Arbovirus screening of mosquitoes collected in 2022 in Emilia-Romagna, Italy, with the implementation of a real-time PCR for the detection of Tahyna virus.

Several Arboviruses (Arthropod-borne virus) are a concrete health risk. While some arboviruses, such as the West Nile virus (WNV) and the Usutu virus (USUV) are actively surveyed, others are neglected, including the Tahyna virus (TAHV). In this work, we tested - searching for all the three viruses - 37,995 mosquitoes collected in 95 attractive traps, baited by carbon dioxide, distributed in the lowlands of Emilia-Romagna, northern Italy, between 19 July and 12 August 2022. Among the 668 pools obtained, WNV was detected in 45 pools of Culex (Cx.) pipiens and USUV was recorded in 24 pools of the same mosquito; ten of these Cx. pipiens pools tested positive for both WNV and USUV. Interestingly, we recorded a significant circulation of both WNV lineage 1 (WNV-L1) and lineage 2 (WNV-L2): WNV-L1 strains were detected in 40 pools, WNV-L2 strains in three pools and both lineages were detected in two pools. TAHV was detected in 8 different species of mosquitoes in a total of 37 pools: Aedes (Ae.) caspius (25), Ae. albopictus (5), Ae. vexans (3), Cx. pipiens (2), Ae. cinereus (1) and Anopheles maculipennis sl (1). The significant number of Ae. caspius-pools tested positive and the estimated viral load suggest that this mosquito is the principal vector in the surveyed area. The potential involvement of other mosquito species in the TAHV cycle could usefully be the subject of further experimental investigation. The results obtained demonstrate that, with adequate sampling effort, entomological surveillance is able to detect arboviruses circulating in a given area. Further efforts must be made to better characterise the TAHV cycle in the surveyed area and to define health risk linked to this virus.

Insect Colonisation and the Decomposition Process in Aerated versus Watertight Burial Systems.

In recent years, burial systems have covered increasingly higher costs due to the pollution caused by decomposition products. These products are understood as chemicals and microorganisms in the surrounding soil and groundwater and represent a topical issue. The purpose of this research was to ascertain the extent of decomposition when pig carcasses are buried in two different burial systems ("aerated" vs. "watertight") and catalogue the arthropods associated with burials at different time-points of removal from niches (after 6, 12, 24, 36, and 60 months). Thirteen taxa were collected in aerated niches, whereas five were collected in watertight niches. The initial access or exclusion of insect colonisers affected overall functional activity. Two Diptera species, Hydrotaea capensis and Megaselia scalaris, were the most abundant, supporting the hypothesis that insects can colonise carcasses in aerated burial systems. Furthermore, some species of bacteria have been documented as facilitators of the initial decomposition process of the carcass. Most bacterial colonies develop only in aerated niches. The trial showed that the first enzymatic-bacterial and insect actions helped promote the process of cadaveric decomposition and later skeletonisation, mainly when associated with aeration modes of the tomb/mound. The results obtained provide essential information on the process of human decomposition and taphonomy in cemeteries. Moreover, these data could benefit forensic science by adding information on insect colonisation and body modification in medico-legal investigations concerning the post-mortem interval in exhumed bodies and illegal burials.

Spatiotemporal Distribution of Salmonella enterica in European Hedgehogs in Northern Italy.

Growing attention is being given to the European hedgehog (Erinaceus europaeus) because of its synanthropic behaviour and its potential role in harbouring parasites, viruses, fungi and bacteria and disseminating them to several animals and humans. Salmonella are the most frequently detected zoonotic bacteria that hedgehogs could transmit through contaminating water and food sources with faeces. This study aimed to determine the prevalence and distribution of Salmonella spp. in wild hedgehogs in the Emilia-Romagna region (northern Italy). From 2019 to 2022, 212 European hedgehogs that died naturally were tested for Salmonella spp. through culture isolation. Positive samples were subjected to serological typing. A total of 82 samples tested positive for Salmonella spp., with the overall Bayesian posterior estimated prevalence ranging from 35% (95% CI: 23-47%) to a maximum of 45% (95% CI: 31-59%) during the years considered and with an overall prevalence calculated at 39% (95% CI: 33-45%). Salmonella enterica Enteritidis and Veneziana were the most prevalent detected serovars in 65% and 17% of the positive samples, respectively. Since 2021, S. Typhimurium, S. Typhimurium Monofasica, S. Zaiman, S. Hessarek, S. Muenster, S. Isangi serovars, S. enterica subsp. Diarizonae and S. enterica subsp. Houtenae have been detected. These findings show a high prevalence of Salmonella spp. in tested hedgehogs, suggesting an important role of this animal species in the epidemiology of potentially zoonotic serovars circulating in the Emilia-Romagna region.

Sand Flies and Pathogens in the Lowlands of Emilia-Romagna (Northern Italy).

Cases of sand fly-borne diseases in the Emilia-Romagna region, such as meningitis caused by Toscana virus and human leishmaniasis, are reported annually through dedicated surveillance systems. Sand flies are abundant in the hilly part of the region, while the lowland is unsuitable habitat for sand flies, which are found in lower numbers in this environment with respect to the hilly areas. In this study, we retrieved sand flies collected during entomological surveillance of the West Nile virus (from 2018 to 2021) to assess their abundance and screen them for the presence of pathogens. Over the four-year period, we collected 3022 sand flies, more than half in 2021. The most abundant sand fly species was Phlebotomus (Ph.) perfiliewi, followed by Ph. perniciosus; while more rarely sampled species were Ph. papatasi, Ph. mascittii and Sergentomyia minuta. Sand flies were collected from the end of May to the end of September. The pattern of distribution of the species is characterized by an abundant number of Ph. perfiliewi in the eastern part of the region, which then falls to almost none in the western part of the region, while Ph. perniciosus seems more uniformly distributed throughout. We tested more than 1500 female sand flies in 54 pools to detect phleboviruses and Leishmania species using different PCR protocols. Toscana virus and Leishmania infantum, both human pathogens, were detected in 5 pools and 7 pools, respectively. We also detected Fermo virus, a phlebovirus uncharacterized in terms of relevance to public health, in 4 pools. We recorded different sand fly abundance in different seasons in Emilia-Romagna. During the season more favorable for sand flies, we also detected pathogens transmitted by these insects. This finding implies a health risk linked to sand fly-borne pathogens in the surveyed area in lowland, despite being considered a less suitable habitat for sand flies with respect to the hilly areas.