Table 3.

Estimates of National Incidence of Lyme Borreliosis (Cases per 100,000 Population per Year) in Northern Europe (Nordic Region) from the Literature Published from 2005 to 2020

Country	Data source	Study design	Study population	Case definition	Study period	No. of cases	Incidence (cases per 100,000 PPY)
Denmark (Dessau et al., 2015)	Danish Notification System for Infectious Diseases, Danish Microbiology Database, Danish civil registration system	Prospective cohort	National population	LNB	2010 − 2012	533	3.2
Denmark (Tetens et al., 2020)	Danish national registries	Retrospective cohort	National population	LNB—positive for intrathecal antibodies	1996 − 1999	480	2.2
					2000 − 2003	579	2.7
					2004 − 2007	714	3.3
					2008 − 2011	616	2.8
					2012 − 2015	402	1.8
					1996 − 2015	2791	2.6
Finland (Sajanti et al., 2017)	National infectious disease register, national hospital discharge register, register for primary health care visits	Retrospective cohort	National population	Microbiologically confirmed	1995	345	7
					2014	1679	31
				Clinically diagnosed	2011–2014	11,793
					2011		44
					2014		61
				Estimated annual	2011	5011	93
				Estimated annual	2014	6440	118
Sweden (Dahl et al., 2019)	National laboratory reporting	Retrospective cohort	National population	LNB—positive CSF fluid-serum antibody index	2010	578	6.1
					2011	689	7.3
					2012	559	5.8
					2013	561	5.9
					2014	604	6.3

Incidence estimates and 95% CIs have been rounded to the first decimal to the right for consistent level of precision.

CI, confidence interval; CSF, cerebrospinal fluid.