Prevalence and herd-level risk factors of bovine tuberculosis in the State of Santa Catarina

Abstract

With the aim of supporting the strategic planning of the National Program for Control and Eradication of Brucellosis and Tuberculosis, different Brazilian states have been conducting cross-sectional studies, coordinated by the Ministry of Agriculture, Livestock, and Supply and with scientific support from the University of São Paulo and the University of Brasilia. In Santa Catarina, the State Animal Health Agency (CIDASC) conducted a study on bovine tuberculosis (TB) prevalence and assessment of risk factors in 2012. The state was divided into five regions and, in each region, independent sampling was performed in two steps: (i) cattle herds with reproductive activity were randomly selected; and (ii) in each herd, a sample of females aged 24 months or older underwent the intradermal comparative tuberculin test. A questionnaire was used to collect data on production characteristics and management practices that could be associated with the tuberculosis infection. Herd prevalence of bovine TB was 0.50% (95% confidence interval [CI]: 0.074-0.93%) while the prevalence of TB in adult females was 0.06% (95% CI: 0-0.12%). No significant difference in the prevalence of infected herds and of positive females was observed among the five regions. The logistic regression model revealed that herds with 19 or more females showed an odds ratio (OR) of 7.68 (95% CI: 1.22-48.39) compared to smaller herds, while dairy herds presented an OR of 10.43 (95% CI: 2.00-54.25) relative to beef or dual-purpose herds. The results suggest that dairy herds, in which animals are kept in partial or total confinement, and larger herds, which tend to acquire animals more often, are at a higher risk of bovine TB. Given the low prevalence and the type of higher-risk properties, a bovine TB surveillance system should be targeted at the state's dairy basins, particularly the western region that accounts for the major industries and more intensive dairy farms. (TB). O Estado foi dividido em cinco regiões e, em cada uma delas, foi realizada uma amostragem independente em duas etapas: (i) propriedades com atividade reprodutiva foram selecionadas aleatoriamente; (ii) em cada propriedade, uma amostra de fêmeas com idade igual ou superior a 24 meses foi submetida ao teste tuberculínico intradérmico comparativo. Um questionário foi utilizado para recolher dados sobre as características de produção e práticas de gestão que poderiam estar associados com a infecção tuberculosa. A prevalência de focos de tuberculose bovina foi de 0,50% (95% intervalo de confiança [CI]: 0,074-0,93%), enquanto a prevalência de TB em animais foi de 0,06% (IC 95%: 0-0,12%). Não foi observada diferença significativa na prevalência de focos ou animais entre as cinco regiões. O modelo de regressão logística revelou que rebanhos com 19 ou mais vacas apresentaram um odds ratio (OR) de 7,68 (IC 95%: 1,22-48,39) em comparação com rebanhos menores, enquanto rebanhos leiteiros apresentaram um OR de CI 10,43 (95%: 2.00-54,25) em relação aos rebanhos de corte ou de duplo propósito. ...

Epidemiological status of bovine tuberculosis in the Federal District of Brazil

“…Studies based on bovine tuberculosis, conducted in 12 Federative Units, which contain 75% of the Brazilian herd, showed herd prevalence estimates between 0.5% and 9.0% in Santa Catarina and São Paulo, respectively (BAHIENSE et al, 2016;BARBIERI et al, 2016;DIAS et al, 2016;GALVIS et al, 2016;GUEDES et al, 2016;LIMA et al, 2016;NÉSPOLI et al, 2016;QUEIROZ et al, 2016;ROCHA et al, 2016;SILVA et al, 2016;VELOSO et al, 2016;VENDRAME et al, 2016). The same authors observed that the risk of bovine tuberculosis increased in larger dairy cattle herds on farms that use some degree of automation in the dairy production process.…”

Epidemiological situation of bovine tuberculosis in the State of Pernambuco, Brazil

