Comparative assessment of two commonly used commercial ELISA tests for the serological diagnosis of contagious agalactia of small ruminants caused by Mycoplasma agalactiae

Table 2 Prevalence of M. agalactiae infection and diagnostic sensitivity of TA- and P48-ELISA kits in six infected flocks

Flock characteristics				Sero-prevalence (a)		Diagnostic sensitivity (b)
N°	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
N°	Flock size (number of adults)	Number of infected animals (c)	First infection evidence n years ago (d)	% (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.

ISSN: 1746-6148