BackgroundLyme borreliosis (LB), caused by Borrelia burgdorferi (Bb), is the most common tick-borne infection in Germany. Antibodies against Bb are prevalent in the general population but information on temporal changes of prevalence and estimates of seroconversion (seroincidence) and seroreversion are lacking, especially for children and adolescents. AimWe aimed at assessing antibodies against Bb and factors associated with seropositivity in children and adolescents in Germany. MethodsWe estimated seroprevalence via two consecutive cross-sectional surveys (2003–2006 and 2014–2017). Based on a longitudinal survey component, we estimated annual seroconversion/seroreversion rates. ResultsSeroprevalence was 4.4% (95% confidence interval (CI): 3.9–4.9%) from 2003 to 2006 and 4.1% (95% CI: 3.2–5.1%) from 2014 to 2017. Seroprevalence increased with age, was higher in male children, the south-eastern regions of Germany and among those with a high socioeconomic status. The annual seroconversion rate was 0.3% and the annual seroreversion rate 3.9%. Males were more likely to seroconvert compared with females. Low antibody levels were the main predictor of seroreversion. ConclusionWe did not detect a change in seroprevalence in children and adolescents in Germany over a period of 11 years. Potential long-term changes, for example due to climatic changes, need to be assessed in consecutive serosurveys. Seroconversion was more likely among children and adolescents than among adults, representing a target group for preventive measures. Seroreversion rates are over twice as high in children and adolescents compared with previous studies among adults. Thus, seroprevalence estimates and seroconversion rates in children are likely underestimated. …

BackgroundLyme borreliosis (LB) is the most common tick-borne disease (TBD) in France. Forestry workers are at high risk of TBD because of frequent exposure to tick bites. AimWe aimed to estimate the seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus (TBEV) antibodies among forestry workers in northern France. We compared seroprevalence by geographical area and assessed factors associated with seropositivity. MethodsBetween 2019 and 2020, we conducted a randomised cross-sectional seroprevalence survey. Borrelia burgdorferi sl seropositivity was defined as positive ELISA and positive or equivocal result in western blot. Seropositivity for TBEV was defined as positive result from two ELISA tests, confirmed by serum neutralisation. We calculated weighted seroprevalence and adjusted prevalence ratios to determine association between potential risk factors and seropositivity. ResultsA total of 1,778 forestry workers participated. Seroprevalence for B. burgdorferi sl was 15.5% (95% confidence interval (CI): 13.9–17.3), 3.5 times higher in the eastern regions than in the western and increased with seniority and with weekly time in a forest environment. Seroprevalence was 2.5 times higher in forestry workers reporting a tick bite during past years and reporting usually not removing ticks rapidly. Seroprevalence for TBEV was 0.14% (95% CI: 0.05–0.42). ConclusionWe assessed for the first time seroprevalence of B. burgdorferi sl and TBEV antibodies among forestry workers in northern France. These results will be used, together with data on LB and tick-borne encephalitis (TBE) incidence and on exposure to tick-bites, to target prevention programmes. …

Lyme Disease -- LatviaMore than 20% of the ticks analyzed in all Latvian laboratories have been tested positive for Lyme _Borrelia_ [bacteria] this year [2023]. _Borrelia_ can cause Lyme disease against which there are no vaccines. The other dangerous tick-borne illness -- encephalitis -- has only been found in a few ticks, Latvian Television reported on 26 May 2023.At the Latvian Infectology Center, encephalitis has not been detected at all this year [2023], but 26% of the tested ticks have shown _Borrelia_.