Table 2

Prevalence ofM. agalactiaeinfection and diagnostic sensitivity of TA- and P48-ELISA kits in six infected flocks
Flock characteristics Sero-prevalence (a) Diagnostic sensitivity (b)
Flock size (number of adults) Number of infected animals (c) First infection evidence n years ago (d) TA-ELISA P48-ELISA TA-ELISA P48-ELISA
% (e) % (e) % (g) 95% Confidence interval (f) % (g) 95% Confidence interval (f)
1 272 73 1 76 (206) 24 (64) 96 (70) [88–99] 34 (25) [24–46]
2 460 217 1 68 (312) 26 (119) 89 (193) [84–93] 38 (82) [31–45]
3 250 55 2 78 (194) 24 (59) 100 (55) [94–100] 62 (34) [48–75]
4 418 93 2 35 (147) 28 (119) 52 (48) [41–62] 54 (50) [43–64]
5 473 59 3 49 (230) 40 (188) 75 (44) [62–85] 71 (42) [58–82]
6 292 112 8 77 (226) 80 (234) 93 (14) [86–97] 96 (107) [90–99]
Total 2165 609 61 (1315) 36 (783) 84 (514) [81.3–87.2] 56 (340) [51.8–59.8]

(a) % of sero-positive animals in each flock.

(b) % of sero-positives in infected animals.

(c) Number of ewes that shed M. agalactiae (as determined by PCR testing of individual composite milk samples) at least once during four successive tests 5, 4, 3 and 1.5 months prior to blood sampling that took place 6 months after the beginning of lactation.

(d) Number of years between the present and first time M. agalactiae milk positivity was detected in the flock.

(e) Number of sero-positive animals in each flock.

(f) Exact binomial test distribution.

(g) Number of sero-positives in infected animals.

Poumarat et al.

Poumarat et al. BMC Veterinary Research 2012 8:109   doi:10.1186/1746-6148-8-109

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