Detecting silent threats: Jingmenvirus surveillance in ticks

Ticks are among the main vectors of infectious agents for humans and animals and, in addition to bacteria and protozoa, they also harbor and transmit several viruses of growing public health concern. In recent years, the use of new molecular techniques has led to the discovery of various emerging viruses, some of which associated with clinical syndromes in humans. Among the new viruses discovered, Alongshan virus (ALSV) and Jingmen tick virus (JMTV), belonging to the Jingmenvirus group and currently classified within the Flaviviridae family, have been reported in Kosovo and China in association with febrile syndromes, although their actual clinical involvement has not yet been clarified. The aim of this thesis was to investigate the circulation of ALSV and JMTV in Italy, where epidemiological data are currently lacking, despite their presence already being documented in several European countries. To this end, ticks collected in different areas of Northern, Central, and Southern Italy were analyzed using a one-step multiplex real-time RT-PCR assay. For ALSV-positive samples, subsequent nested-PCR reactions were performed, followed by sequencing. This was done with the aim of obtaining and characterizing the complete genomic sequences of the four viral segments. The analyses confirmed for the first time the presence of ALSV and JMTV in Italy, contributing to a more comprehensive picture of the spread of these viruses in Europe and providing a basis for further epidemiological research. In addition, the genomic data obtained for ALSV enabled preliminary phylogenetic studies. These studies were useful for comparing the strains circulating in Italy with those described in other parts of the world, providing information on the processes of adaptation and evolutionary dynamics of ALSV. Concurrently, sequences encoding structural proteins of ALSV were cloned and expressed in cell lines. These were used to test human sera obtained from individuals exposed to tick bites to detect the presence of anti-ALSV antibodies. The ultimate goal of this process was to evaluate the circulation of the virus in human populations.