benefits; this was due the initially high compensation paid for the slaughter of animals testing positive for the disease. The relatively small animal health and production returns derived from the tuberculosis programme explained it's failure to generate positive economic results. The fact that the economic evaluation resulted in unfavourable outcomes is not in itself justification for project termination, because the benefits to the wider community through the prevention of zoonosis were not considered in this analysis.

Epidemiologic survey of bovine diseases in Suriname.

A seroepidemiologic survey of cattle diseases was undertaken in Suriname in 1985 to help assess the livestock disease situation in that country. The six diseases covered by the survey were bovine coronavirus infection, bovine rhinotracheitis, bovine virus diarrhea, brucellosis, parainfluenza-3 infection, and respiratory syncytial virus infection. The results indicated relatively low prevalences of these diseases compared to the prevalences found in most developed countries. The reasons for this are uncertain, but the finding suggests that the cattle population in Suriname could lack extensive exposure to these diseases and so could be highly susceptible to them. In addition, the evident need for more thoroughgoing survey data points up the need to establish a continuous animal data health monitoring system in Suriname--as well as in other developing countries where there is a need to objectively assess the livestock disease picture.

Brucellosis: an increasing public health hazard in Uganda.

The paper highlights the importance of brucellosis as a public health hazard and that the disease appears to be on the increase in Uganda. In 5 districts cattle on newly established ranches and farms were blood-tested using ther serum agglutination test. The survey covered 5 ranches and 10 farms. The total number of cattle tested were 1606 and of these 18.1% were positive to the serum agglutination test. Attempts are now being made by the W.H.O. and Uganda Government to study and find out the impact of the disease in both animals and man.