Seroprevalence of Lyme borreliosis in Finland 50 years ago

Abstract

Editor: S.J. Cutler Keywords:Europe Lyme borreliosis Seroprevalence historical risk factors a b s t r a c t Objectives: Lyme borreliosis (LB) is a tick-borne infection common in Europe. In Finland, the LB seroprevalence in the healthy population was 3.9% in 2011. While the present-day seroprevalence of LB is well characterized in several European areas, there are no studies on the seroprevalence of LB before the description of the infection in the late 1970s. Methods: We used a subset of historical serum samples (n ¼ 994) collected during the Finnish Mobile Clinic Health Survey, a nationwide cross-sectional health survey of the 1960s and 1970s. All samples were screened with Borrelia burgdorferi whole-cell sonicate IgG ELISA. The seropositivity of the samples was further confirmed by the C6 peptide ELISA and recomBead IgG 2.0 bead immunoassay. The association of LB seropositivity with risk factors and with self-reported diseases and symptoms relating to disseminated LB were analysed by logistic regression. Results: B. burgdorferi IgGs were detected in 199 of 994 analysed samples; hence, the overall seroprevalence was 20.0% (95% confidence interval: 17.6e22.6). The highest seroprevalence was observed in persons aged 50 years (165/696), in those currently not working (92/383), and in the regions of South and Central Finland (91/226 and 27/88, respectively). Further, perception of feeling unhealthy (129/197 versus 412/794) was higher among LB-seropositive individuals compared to LB-seronegative participants. Conclusion: LB seroprevalence was considerably higher in Finland in the late 1960s and early 1970s than in 2011. This result questions the perception of an unprecedentedly high LB seroprevalence in presentday Europe.

Tick populations from endemic and non-endemic areas in Germany show differential susceptibility to TBEV

“…Nevertheless, our data provide the first evidence that there might be co-infection interference between Borrelia and TBEV. These results would fit well with the observed decrease of Borrelia infection rates in Finland 54 , whereas TBEV infection rates show a dramatic increase of TBE in Finland 55 . Additionally, other factors including other microbiota and the virome of ticks could contribute to differences in susceptibility of TBEV between different parts of Germany.…”

Widespread circulation of pertussis in Finland during 1968–1972 when the whole cell vaccine was in use

“…The sera have been stored at -20°C for 50 years, and the frequent thawing and freezing have been avoided. Recently, the samples were successfully tested for IgG antibodies against Borrelia burgdorferi [6]. Additionally, anti-PT antibody titres up to IU/mL were detected in this study, which further supports the assumption that the serum samples were not affected by the storage.…”

Re: ‘Seroprevalence of Lyme borreliosis in Finland 50 years ago’ by Cuellar et al.

“…Notably, the relationship between IgG antibodies for B. burgdorferi and storage conditions needs further investigation [5]. On the one hand, if the seropositive samples for B. burgdorferi from this study are still being stored, we strongly believe that they should be tested by the same methods in the future [1]. On the other hand, the LB seroprevalence among the general population was investigated in Finland in 2011 [3].…”

“…We read with interest 'Seroprevalence of Lyme borreliosis in Finland 50 years ago' [1]. The authors studied the Lyme borreliosis (LB) seroprevalence in Finland in the 1960s and 1970s through evaluation of immunoglobulin G (IgG) against Borrelia burgdorferi in historical serum samples.…”