Ticks and Tick-Borne Pathogens: Occurrence and Host Associations over Four Years of Wildlife Surveillance in the Liguria Region (Northwest Italy).

Tick-borne diseases (TBDs) are a considerable public health problem worldwide. The occurrence of Anaplasma spp., Borrelia burgdorferi s.l., Coxiella burnetii, Rickettsia spp., and tick-borne encephalitis virus (TBEv) was investigated via PCR and sequencing in 683 ticks collected from 105 roe deer, 61 wild boars, 49 fallow deer, and 2 chamois, in the Liguria region, northwest Italy, between 2019 and 2022. The ticks were morphologically identified. Four different tick species were found: Ixodes ricinus (66.8% of the collected ticks), Dermacentor marginatus (15.8%), Rhipicephalus sanguineus s.s. (15.7%), and Haemaphysalis punctata (0.9%). Six ticks (0.9%) were only identified as Rhipicephalus spp. Of the 222 pools analyzed, 27.9% were positive. Most pools (n = 58, 26.1% of pools analyzed) were positive for Rickettsia spp., and several species were found: Rickettsia slovaca was the dominant species (15.3%), followed by R. monacensis (8.1%), while R. helvetica (1.8%), R. massiliae (0.5%), and R. raoultii (0.5%) were found only sporadically. Anaplasma phagocytophilum was identified in three pools and B. burgdorferi s.l. in one pool. All samples were negative for C. burnetii and TBEv. Significant associations were found between I. ricinus and roe deer, D. marginatus and wild boar, and between R. monacensis and I. ricinus. The prevalence of Rickettsia spp. differed significantly between tick and host species. This updated picture of tick species and TBPs in wild ungulates in Liguria, where the population of these animals is increasing, shows a widespread presence of potentially zoonotic Rickettsia spp. Continuous monitoring and public information on preventive measures are needed.

First record of Aedes japonicus in Liguria region, Northwest of Italy.

Aedes japonicus is an invasive Asian mosquito species, and to date it is widespread in many European countries. In Italy, it was first recorded in 2015 at the Austrian border and it then spread throughout the Northeast of the country. In 2019, it was also identified in Piedmont region, near the Swiss border. In the framework of the Italian program for prevention, surveillance, and response to Arboviruses, from June to November 2021, biweekly entomological surveillance was performed in the Liguria region (Northwest Italy). The collected mosquitoes were morphologically and genetically identified and molecularly analysed for the detection of West Nile and Usutu viruses. Six female mosquitoes, trapped on the 6th of July 2021 using a gravid trap in Albenga (Savona province), were morphologically identified as Ae. japonicus and the identification was genetically confirmed. The pool tested was negative for the presence of West Nile and Usutu viruses. The detection of Ae. japonicus was performed in a coastal area characterized by the presence of many floriculture activities. Considering the distance from the established Ae. japonicus mosquito populations in Italy and other European countries, this could represent an independent introduction in this country.

Hard Ticks (Ixodidae) from Wildlife in Liguria, Northwest Italy: Tick Species Diversity and Tick-Host Associations.

Hard ticks' geographical distribution and abundance are influenced by wildlife population. This work presents the results of the identification of ticks retrieved from wild animals in the framework of a Regional Plan of Monitoring and Surveillance of Wildlife health. The frequency of distribution of ticks in different hosts and their geographical patterns were also investigated. Ticks were collected from game animals (Sus scrofa, Capreolus capreolus, Dama dama, and Rupicapra rupicapra) during two hunting seasons (2018-2019 and 2019-2020) in the four provinces of the Liguria region in northwest Italy. In the same period, ticks were also collected from carcasses of Vulpes vulpes, Canis lupus, Meles meles, and Asio otus received for necropsy. Tick species were identified according to taxonomic keys. A total of 819 ticks, removed from 259 animals, were found and identified. Overall, Ixodes ricinus was the dominant species (62.6%), followed by Dermacentor marginatus (24.5%), Rhipicephalus sanguineus s.l. (12.5%), Haemaphysalis punctata (0.2%), and Ixodes hexagonus (0.1%). I. ricinus was also the prevalent species in roe deer and in fallow deer and the only species collected from the three wolf carcasses examined. In contrast, D. marginatus was the dominant species in S. scrofa. This last tick species was also more frequent in one province (Imperia), whereas Ixodes spp. were more common in another one (Savona). Wild animals proved to be useful for characterizing and monitoring tick population.

First report of the invasive mosquito Aedes koreicus (Diptera: Culicidae) and of its establishment in Liguria, northwest Italy.

BACKGROUND: Invasive mosquito species (IMS) of the genus Aedes are a cause of increasing concern in Europe owing to their ability to vector important human viral diseases. Entomological surveillance to early detect alien mosquito and flavivirus circulation in Liguria, northwest Italy, has been carried out since 2011. RESULTS: The invasive species Aedes koreicus was first detected in Genoa in September 2015, when a male specimen was caught near the international airport; species identity was confirmed by genetic analysis. Over the next three years, 86 more adult specimens were trapped at sites throughout the city, accounting for 0.50% of all mosquitoes and 1.04% of Aedes sp. mosquitoes trapped in Genova in the four-year period 2015-2018. So far, no other monitored sites in Liguria have revealed the presence of this species. Ovitraps at two sites became positive for the species in July-August 2017. All female Ae. koreicus pools analysed were negative in biomolecular assays for Flavivirus. CONCLUSIONS: Our findings of Ae. koreicus in Genoa constitute, to the best of our knowledge, the first report of the species in northwest Italy and in a Mediterranean port city. The species appears to be established; trapping and climatic data support survival of Ae. koreicus in the area through three consecutive winters. Monitoring of adult mosquitoes detected the species two years before its discovery with ovitraps; trapping for adult specimens appears to be a more effective tool for the early detection of IMS. The airport (located near the commercial port area) and the flower market are the most probable sites of introduction; however, the exact time and place of arrival of this IMS in Liguria remain unknown. Based on morphological and genetic data, a common origin for most of the Ae. koreicus populations established in Europe is suspected. So far, no control measures have been adopted in Genoa and the species will probably colonize an even wider area in the next few years.

Detection of West Nile and Usutu Viruses in Italian Free Areas: Entomological Surveillance in Piemonte and Liguria Regions, 2014.

West Nile virus and Usutu virus have established in different parts of Italy over the past 10 years. Piemonte and Liguria Regions (Northwestern Italy) are known to be nonendemic areas, despite the presence of competent vectors and environmental conditions conducive to maintaining infection. This work evidences for the first time, through an entomological surveillance implemented on the basis of risk factor approach, the presence of West Nile and Usutu viruses in Piemonte and Liguria Regions (Northwestern Italy).

Cases of bed bug (Cimex lectularius) infestations in Northwest Italy.

CBed bugs (Cimex lectularius) have been a common problem for humans for at least 3,500 years and in Europe their presence was endemic until the end of World War II, when infestations began to decrease. However, since the beginning of the 21st century new cases of infestations have been reported in developed countries. Many theories have been put forward to explain this change of direction, but none has been scientifically proven. The aim of this study is to provide some reports of bed bug infestations in Northern Italy (Liguria, Piedmont and Aosta valley regions) and a brief summary about their identification, clinical significance, bioecology and control. From 2008 to date, 17 bed bug infestations were identified in Northwest Italy. Knowledge about the presence and distribution of bed bugs in Italy is scanty, prior to this work only 2 studies reported the comeback of these arthropods in the Italian territory; further investigations would be necessary to better understand the current situation.