“…Using the procedure of (Dohoo et al, 2003), a sample size of 76 herds was calculated from the study areas by assuming that brucellosis existed at 17% (Muma et al, 2006). The sample sizes of individual animals per farm were estimated using Herdacc® (Jordan, 1995), by assuming that the sensitivity (Se) and specificity (Sp) for RBT were 90% and 75% (Muma et al, 2007c), and the c-ELISA, Se and Sp 98% and 99%, respectively (Nielsen et al, 1996). Based on the above assumptions, herd sensitivity (Hse) and herd specificity (Hsp) were estimated at 98.0% and 100%, respectively, when a 10% sampling fraction was used and farms classified as positive when at least a single brucellosis positive animal was detected.…”