RESUMEN
Aedes koreicus Edwards, 1917 (Hulecoetomyia koreica) is a mosquito (Diptera: Culicidae) from Northeast Asia with a rapidly expanding presence outside its original native range. Over the years, the species has been discovered in several new countries, either spreading after first introduction or remaining localised to limited areas. Notably, recent studies have demonstrated the ability of the species to transmit zoonotic parasites and viruses both in the field and in laboratory settings. Combined with its invasive potential, the possible role of Ae. koreicus in pathogen transmission highlights the public health risks resulting from its invasion. In this study, we used a recently established population from Italy to investigate aspects of biology that influence reproductive success in Ae. koreicus: autogeny, mating behaviour, mating disruption by the sympatric invasive species Aedes albopictus Skuse, 1894, and the presence of the endosymbiont Wolbachia pipientis Hertig, 1936. Our laboratory population did not exhibit autogenic behaviour and required a bloodmeal to complete its ovarian cycle. When we exposed Ae. koreicus females to males of Ae. albopictus, we observed repeated attempts at insemination and an aggressive, disruptive mating behaviour initiated by male Ae. albopictus. Despite this, no sperm was identified in Ae. koreicus spermathecae. Wolbachia, an endosymbiotic bacterium capable of influencing mosquito reproductive behaviour, was not detected in this Ae. koreicus population and, therefore, had no effect on Ae. koreicus reproduction.
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Aedes , Femenino , Masculino , Animales , Reproducción , Inseminación , Italia , Biología , Especies Introducidas , Mosquitos VectoresRESUMEN
In spring 2022, Europe faced an unprecedented heatwave, increasing the risk of West Nile virus (WNV) outbreaks. As early as 7 June 2022, WNV was detected in Culex mosquitoes in northern Italy, and - in the following days - in two blood donors, a patient with encephalitis, wild birds and additional mosquito pools. Genome sequencing demonstrated co-circulation of WNV lineage 2 and a newly introduced WNV lineage 1, which was discovered in the region in 2021.
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Culex , Culicidae , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Animales , Brotes de Enfermedades , Humanos , Italia/epidemiología , Estaciones del Año , Fiebre del Nilo Occidental/diagnóstico , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/genéticaRESUMEN
The relevant ecological changes due to the anthropological pressure on the planet is causing reactions in the biological systems, which we must understand and characterize at the local scale to assist the adoption of suitable decisions in the public health risk management. The project presented in this paper is focused on the vector-borne diseases, mainly transmitted by mosquitoes. The species of mosquito currently playing an active role of public health importance in Italy are Aedes albopictus, as a vector of Chikungunya, Dengue and Zika viruses, as well as Culex pipiens, as a vector of West Nile and Usutu viruses. Predictive models are indicating the risk of introduction and establishment in the Mediterranean basin of Aedes aegypti, which is causing a mayor concern. The project has been conducted by the Emilia-Romagna, Piemonte, Veneto, Marche and Sicilia Regions, together with the Italian National Health Institute. The aim was to develop and pilot testing new approaches and technological tools possibly assisting the public health system in the management of the risk. The activities have been organized on six specific objectives: 1. Development and field testing of guidelines for the surveillance of invasive mosquito species; 2. Creation of risk maps for Chikungunya, Dengue and Zika viruses based on the quantitative monitoring of Aedes albopictus populations; 3. Shaping web platform models assisting the sharing of data from/to actors involved in the integrated surveillance of West Nile at the regional level; 4. Developing communication formats dealing with vector borne diseases addressing citizen and specific categories; 5. Approaching the cost-benefit analysis in the view to assist decision makers; 6. Sero-surveillance on arboviruses not included in the Ministry directive (Tick Borne Encephalitis and Toscana virus). The achieved results are presented and the acquired experience is made available to promote the adoptions on a larger scale of the approaches and methods to be certainly adapted in the specific contexts. The one health approach seems suitable to address the necessities emerging in this field by taking into consideration the different triggers shaping the dynamics we are observing.
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Aedes , Fiebre Chikungunya , Culex , Dengue , Infección por el Virus Zika , Virus Zika , Animales , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/prevención & control , Dengue/epidemiología , Dengue/prevención & control , Humanos , Italia/epidemiología , Mosquitos Vectores , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/prevención & controlRESUMEN
In August 2020, during the coronavirus disease (COVID-19) pandemic, five locally acquired cases of dengue virus type 1 were detected in a family cluster in Vicenza Province, North-East Italy where Aedes albopictus mosquitoes are endemic. The primary case was an importation from West Sumatra, Indonesia. This is the first outbreak of autochthonous dengue reported in Italy. During the COVID-19 pandemic, screening of febrile travelers from endemic countries is crucial in areas where competent vectors are present.
