Table 4.

The effect of risk factors on reinfection lice after eradication*.

Risk factor	Number of herds (n = 28)	Result 15–18 months after the eradication		Relative risk	p-value Fisher's exact test One tailed
		Free	Lice Present
Purchase of livestock or use of common pasture	20	12	8	1.41 (0.93 – 2.13)	0.17
Identified failure in precautions for livestock	9	2	7	5.25 (1.44 – 19.11)	0.005
Identified failure in precautions for persons	28	19	9	-	-

*The analysis was based on herds which succeeded with the eradication from both the pilot group and the main group.