Mosquitoes of the Maculipennis complex in Northern Italy.

The correct identification of mosquito vectors is often hampered by the presence of morphologically indiscernible sibling species. The Maculipennis complex is one of these groups that include both malaria vectors of primary importance and species of low/negligible epidemiological relevance, of which distribution data in Italy are outdated. Our study was aimed at providing an updated distribution of Maculipennis complex in Northern Italy through the sampling and morphological/molecular identification of specimens from five regions. The most abundant species was Anopheles messeae (2032), followed by Anopheles maculipennis s.s. (418), Anopheles atroparvus (28) and Anopheles melanoon (13). Taking advantage of ITS2 barcoding, we were able to finely characterize tested mosquitoes, classifying all the Anopheles messeae specimens as Anopheles daciae, a taxon with debated rank to which we referred as species inquirenda (sp. inq.). The distribution of species was characterized by Ecological Niche Models (ENMs), fed by recorded points of presence. ENMs provided clues on the ecological preferences of the detected species, with An. daciae sp. inq. linked to stable breeding sites and An. maculipennis s.s. more associated to ephemeral breeding sites. We demonstrate that historical Anopheles malaria vectors are still present in Northern Italy.

Ticks infesting humans and associated pathogens: a cross-sectional study in a 3-year period (2017-2019) in northwest Italy.

BACKGROUND: Tick-borne diseases are common throughout Europe. Ticks transmit pathogens to the host while feeding and together with mosquitoes, they are major vectors of infectious agents worldwide. In recent years, there has been a marked increase in the incidence of tick-bite events and tick-borne disease in northwest Italy, but information on the prevalence of tick-borne pathogens in ticks removed from humans remains scarce. To fill this gap, we report here the prevalence of tick bites and tick-borne pathogens documented for humans in Piedmont, northwest Italy, in the 3-year period 2017-2019. METHODS: Ticks attached to humans during 2017-2019 were collected from residents of urban and rural area by physicians and veterinarians working with local veterinary agencies. All ticks (n = 1290) were morphologically identified to the species level. A subset of ticks removed from children (age 0-18 years) and the elderly (> 70 years), both age groups considered to be at-risk populations, was screened by biomolecular analysis to detect pathogens (e.g. Rickettsia spp., Borrelia spp., Anaplasma spp.). Pathogen identity was confirmed by Sanger sequencing. RESULTS: Ticks were taxonomically assigned to ten species of six genera (Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus). Most belonged to the genus Ixodes: 1009 ticks (78.22%) were classified as Ixodes ricinus. A subset of 500 ticks collected from the two at-risk populations were subjected to PCR assay to determine the presence of Rickettsia spp., Borrelia spp., and Anaplasma spp. The overall prevalence of infection was 22.8% (n = 114; 95% confidence interval [CI]: 19.19-26.73%), meaning that at least one pathogen was detected: Rickettsia spp. (prevalence 15%, n = 76; 95% CI 12.17-18.65%); Borrelia spp. (prevalence 6.4%, n = 32; 95% CI 4.42-8.92%); and Anaplasma spp. (prevalence 1.2%, n = 6; 95% CI 0.44-2.6%). CONCLUSIONS: Our data underline the importance of surveillance in the epidemiology of tick-borne diseases and the implementation of strategies to control tick infestation and associated pathogens.

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.