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Virus del Dengue/aislamiento & purificación , Dengue/diagnóstico , Viaje , Adulto , Preescolar , Dengue/epidemiología , Dengue/inmunología , Dengue/virología , Virus del Dengue/genética , Brotes de Enfermedades , Transmisión de Enfermedad Infecciosa , Femenino , Fiebre/etiología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Indonesia , Italia/epidemiología , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BackgroundUsutu virus (USUV) is a mosquito-borne flavivirus, which shares its transmission cycle with the phylogenetically related West Nile virus (WNV). USUV circulates in several European countries and its activity has increased over the last 5 years.AimTo describe human cases of USUV infection identified by surveillance for WNV and USUV infection in the Veneto Region of northern Italy in 2018.MethodsFrom 1 June to 30 November 2018, all cases of suspected autochthonous arbovirus infection and blood donors who had a reactive WNV nucleic acid test were investigated for both WNV and USUV infection by in-house molecular methods. Anti-WNV and anti-USUV IgM and IgG antibodies were detected by ELISA and in-house immunofluorescence assay, respectively; positive serum samples were further tested by WNV and USUV neutralisation assays run in parallel.ResultsEight cases of USUV infection (one with neuroinvasive disease, six with fever and one viraemic blood donor who developed arthralgia and myalgia) and 427 cases of WNV infection were identified. A remarkable finding of this study was the persistence of USUV RNA in the blood and urine of three patients during follow-up. USUV genome sequences from two patients shared over 99% nt identity with USUV sequences detected in mosquito pools from the same area and clustered within lineage Europe 2.ConclusionsClinical presentation and laboratory findings in patients with USUV infection were similar to those found in patients with WNV infection. Cross-reactivity of serology and molecular tests challenged the differential diagnosis.
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Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Culicidae/virología , Infecciones por Flavivirus/diagnóstico , Flavivirus/aislamiento & purificación , Vigilancia de la Población/métodos , Virus del Nilo Occidental/aislamiento & purificación , Animales , Diagnóstico Diferencial , Ensayo de Inmunoadsorción Enzimática , Flavivirus/genética , Infecciones por Flavivirus/epidemiología , Infecciones por Flavivirus/virología , Técnicas de Genotipaje , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Italia/epidemiología , Filogenia , Vigilancia de Guardia , Fiebre del Nilo Occidental/virología , Secuenciación Completa del GenomaRESUMEN
Based on 2015 abundance of Aedes albopictus in nine northern Italian municipalities with temperate continental/oceanic climate, we estimated the basic reproductive number R0 for Zika virus (ZIKV) to be systematically below the epidemic threshold in most scenarios. Results were sensitive to the value of the probability of mosquito infection after biting a viraemic host. Therefore, further studies are required to improve models and predictions, namely evaluating vector competence and potential non-vector transmissions.
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Aedes/virología , Epidemias/estadística & datos numéricos , Insectos Vectores/virología , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/virología , Virus Zika/aislamiento & purificación , Animales , Clima , Ecosistema , Humanos , Italia/epidemiología , Dinámica Poblacional , Prevalencia , Bosque Lluvioso , Medición de Riesgo , Factores de Riesgo , Virus Zika/clasificación , Virus Zika/patogenicidad , Infección por el Virus Zika/transmisiónRESUMEN
BACKGROUND: The invasive Asian tiger mosquito Aedes albopictus has dramatically expanded its distribution range, being catalogued as one of the world's 100 worst invasive alien species. As vectors of pathogens, Ae. albopictus may create novel epidemiological scenarios in the invaded areas. METHODS: Here, the frequency of encounters of Ae. albopictus with the avian malaria parasite Plasmodium and the related Haemoproteus was studied in an area with established populations in northeastern Italy and compared with those from four native mosquito species, Anopheles maculipennis s.l., Culex hortensis, Culex pipiens, and Ochlerotatus caspius. The abdomens of mosquitoes with a recent blood meal were used to identify both the blood meal source and the parasites harboured. RESULTS: Aedes albopictus had a clear antropophilic behaviour while An. maculipennis and Oc. caspius fed mainly on non-human mammals. Birds were the most common hosts of Cx. pipiens and reptiles of Cx. hortensis. Parasites were isolated from three mosquito species, with Cx. pipiens (30%) showing the highest parasite prevalence followed by Cx. hortensis (9%) and Ae. albopictus (5%). CONCLUSIONS: These results are the first identifying the avian malaria parasites harboured by mosquitoes in Italy and represent the first evidence supporting that, although Ae. albopictus could be involved in the transmission of avian malaria parasites, the risk of avian malaria parasite spread by this invasive mosquito in Europe would be minimal.
