Lyme Borreliosis in Finland, 1995–2014

Abstract

We investigated the epidemiology of Lyme borreliosis (LB) in Finland for the period 1995–2014 by using data from 3 different healthcare registers. We reviewed data on disseminated LB cases from the National Infectious Diseases Register (21,051 cases) and the National Hospital Discharge Register (10,402 cases) and data on primary LB (erythema migrans) cases from the Register for Primary Health Care Visits (11,793 cases). Incidence of microbiologically confirmed disseminated LB cases increased from 7/100,000 population in 1995 to 31/100,000 in 2014. Incidence of primary LB cases increased from 44/100,000 in 2011 to 61/100,000 in 2014. Overall, cases occurred predominantly in women, and we observed a bimodal age distribution in all 3 registers. Our results clearly demonstrate that the geographic distribution of LB has expanded in Finland and underscore the importance of LB as an increasing public health concern in Finland and in northern Europe in general.

High tick abundance and diversity of tick-borne pathogens in a Finnish city

“…Of these diseases, borreliosis (= Lyme disease) and tick-borne encephalitis (TBE) are considered the most serious for public health. Both the abundance of ticks and the numbers of diagnosed tick-borne diseases have increased in many European countries in recent decades (e.g., Jaenson et al 2012;Sajanti et al 2017). Not all of the reasons for these increases have been explored, but a substantial role for the changing climate has commonly been emphasized (e.g., Jaenson et al 2012;Medlock et al 2013; Estrada-Peña and de la Fuente 2014; Jore et al 2014;Medlock and Leach 2015;Alkishe et al 2017).…”

Large erythema migrans lesion in Lyme disease

“…The prevalence of Borrelia infection in Ixodes persulcatus ticks was 34.5% in Hokkaido, Japan, similar to that in Finland . Although the incidence of Lyme disease is more than 50 cases per 100 000 population per year in Finland, only five cases were reported in 2018 in Hokkaido (0.1 cases per 100 000 population per year) …”

“…2 Although the incidence of Lyme disease is more than 50 cases per 100 000 population per year in Finland, only five cases were reported in 2018 in Hokkaido (0.1 cases per 100 000 population per year). 3,4 Early diagnosis is important to prevent complications. The Infectious Diseases Society of America guidelines suggest that the clinical manifestation of erythema migrans is sufficient to make a diagnosis of Lyme disease in the absence of laboratory confirmation.…”

­­Lyme borreliosis in Finland: A register-based linkage study

“…In our previous study, we evaluated the total annual number of LB cases in Finland (6440 cases in 2014) by summing clinically diagnosed and microbiologically confirmed LB cases together (17). According to the international and national guidelines, the first line treatment for EM is oral amoxicillin (3,23).…”

“…The aim was both to characterize the LB cases that were diagnosed in inpatient health care units but that were not microbiologically confirmed, and to evaluate the quality of Hilmo concerning LB notifications. We focused on two main hospital districts (HD) in Finland, Helsinki and Uusimaa HD (population 1.6 million) and Varsinais-Suomi HD (population 480,000), which locate in the highly endemic LB area in south coast of Finland (17). Thus, a subgroup of 396 (57.8%) microbiologically unconfirmed hospital cases (i.e.…”