Introduction: Dengue-, Zika-and Chikungunya infections are among the most frequently
imported tropical arbovirus infections. Due to their shared endemic regions, vectors
and similar clinical symptoms, differential diagnosis is based on serological and
molecular analysis. Objective: The aim of our study was to identify the imported arbovirus
infections of travellers between 2016 and 2020. Furthermore, to improve the diagnostic
sensitivity, anticoagulated whole blood and urine samples were involved in molecular
diagnosis. Method: Virus-specific antibody kinetics was tested in paired sera of patients
by ELISA method. In case of reactive results, further serological analysis was performed
using immunofluorescence assays and/or ELISA tests to exclude serological cross-reactions
caused by other members of the flavi-and alphaviruses. Detection of viral RNA was
attempted from serum, anticoagulated whole blood and urine specimens using reverse
transcription and real-time polymerase chain reaction. Results: Out of the tested
1037 travellers, reactive serological and/or molecular results were obtained in 133
cases. Anticoagulated whole blood proved to be the most suitable specimen for viral
RNA detection of the three viruses. Discussion: Parallel testing of Dengue-, Zika-and
Chikungunya infections is recommended, as symptom-based differential diagnosis is
challenging. Due to the characteristic serological cross-reactivity of flavi-and alphaviruses,
microbiological diagnosis relies on both serological and molecular tests. Conclusion:
Involving anticoagulated whole blood and urine samples into molecular analysis and
early sample collection improve the sensitivity of microbiological diagnostics. Identification
of imported tropical arbovirus infections is of high importance as the presence of
vector mosquitos in Europe raises the possibility of autochthon transmission.
