Borde et al.
Decoding the geography of natural TBEV microfoci in Germany: A geostatistical approach based on land-use patterns and climatological conditions.
Int J Environ Res Public Health. 2022;19(18):11830. doi:10.3390/ijerph191811830

There have been several published models to elucidate factors that contribute to the infection rate of humans in a given TBE endemic area. Among these prediction models are factors like weather conditions, population dynamics of rodents, beech mast, land use, etc.

TBE virus is not homogenously distributed throughout questing ticks across all locations but is detected in defined areas of about 1 ha, which are commonly termed microfocus. The goal of a recently published project was to analyze potential uniform geographic patterns of identified microfoci in Germany, and a total of 56 confirmed microfoci were included in this study, in which characteristics of environmental variables were compared with control comparators.

In TBE microfoci, land-use types like vineyards, coniferous and mixed forest were overrepresented, while types like discontinuous urban fabric, non-irrigated arable land, pastures and broad-leaved forests were overrepresented at the control sampling points. Among climatological variables, multi-annual sunshine duration, multi-annual minimum temperature, multi-annual hot days and multi-annual actual evapotranspiration may control the presence or absence of microfoci. The highest predicted probability for the presence of TBE virus was calculated for the federal states of Bavaria and Baden-Wuerttemberg.

The current model may enable public health care authorities to anticipate where new TBE microfoci and potential consecutive infections will appear, and the current risk classification of the Robert Koch Institut (Berlin) based on notification data may be complemented with biological factors and findings presented here.

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