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Background: Usutu virus (USUV) and West Nile virus (WNV) are zoonotic arthropod-borne orthoflaviviruses. The enzootic transmission cycles of both include Culex mosquitoes as vectors and birds as amplifying hosts. For more than 10 years, these viruses have been monitored in birds in Germany by a multidisciplinary network. While USUV is present nationwide, WNV used to be restricted to the central-east., Methods: In 2021 and 2022, over 2300 live bird blood samples and organs from over 3000 deceased birds were subjected to molecular and serological analysis regarding the presence of WNV and USUV. The samples were collected at sites all over Germany., Results: Circulation of both viruses increased in 2022. For USUV, the nationwide presence of lineages Africa 3 and Europe 3 reported in previous years was confirmed. Lineage Europe 2, formerly restricted to the German east, was able to expand westward. Nonetheless, USUV neutralizing antibody (nAb) detection rates remained low (< 9%). Years 2021 and 2022 were characterized by stable enzootic circulation of WNV lineage 2, dominated by one previously identified subcluster (95% of generated sequences). In 2022, >20% of birds in the endemic region in eastern Germany carried nAb against WNV. Serological data also indicate expanding WNV circulation west and south of the known hotspots in Germany., Conclusions: USUV circulates enzootically nationwide. Emergence of WNV at several new locations in Germany with a potential increase in human infections may be imminent. In this context, wild bird monitoring serves as a capable early warning system in a One Health setting.

We observe the fluorescence of pristine diamondoids in the gas phase, excited using narrow band ultraviolet laser light. The emission spectra show well-defined features, which can be attributed to transitions from the excited electronic state into different vibrational modes of the electronic ground state. We assign the normal modes responsible for the vibrational bands, and determine the geometry of the excited states. Calculations indicate that for large diamondoids, the spectral bands do not result from progressions of single modes, but rather from combination bands composed of a large number of Δv = 1 transitions. The vibrational modes determining the spectral envelope can mainly be assigned to wagging and twisting modes of the surface atoms. We conclude that our theoretical approach accurately describes the photophysics in diamondoids and possibly other hydrocarbons in general.