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Sangre/parasitología , Culicidae/fisiología , Culicidae/parasitología , Conducta Alimentaria , Haemosporida/aislamiento & purificación , Animales , Aves , Italia , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Estómago/parasitologíaRESUMEN
The seasonal and daily activity of mosquito vectors of pathogens affecting animals and humans were studied in northeastern Italy at a site within the Po River Delta Park. A CDC-CO2 trap and a gravid trap were operated at 2-h intervals for 24 h every 15 d from May to October 2010. Overall, 5,788 mosquitoes comprising six species were collected, namely Culex pipiens L. (75.1% of total), Aedes caspius (Pallas) (15.2%), Aedes vexans (Meigen) (6.9%), Anopheles maculipennis s.l. Meigen (2.6%), Culiseta annulata (Schrank) (0.2%), and Culex modestus Ficalbi (<0.1%). The relative abundance of these species increased from May until the beginning of July and then decreased, disappearing at the beginning of October. The diel host-seeking patterns and oviposition site-seeking patterns were species specific and were differentially affected by the ecological variables recorded at the day and hour of mosquito collection or two weeks before collection. Knowledge of the seasonal and daily host-seeking patterns of mosquitoes highlights the time periods of the day and the seasons of potential exposure for animals and humans to mosquito-borne pathogens, therefore delineating the best time for the application of preventive measures. Furthermore, knowledge of the oviposition site-seeking activity of the mosquitoes optimizes the capture of gravid females, thereby enhancing the likelihood of detecting pathogens.
Asunto(s)
Culicidae/fisiología , Insectos Vectores/fisiología , Oviposición , Estaciones del Año , Animales , Clima , Ecosistema , Conducta Alimentaria , Femenino , Italia , Masculino , Dinámica Poblacional , Especificidad de la EspecieRESUMEN
BACKGROUND: Since 2010 Veneto region (North-Eastern Italy) planned a special integrated surveillance of summer fevers to promptly identify cases of West Nile Fever (WNF), dengue (DENV) and chikungunya (CHIKV). The objectives of this study were (i) To increase the detection rate of imported CHIKV and DENV cases in travellers from endemic areas and promptly identify potential autochthonous cases.(ii) To detect autochthonous cases of WNF, besides those of West Nile Neuroinvasive Disease (WNND) that were already included in a national surveillance. METHODS: Human surveillance: a traveler who had returned within the previous 15 days from endemic countries, with fever >38°C, absence of leucocytosis (leukocyte count <10,000 µL), and absence of other obvious causes of fever, after ruling out malaria, was considered a possible case of CHIKV or DENV. A possible autochthonous case of WNF was defined as a patient with fever >38°C for <7 days, no recent travel history and absence of other obvious causes of fever. Entomologic surveillance: for West Nile (WNV) it was carried out from May through November placing CDC-CO2 traps in five provinces of Veneto Region, while for DENV and CHIKV it was also performed around residences of viremic cases. RESULTS: Human surveillance: between 2010 and 2012, 234 patients with fever after travelling were screened, of which 27 (11,5%) were found infected (24 with DENV and 3 with CHIKV). No autochthonous case of DENV or CHIKV was detected. Autochthonous patients screened for WNF were 408, and 24 (5,9%) were confirmed cases. Entomologic surveillance: the WNV was found in 10, 2 and 11 pools of Culex pipiens from 2010 to 2012 respectively, in sites of Rovigo, Verona, Venezia and Treviso provinces). No infected Aedes albopictus with DENV or CHIKV was found. CONCLUSIONS: Veneto is the only Italian region reporting WNV human cases every year since 2008. WNV is likely to cause sporadic cases and unforeseeable outbreaks for decades. Including WNF in surveillance provides additional information and possibly an early alert system. Timely detection of DENV and CHIKV should prompt vector control measures to prevent local outbreaks.
