Risk Factors for Brucella spp. in Domestic and Wild Animals

Brucella spp. is the aetiological agent of brucellosis, a serious contagious disease that results in reproductive failure and that has profound public health significance because of its zoonotic characteristics. This disease also is responsible for a high economic impact associated with the application of prevention, surveillance and test-and-slaughter programmes in animals by national authorities. Brucella spp. infects a large variety of animals and their prevalence is variable worldwide, mainly associated with the presence or absence of control programmes and also with the vaccination of animals against brucellosis. To achieve the control and eradication of brucellosis, the identification of the risk factors of brucellosis that maintain the infection in animals and/or the environment is fundamental. Although several risks have been identified, the most important have been associated with the biology of the bacteria, animal management (age, sex, species or breed), herd management (herd/flock size, number of species, contact with wild animals or type of animal production), farm management (facilities, cleaning and disinfection or veterinary support) and farmers’ knowledge about the disease. Thus, to benefit from proper risk identification of brucellosis, it is essential to put a cost-effective and efficient brucellosis control programme into place

Cost-benefit analysis of sheep and goat brucellosis vaccination with Rev.1 in the North of Portugal from 2000 to 2005

In the North of Portugal, a mass vaccination programme of small ruminants was conducted from 2001 to 2004. A study of cost-benefit was carried out for the 2000/2005 period to ascertain the economic benefits of this strategy. In order to estimate the cost of the zoonosis, the compensation costs paid to farmers for culled animals in the Brucellosis Eradication Campaign, data from vaccine Rev. 1 costs, and costs of people internment due to brucellosis were studied. An increase in the cost was observed from 2000 to 2001 (aproximately US$110,000), essentially due to compensation for culled animals, but also from vaccination and human internment costs. However, a progressive decrease was observed from 2001 to 2004 (from more than US$1,200,000 in 2001 to US$180,000 in 2004), roughly US$ 1,020,000 less. As the main conclusion, the annual cost of this zoonosis decreased by an average of almost US$600,000 per year, and a total of more than three million dollars were saved from 2000 to 2005. The results of this study suggest that mass vaccination with Rev. 1 reduced overall costs and was effective in reducing animal and human brucellosis costs

Comparison of two techniques of isolation of Mycobacterium avium subsp. paratuberculosis in faecal samples of ovine with clinical suspicion of paratuberculosis

A paratuberculose é uma enterite crônica granulomatosa causada por Mycobacterium avium subsp. paratuberculosis que afeta principalmente os ruminantes. A cultura de bactérias a partir de amostras de fezes e tecidos constitui um dos métodos mais eficazes de diagnóstico, sendo ainda o único método disponível para obtenção de isolamentos e estirpes de micobactérias. Contudo, este método apresenta baixa sensibilidade e requer meses de incubação antes do crescimento de colônias. Neste estudo, utilizou-se a cultura fecal como método de diagnóstico em ovinos de diferentes raças portuguesas, com sinais compatíveis com a doença. Fez-se ainda a comparação entre os meios de cultura Löwenstein Jensen® com micobactina®J e o de Middlebrook® 7H11 com OADC®, utilizados no isolamento da bactéria. As percentagens de isolamento em cada um os meios foram de 2,0% (6/300) para Löwenstein Jensen® com micobactina J e 1,0% (3/300) para Middlebrook® 7H11/OADC. As três amostras positivas no meio de Middlebrook® 7H11/OADC também foram positivas no meio de Löwenstein Jensen®com micobactina J e nenhuma foi somente positiva no meio de Middlebrook®7H11/OADC. Os resultados deste estudo sugerem que o meio de Löwenstein-Jensen®com micobactina® J é mais efetivo para a obtenção de estirpes ovinas em Portugal

A seroepidemiological survey of Mycobacterium avium subsp. paratuberculosis in sheep from North of Portugal

The aim of this study was evaluate the risk factors for Mycobacterium avium subsp. paratuberculosis (Map) seroprevalence in sheep in the North of Portugal. The effects on seroprevalence of several variables such as individual characteristics, management practices, farm characteristics, animal health, and available veterinary services were evaluated. This information was then used in a multivariable logistic regression model in order to identify risk factors for Map seropositivity. Univariable analysis was used to screen the variables used in the logistic regression model. Variables that showed p values of <0.15 were retained for the multivariable analysis. Fifteen variables were associated with paratuberculosis in univariable analysis. The multivariable logistic regression model identified a number of variables as risk factors for seropositivity like sheep pure local and/or a cross of a local breed (OR=2.02), herd size with 31-60 head (OR=2.14), culling during the Spring-Summer season (OR=1.69) and the use of an anti-parasitic treatment such as Ivermectin as the only anti-parasitic medication (OR=5.60). Potential risk factors identified in this study support current recommendations for the control of paratuberculosis