Tick abundance, pathogen prevalence, and disease incidence in two contrasting regions at the northern distribution range of Europe

Table 1 A summary of patterns and hypotheses to explain the regional variation of tick-borne disease cases in eastern and western Norway. All numbers are means for the entire data period (see other tables for detail). Densities are relative to total land area (in km² for 2012)

Patterns/mechanisms	Eastern Norway	Pattern/conclusion	Western Norway	Z or t	P
Cases (sum 2006–2015)
Lyme disease	96	<	133	2.09	0.041
Anaplasmosis sheep	0	<	194
Anaplasmosis cattle	0	<	134
Babesiosis cattle	3	<	214	2.97	0.004
Population sizes
Humans	648,071	>	107,542	-4.50	< 0.001
Sheep (registered ewes)	4324	<	24,728	6.05	< 0.001
Cattle (outfield grazing)	4963	<	22,697	6.91	< 0.001
Population densities (mean)
Humans	74.76	>	5.73	4.31	< 0.001
Sheep	0.49	<	1.32	-3.30	0.002
Cattle	0.56	<	1.21	-2.88	0.006
Incidence (mean)
Lyme disease (per 100,000)	1.49	<	12.41	6.12	< 0.001
Anaplasmosis sheep (per 10,000)	0	<	7.90
Anaplasmosis cattle (per 10,000)	0	<	5.83
Babesiosis cattle (per 10,000)	0.72	<	9.32	4.38	< 0.001
Nymphal tick abundance (per 20 m²)	1.36	<	5.78	2.08	0.038
Pathogen prevalence in nymphs
B. burgdorferi (s.l.)	11.4%	≥	11.3%	-1.364	0.172
A. phagocytophilum	1.0%	<	4.5%	-5.346	< 0.001