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Infecciones por Alphavirus/epidemiología , Culicidae/clasificación , Dengue/epidemiología , Monitoreo Epidemiológico , Insectos Vectores/virología , Fiebre del Nilo Occidental/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones por Alphavirus/virología , Animales , Fiebre Chikungunya , Virus Chikungunya/genética , Virus Chikungunya/aislamiento & purificación , Culicidae/virología , Dengue/virología , Virus del Dengue/genética , Virus del Dengue/aislamiento & purificación , Femenino , Enfermedades de los Caballos/epidemiología , Caballos , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Viaje , Fiebre del Nilo Occidental/veterinaria , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/genética , Virus del Nilo Occidental/aislamiento & purificación , Adulto JovenRESUMEN
BACKGROUND: Ixodes inopinatus was described from Spain on the basis of morphology and partial sequencing of 16S ribosomal DNA. However, several studies suggested that morphological differences between I. inopinatus and Ixodes ricinus are minimal and that 16S rDNA lacks the power to distinguish the two species. Furthermore, nuclear and mitochondrial markers indicated evidence of hybridization between I. inopinatus and I. ricinus. In this study, we tested our hypothesis on tick dispersal from North Africa to Southern Europe and determined the prevalence of selected tick-borne pathogens (TBPs) in I. inopinatus, I. ricinus, and their hybrids. METHODS: Ticks were collected in Italy and Algeria by flagging, identified by sequencing of partial TROSPA and COI genes, and screened for Borrelia burgdorferi s.l., B. miyamotoi, Rickettsia spp., and Anaplasma phagocytophilum by polymerase chain reaction and sequencing of specific markers. RESULTS: Out of the 380 ticks, in Italy, 92 were I. ricinus, 3 were I. inopinatus, and 136 were hybrids of the two species. All 149 ticks from Algeria were I. inopinatus. Overall, 60% of ticks were positive for at least one TBP. Borrelia burgdorferi s.l. was detected in 19.5% of ticks, and it was significantly more prevalent in Ixodes ticks from Algeria than in ticks from Italy. Prevalence of Rickettsia spotted fever group (SFG) was 51.1%, with significantly greater prevalence in ticks from Algeria than in ticks from Italy. Borrelia miyamotoi and A. phagocytophilum were detected in low prevalence (0.9% and 5.2%, respectively) and only in ticks from Italy. CONCLUSIONS: This study indicates that I. inopinatus is a dominant species in Algeria, while I. ricinus and hybrids were common in Italy. The higher prevalence of B. burgdorferi s.l. and Rickettsia SFG in I. inopinatus compared with that in I. ricinus might be due to geographical and ecological differences between these two tick species. The role of I. inopinatus in the epidemiology of TBPs needs further investigation in the Mediterranean Basin.
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Ixodes , Rickettsia , Animales , Ixodes/microbiología , Italia/epidemiología , Argelia/epidemiología , Rickettsia/aislamiento & purificación , Rickettsia/genética , Rickettsia/clasificación , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/microbiología , Prevalencia , Borrelia/genética , Borrelia/aislamiento & purificación , Borrelia/clasificación , Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/aislamiento & purificación , Anaplasma phagocytophilum/clasificación , Femenino , Hibridación Genética , Masculino , ARN Ribosómico 16S/genética , Borrelia burgdorferi/genética , Borrelia burgdorferi/aislamiento & purificación , Borrelia burgdorferi/clasificaciónRESUMEN
The frequency of locally transmitted dengue virus (DENV) infections has increased in Europe in recent years, facilitated by the invasive mosquito species Aedes albopictus, which is well established in a large area of Europe. In Italy, the first indigenous dengue outbreak was reported in August 2020 with 11 locally acquired cases in the Veneto region (northeast Italy), caused by a DENV-1 viral strain closely related to a previously described strain circulating in Singapore and China. In this study, we evaluated the vector competence of two Italian populations of Ae. albopictus compared to an Ae. aegypti lab colony. We performed experimental infections using a DENV-1 strain that is phylogenetically close to the strain responsible for the 2020 Italian autochthonous outbreak. Our results showed that local Ae. albopictus is susceptible to infection and is able to transmit the virus, confirming the relevant risk of possible outbreaks starting from an imported case.