“…The higher probability of infection in herds from properties with more animals was also verified in the Republic of Ireland (GRIFFIN et al, 1996;CLEGG et al, 2012), United Kingdom (REILLY; COURTENAY, 2007;RAMÍREZ-VILLAESCUSA et al, 2010;BESSELL et al, 2012), New Zealand (PORPHYRE et al, 2008), and Brazil (BAHIENSE et al, 2016DIAS et al, 2016;GALVIS et al, 2016;SILVA et al, 2016;BAUMGARTEN et al, 2016). Larger herds present greater replacement rates, increasing the risk of inclusion of infected animals.…”

“…Dairy herds are more vulnerable to tuberculosis because dairy production involves animal confinement during milking, which increases the risk of transmission (BARLOW et al, 1997), considering that confinement increases the population density and consequently the probability of infectious contacts (HUMBLET et al, 2010;ALVAREZ et al, 2012). Dairy herds also presented greater risk for tuberculosis in New Zealand (PORPHYRE et al, 2008), United Kingdom (RAMÍREZ-VILLAESCUSA et al, 2010;KAROLEMEAS et al, 2011), andBrazil (BAHIENSE et al, 2016;BARBIERI et al, 2016;DIAS et al, 2016;GALVIS et al, 2016;ROCHA et al, 2016;SILVA et al, 2016;BAUMGARTEN et al, 2016). Furthermore, dairy cattle tend to be older than beef cattle and consequently, have a greater probability of exposure to the infectious agent (HUMBLET et al, 2009).…”

“…The prevalence of infected herds in these units varied between 0.36%, in the Federal District (Brasília), and 9.0%, in São Paulo (BAHIENSE et al, 2016;BARBIERI et al, 2016;DIAS et al, 2016;GALVIS et al, 2016;GUEDES et al, 2016;NÉSPOLI et al, 2016;QUEIROZ et al, 2016;RIBEIRO et al, 2016;ROCHA et al, 2016;SILVA et al, 2016;BAUMGARTEN et al, 2016;VENDRAME et al, 2016).…”

Decline in Mycobacterium bovis and Brucella abortus populations during the maturation of experimentally contaminated parmesan-type cheese

“…The extensive and systematic employment of milk pasteurization has significantly reduced the incidence of these diseases in the human population (SINHA, 1994). However, in countries such as Brazil, where these diseases are still currently widespread in herds (BRASIL, 2006a) and the consumption of dairy products prepared with raw milk persists (SOUSA, 2005; ROCHA et al, 2014), it is reasonable to accept the occurrence of human cases by this route of transmission, despite the lack of Brazilian epidemiological data corroborating this hypothesis.A recent study carried out in 13 Brazilian states, which hold 75% of the country cattle population, showed the prevalence of tuberculosis infected herds ranging from 0.36% in the Federal District to 9.0% in São Paulo (BAHIENSE et al, 2016;BARBIERI et al, 2016;DIAS et al, 2016b;GALVIS et al, 2016;GUEDES et al, 2016;LIMA et al, 2016;NÉSPOLI et al, 2016;QUEIROZ et al, 2016;RIBEIRO et al, 2016;ROCHA et al, 2016;SILVA et al, 2016a;VELOSO et al, 2016;VENDRAME et al, 2016). In relation to bovine brucellosis, 18 Brazilian states were recently studied, comprising 85% of the country cattle population, and the prevalence ranged from 0.91% in Santa Catarina to 30.6% in Mato Grosso do Sul ALVES et al, 2009;ANZAI et al, 2016;BARDDAL et al, 2016;BAUMGARTEN et al, 2016; BORBA et al, 2013; CLEMENTINO et al., 2016;DIAS et al, 2009;DIAS et al, 2016a;INLAMEA et al, 2016;KLEIN-GUNNEWIEK et al, 2009;LEAL FILHO et al, 2016;OGATA et al, 2009;OLIVEIRA et al, 2016;ROCHA et al, 2009; SILVA et al, 2016b;SILVA et al, 2009).…”