Risk factors of bovine tuberculosis in cattle in rural livestock production systems of Ethiopia

Abstract

This study shows a representative stratified cluster sample survey of the prevalence of comparative intradermal tuberculin test in cattle from four regions in Ethiopia. Using a cut-off for positivity of 2 mm, it assesses possible risk factors for tuberculin-positive reaction in cattle. Seventy-three villages in 24 kebeles (administrative units) were randomly selected, from which 2216 cattle from 780 owners were tested. In addition, 450 of these cattle owners were interviewed for risk factor assessment. Ninety-nine percent of the tested cattle in this rural livestock production system were traditional zebus. The individual overall prevalence of cattle bovine tuberculosis (BTB)e was 3%, with the highest found in Meskan Mareko, in Central Ethiopia (7.9%) and the lowest in Woldia, in the North East edge of the Rift Valley (1.2%). Generalised Linear Mixed Models (GLMM) with random effect on kebeles was used to analyse risk factors of cattle reactors and human tuberculosis (TB) infection. Purchase of cattle and presence of other livestock in the herd were statistically significant, with OR: 1.7, p-values of 0.03 and OR: 2, p = 0.05, respectively. Family members diagnosed with TB or showing clinical signs of extra-pulmonary TB (EPTB) were reported in 86 households (19%). None of the assessed potential risk factors of disease transmission between cattle and human (food consumption, livestock husbandry and presence of BTB-positive cattle) were statistically significant.

Epidemiological status of bovine tuberculosis in the State of Rio Grande do Sul, Brazil

“…Larger flocks have a higher replacement rate, thus increasing the risk of introduction of infected animals. The purchase of animals, in particular from risk farms, has paramount importance in the transmission of bovine tuberculosis (BESSELL et al, 2012;OLOYA et al, 2007;RAMÍREZ-VILLAESCUSA et al, 2010;REILLY;COURTENAY, 2007;SKUCE et al, 2012;TSCHOPP et al, 2009). Thus, it is plausible to assume that this variable indicates that the purchase of animals, naturally without prior testing, implies a magnification of the risk of introduction of bovine tuberculosis in a farm.…”

Analysis of 15 years of the National Program for the Control and Eradication of Animal Brucellosis and Tuberculosis, Brazil

“…The purchase of animals, in particular from high-risk properties, plays an essential role in the transmission of bovine tuberculosis (REILLY;COURTENAY, 2007;OLOYA et al, 2007;TSCHOPP et al, 2009;RAMÍREZ-VILLAESCUSA et al, 2010;SKUCE et al, 2012;BESSELL et al, 2012). Hence, it is plausible to assume that this variable indicates that the purchase of animals without prior testing increases the risk of introducing bovine tuberculosis to a farm.…”

Prevalence of bovine tuberculosis in cattle in the highlands of Cameroon based on the detection of lesions in slaughtered cattle and tuberculin skin tests of live cattle

“…In this work, the spread of the pathogen in the extensive and semi-extensive systems could have resulted from the closer contact experienced during periods of drought at shared grazing, watering and salt leak points, "cattle markets", during veterinary interventions (vaccination campaigns), and other ventures that involved the gathering together of different herds of animals. While the daily gathering of different herds at a site may not necessarily lead to the spread of bovine TB (Tschopp et al 2009), a small number of infective agents can still cause disease in susceptible cattle (Francis 1971;Goodchild and Clifton-Hadley 2001;Cassidy 2006). The presence of a single or small number of animals shedding the disease agent (M. bovis), in their faeces, milk, discharging lesions, cough and aerosol sprays, saliva and urine would therefore be important sources for contamination and spread (O'Reilly and Daborn 1995;Cook et al 1996;Asseged et al 2004;Ayele et al 2004).…”