Effect of lactation therapy on Staphylococcus aureus transmission dynamics in two commercial dairy herds

BMC Veterinary Research

Table 3 Staphylococcus aureus IMI eligible for 8-day lactation therapy in treatment and control pens

Treatment Pen
	All	Subclinical treated	Cure¹following subclinical therapy	Right censor reason²				Quarter with Clinical events
				exit	dry	cull	Study end	IMI started as clinical case	Flare-up during existing IMI
Farm 1	13	13	10	0	0	1	2	1	1
Farm 2	9^*	5	4	3	1	1	0	0	0
Total	22	18	14	3	1	2	2	1	1
Control Pen
	All	Subclinical treated	Spontaneous cure ³	Right censor reason ²				Quarter with Clinical events
				exit	dry	cull	Study end	IMI started as clinical case	Flare-up during existing IMI
Farm 1	16	nt⁴	0	0	6	1	9	3	8
Farm 2	0	nt	0	0	0	0	0	0	0
Total	16	nt	0	0	6	1	9	3	8

¹ Bacteriologic cure following treatment of subclinical or clinical IMI is based on negative bacteriologic culture for the pre-treatment Pulsotype (PT) on 4 of 4 samples taken at approximately 7, 14, 21, and 28 days post-treatment.
² Right censored IMI are classified to include all IMI that are not cured prior to either exit from a study pen to another lactating group (exit), dry-off (dry), culling (cull), or at the conclusion of the study (study end).
³ Spontaneous cure of an IMI is based on 2 sequential negative monthly cultures for the prior PT.
⁴ nt = not treated, i.e. subclinical IMI that would have been eligible for therapy in control pens but were not treated.
^* 4 quarters in the treatment group were eligible for subclinical therapy but exited the study pen prior to initiation of therapy (3 exited to another pen and 1 dry-off).

ISSN: 1746-6148