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Aedes , Virus del Dengue , Dengue , Animales , Humanos , Dengue/epidemiología , Brotes de EnfermedadesRESUMEN
BACKGROUND: Estimates of the spatiotemporal distribution of different mosquito vector species and the associated risk of transmission of arboviruses are key to design adequate policies for preventing local outbreaks and reducing the number of human infections in endemic areas. In this study, we quantified the abundance of Aedes albopictus and Aedes aegypti and the local transmission potential for three arboviral infections at an unprecedented spatiotemporal resolution in areas where no entomological surveillance is available. METHODS: We developed a computational model to quantify the daily abundance of Aedes mosquitoes, leveraging temperature and precipitation records. The model was calibrated on mosquito surveillance data collected in 115 locations in Europe and the Americas between 2007 and 2018. Model estimates were used to quantify the reproduction number of dengue virus, Zika virus, and chikungunya in Europe and the Americas, at a high spatial resolution. FINDINGS: In areas colonised by both Aedes species, A aegypti was estimated to be the main vector for the transmission of dengue virus, Zika virus, and chikungunya, being associated with a higher estimate of R0 when compared with A albopictus. Our estimates highlighted that these arboviruses were endemic in tropical and subtropical countries, with the highest risks of transmission found in central America, Venezuela, Colombia, and central-east Brazil. A non-negligible potential risk of transmission was also estimated for Florida, Texas, and Arizona (USA). The broader ecological niche of A albopictus could contribute to the emergence of chikungunya outbreaks and clusters of dengue autochthonous cases in temperate areas of the Americas, as well as in mediterranean Europe (in particular, in Italy, southern France, and Spain). INTERPRETATION: Our results provide a comprehensive overview of the transmission potential of arboviral diseases in Europe and the Americas, highlighting areas where surveillance and mosquito control capacities should be prioritised. FUNDING: EU and Ministero dell'Università e della Ricerca, Italy (Piano Nazionale di Ripresa e Resilienza Extended Partnership initiative on Emerging Infectious Diseases); EU (Horizon 2020); Ministero dell'Università e della Ricerca, Italy (Progetti di ricerca di Rilevante Interesse Nazionale programme); Brazilian National Council of Science, Technology and Innovation; Ministry of Health, Brazil; and Foundation of Research for Minas Gerais, Brazil.
Asunto(s)
Aedes , Arbovirus , Fiebre Chikungunya , Infección por el Virus Zika , Virus Zika , Humanos , Animales , Fiebre Chikungunya/epidemiología , Europa (Continente)/epidemiología , Infección por el Virus Zika/epidemiologíaRESUMEN
Modelling approaches play a crucial role in supporting local public health agencies by estimating and forecasting vector abundance and seasonality. However, the reliability of these models is contingent on the availability of standardized, high-quality data. Addressing this need, our study focuses on collecting and harmonizing egg count observations of the mosquito Aedes albopictus, obtained through ovitraps in monitoring and surveillance efforts across Albania, France, Italy, and Switzerland from 2010 to 2022. We processed the raw observations to obtain a continuous time series of ovitraps observations allowing for an extensive geographical and temporal coverage of Ae. albopictus population dynamics. The resulting post-processed observations are stored in the open-access database VectAbundance.This initiative addresses the critical need for accessible, high-quality data, enhancing the reliability of modelling efforts and bolstering public health preparedness.
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Aedes , Animales , Bases de Datos Factuales , Mosquitos Vectores , Dinámica Poblacional , Francia , Albania , Suiza , ItaliaRESUMEN
Insects are, by far, the most common animals on our planet. The ubiquity and plethora of ecological niches occupied by insects, along with the strict and sometimes forced coexistence between insects and humans, make insects a target of public health interest. This article reports the negative aspects historically linked to insects as pests and vectors of diseases, and describes their potential as bioindicators of environmental pollution, and their use as food and feed. Both negative and positive impacts of insects on human and animal health need to be addressed by public health professionals who should aim to strike a balance within the wide range of sometimes conflicting goals in insect management, such as regulating their production, exploiting their potential, protecting their health and limiting their negative impact on animals and humans. This requires increased insect knowledge and strategies to preserve human health and welfare. The aim of this paper is to provide an overview of traditional and emerging topics bridging insects and public health to highlight the need for professionals, to address these topics during their work. The present and future role and activities of public health authorities regarding insects are analyzed.
