The potential spread of severe footrot in Norway if no elimination programme had been initiated: a simulation model

Table 1 Data used for estimating minimum, mode and maximum infection rate of severe footrot in Rogaland

	Rogaland excluding Rennesøy (minimum)		Whole of Rogaland (mode)		Rennesøy (maximum)
Number of sheep flocks	2490		2597		107
Year	Assumed infected	Predicted infected	Assumed infected	Predicted infected	Assumed infected	Predicted infected
2005	1	1	1	1	0	0
2006	ND	3	ND	3	1	1
2007	ND	9	ND	14	ND	4
2008	26	26	38	48	12	13
Regional percentage of infected flocks in 2008	1.0%		1.5%		11.2%
Estimated infection rate (β)		1.13		1.31		1.36

ND = No data.
The estimates was based on data on the total number of sheep flocks and number of flocks assumed to be infected with severe footrot in the regions, from the introduction of the disease (2005 in Rogaland and 2006 in Rennesøy) until the initiation of the elimination programme in 2009. The predicted number of infected flocks in each region was the median value, of 2000 replicates of the model based on Equations 1–3. The infection rate is calculated using a constant yearly recovery rate of 5.3% and reversion rate of 1/3 of the infection rate.

ISSN: 1297-9716