RESUMEN
BACKGROUND: Aedes koreicus is a mosquito species native to East Asia which has recently invaded several countries in Europe. In Italy, this mosquito was first detected in the North-East in 2011 and is now widely distributed in the entire northern part of the country. The development of specific genetic markers, such as microsatellites, is necessary to uncover the dispersal routes of this mosquito from its native areas and, eventually, to plan future control interventions. METHODS: Available raw sequences of genomic DNA of Ae. koreicus were screened in silico using BLASTn to identify possible microsatellite-containing sequences. Specific primer pairs were then designed, and their efficiency was determined through polymerase chain reaction (PCR) on 32 individuals of Ae. koreicus collected in Italy. PCR conditions were optimised in three multiplex reactions. Genotyping of individual mosquitoes was performed on both single and multiplex PCR reactions. Finally, analysis of intra-population variation was performed to assess the level of polymorphism of the markers. RESULTS: Mosquito genotyping provided consistent results in both single and multiplex reactions. Out of the 31 microsatellite markers identified in the Ae. koreicus genome raw sequences, 11 were polymorphic in the examined mosquito samples. CONCLUSIONS: The results show that the 11 microsatellite markers developed here hold potential for investigating the genetic structure of Ae. koreicus populations. These markers could thus represent a novel and useful tool to infer the routes of invasion of this mosquito species into Europe and other non-native areas.
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Aedes , Humanos , Animales , Aedes/genética , Europa (Continente) , Italia , Polimorfismo Genético , Repeticiones de Microsatélite , Mosquitos Vectores/genética , Especies IntroducidasRESUMEN
Early detection of pathogens in vectors is important in preventing the spread of arboviral diseases, providing a timely indicator of pathogen circulation before outbreaks occur. However, entomological surveillance may face logistical constraints, such as maintaining the cold chain, and resource limitations, such as the field and laboratory workload of mosquito processing. We propose an FTA card-based trapping system that aims to simplify both field and laboratory phases of arbovirus surveillance. We modified a BG-Sentinel trap to include a mosquito collection chamber and a sugar feeding source through an FTA card soaked in a long-lasting viscous solution of honey and hydroxy-cellulose hydrogel. The FTA card ensures environmental preservation of nucleic acids, allowing continuous collection and feeding activity of specimens for several days and reducing the effort required for viral detection. We tested the trap prototype during two field seasons (2019 and 2021) in North-eastern Italy and compared it to CDC-CO2 trapping applied in West Nile and Usutu virus regional surveillance. Collections by the BG-FTA approach detected high species diversity, including Culex pipiens, Aedes albopictus, Culex modestus, Anopheles maculipennis sensu lato and Ochlerotatus caspius. When used for two-days sampling, the BG-FTA trap performed equally to CDC also for the WNV-major vector Cx. pipiens. The FTA cards detected both WNV and USUV, confirming the reliability of this novel approach to detect viral circulation in infectious mosquitoes. We recommend this surveillance approach as a particularly useful alternative in multi-target surveillance, for sampling in remote areas and in contexts characterized by high mosquito densities and diversity.
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Aedes , Infecciones por Arbovirus , Culex , Flavivirus , Virus del Nilo Occidental , Animales , Reproducibilidad de los Resultados , Mosquitos Vectores , Infecciones por Arbovirus/diagnósticoRESUMEN
Aedes japonicus and Aedes koreicus are two invasive mosquitoes native to East Asia that are quickly establishing in temperate regions of Europe. Both species are vectors of arboviruses, but we currently lack a clear understanding of their evolution. Here, we present new short-read, shallow genome sequencing of A. japonicus and A. koreicus individuals from northern Italy, which we used for downstream phylogenetic and barcode analyses. We explored associated microbial DNA and found high occurrences of Delftia bacteria in both samples, but neither Asaia nor Wolbachia. We then assembled complete mitogenomes and used these data to infer divergence times estimating the split of A. japonicus from A. koreicus in the Oligocene, which was more recent than that previously reported using mitochondrial markers. We recover a younger age for most other nodes within Aedini and other Culicidae. COI barcoding and phylogenetic analyses indicate that A. japonicus yaeyamensis, A. japonicus amamiensis, and the two A. koreicus sampled from Europe should be considered as separate species within a monophyletic species complex. Our studies further clarify the evolution of A. japonicus and A. koreicus, and indicate the need to obtain whole-genome data from putative species in order to disentangle their complex patterns of evolution.
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In 2010, in Veneto Region, Italy, surveillance of summer fevers was conducted to promptly identify autochthonous cases of West Nile fever and increase detection of imported dengue and chikungunya in travelers. Surveillance highlighted the need to modify case definitions, train physicians, and when a case is identified, implement vector control measures.
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Infecciones por Alphavirus/diagnóstico , Dengue/diagnóstico , Vigilancia de la Población , Fiebre del Nilo Occidental/diagnóstico , Infecciones por Alphavirus/epidemiología , Infecciones por Alphavirus/virología , Anticuerpos Antivirales/sangre , Fiebre Chikungunya , Virus Chikungunya/genética , Dengue/epidemiología , Dengue/virología , Virus del Dengue/genética , Humanos , Italia/epidemiología , Patología Molecular , Reacción en Cadena en Tiempo Real de la Polimerasa , Viaje , Fiebre del Nilo Occidental/epidemiologíaRESUMEN
Despite the eradication of malaria across most European countries in the 1960s and 1970s, the anopheline vectors are still present. Most of the malaria cases that have been reported in Europe up to the present time have been infections acquired in endemic areas by travelers. However, the possibility of acquiring malaria by locally infected mosquitoes has been poorly investigated in Europe, despite autochthonous malaria cases having been occasionally reported in several European countries. Here we present an update on the occurrence of potential malaria vector species in Europe. Adopting a systematic review approach, we selected 288 papers published between 2000 and 2021 for inclusion in the review based on retrieval of accurate information on the following Anopheles species: An. atroparvus, An. hyrcanus sensu lato (s.l.), An. labranchiae, An. maculipennis sensu stricto (s.s.), An. messeae/daciae, An. sacharovi, An. superpictus and An. plumbeus. The distribution of these potential vector species across Europe is critically reviewed in relation to areas of major presence and principal bionomic features, including vector competence to Plasmodium. Additional information, such as geographical details, sampling approaches and species identification methods, are also reported. We compare the information on each species extracted from the most recent studies to comparable information reported from studies published in the early 2000s, with particular reference to the role of each species in malaria transmission before eradication. The picture that emerges from this review is that potential vector species are still widespread in Europe, with the largest diversity in the Mediterranean area, Italy in particular. Despite information on their vectorial capacity being fragmentary, the information retrieved suggests a re-definition of the relative importance of potential vector species, indicating An. hyrcanus s.l., An. labranchiae, An. plumbeus and An. sacharovi as potential vectors of higher importance, while An. messeae/daciae and An. maculipennis s.s. can be considered to be moderately important species. In contrast, An. atroparvus and An. superpictus should be considered as vectors of lower importance, particularly in relation to their low anthropophily. The presence of gaps in current knowledge of vectorial systems in Europe becomes evident in this review, not only in terms of vector competence but also in the definition of sampling approaches, highlighting the need for further research to adopt the appropriate surveillance system for each species.
Asunto(s)
Anopheles , Malaria , Animales , Ecología , Europa (Continente)/epidemiología , Malaria/epidemiología , Malaria/prevención & control , Mosquitos VectoresRESUMEN
Aedes koreicus is an invasive mosquito species which has been introduced into several European countries. Compared to other invasive Aedes mosquitoes, little is known of its biology and ecology. To determine Ae. koreicus' vectorial capacity, it is essential to establish its feeding patterns and level of anthropophagy. We report on the blood-feeding patterns of Ae. koreicus, examining the blood meal origin of engorged females and evaluating the influence of different biotic and abiotic factors on feeding behavior. Mosquitoes were collected in 23 sites in northern Italy by manual aspiration and BG-sentinel traps; host availability was estimated by survey. The source of blood meals was identified using a nested PCR and by targeting and sequencing the cytochrome c oxidase subunit I gene. In total, 352 Ae. koreicus engorged females were collected between 2013 and 2020 and host blood meals were determined from 299 blood-fed mosquitoes (84.9%). Eleven host species were identified, with the highest prevalences being observed among roe deer (Capreolus capreolus) (N = 189, 63.2%) and humans (N = 46, 15.4%). Blood meals were mostly taken from roe deer in forested sites and from humans in urban areas, suggesting that this species can feed on different hosts according to local abundance. Two blood meals were identified from avian hosts and one from lizard. Ae. koreicus' mammalophilic feeding pattern suggests that it may be a potential vector of pathogens establishing transmission cycles among mammals, whereas its role as a bridge vector between mammals and birds could be negligible.