ABSTRACT
BACKGROUND: The European region achieved interruption of malaria transmission during the 1970s. Since then, malaria control programs were replaced by surveillance systems in order to prevent possible re-emergence of this disease. Sporadic cases of non-imported malaria were recorded in several European countries in the past decade and locally transmitted outbreaks of Plasmodium vivax, most probably supported by Anopheles sacharovi, have been repeatedly reported from Greece since 2009. The possibility of locally-transmitted malaria has been extensively studied in Italy where the former malaria vector An. labranchiae survived the control campaign which led to malaria elimination. In this study, we present paradigmatic cases that occurred during a 2017 unusual cluster, which caused strong concern in public opinion and were carefully investigated after the implementation of the updated malaria surveillance system. METHODS: For suspected locally-transmitted malaria cases, alerts to Ministry of Health (MoH) and the National Institute of Health (ISS) were mandated by the Local Health Services (LHS). Epidemiological investigations on the transmission modes and the identification of possible infection's source were carried out by LHS, MoH and ISS. Entomological investigations were implemented locally for all suspected locally-transmitted cases that occurred in periods suitable to anopheline activity. Molecular diagnosis by nested-PCR for the five human Plasmodium species was performed to support microscopic diagnosis. In addition, genotyping of P. falciparum isolate was carried out to investigate putative sources of infection and transmission modalities. RESULTS: In 2017, a cluster of seven non-imported cases was recorded from August through October. Among them, P. ovale curtisi was responsible of one case whereas six cases were caused by P. falciparum. Two cases were proved to be nosocomial while the other five were recorded as cryptic at the end of epidemiological investigations. CONCLUSIONS: The epidemiological evidence shows that the locally acquired events are sporadic, often remain unresolved and classified as cryptic ones despite investigative efforts. The "cluster" of seven non-imported cases that occurred in 2017 in different regions of Italy therefore represents a conscious alert that should lead us to maintain a constant level of surveillance in a former malaria endemic country.
Subject(s)
Disease Outbreaks/statistics & numerical data , Malaria, Falciparum/epidemiology , Malaria/epidemiology , Mosquito Vectors , Population Surveillance , Animals , Female , Humans , Italy/epidemiology , Malaria, Falciparum/microbiology , Malaria, Falciparum/transmission , Male , Plasmodium falciparum/isolation & purification , Plasmodium ovale/isolation & purification , Polymerase Chain ReactionABSTRACT
We detected Crimean-Congo hemorrhagic fever virus in a Hyalomma rufipes nymph collected from a whinchat (Saxicola rubetra) on the island of Ventotene in April 2017. Partial genome sequences suggest the virus originated in Africa. Detection of the genome of this virus in Italy confirms its potential dispersion through migratory birds.
Subject(s)
Bird Diseases/transmission , Bird Diseases/virology , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/veterinary , Ticks/virology , Animals , Birds , Genes, Viral , Genome, Viral , Hemorrhagic Fever Virus, Crimean-Congo/classification , Hemorrhagic Fever Virus, Crimean-Congo/isolation & purification , Humans , Italy/epidemiology , PhylogenyABSTRACT
In 2017, a chikungunya outbreak in central Italy later evolved into a secondary cluster in southern Italy, providing evidence of disease emergence in new areas. Officials have taken action to raise awareness among clinicians and the general population, increase timely case detection, reduce mosquito breeding sites, and promote mosquito bite prevention.
Subject(s)
Chikungunya Fever/epidemiology , Chikungunya Fever/transmission , Chikungunya virus , Disease Outbreaks , Chikungunya Fever/history , Chikungunya Fever/virology , Disease Transmission, Infectious , Geography , History, 21st Century , Humans , Italy/epidemiology , Mosquito Vectors/virologyABSTRACT
BACKGROUND: Europe and Italy were declared malaria free since the 1970s although the presence of competent vectors and the high number of yearly imported malaria cases make this disease a potential rising health issue. In September 2017, a cryptic fatal case of Plasmodium falciparum malaria in the Province of Trento, Italy, raised the concern of health authorities on the possible resurgence of this disease in the Mediterranean Basin. METHODS: An entomological surveillance by means of BG traps, CDC light traps and larval search was performed. Sites were chosen among urban and suburban environments (e.g. private houses, public parks, schools, cemeteries, ecotone urban/forest, farms), ranging from an altitude of 91 to 1332 m above sea level. All the mosquitoes collected were morphologically identified and about half of them (103; 49%) were confirmed with the sequencing analysis of the rRNA internal transcribed spacer 2 (ITS-2). RESULTS: In the present study 287 sites were screened for the presence of Anopheles spp. and 211 specimens were collected and identified. Hundred-eighteen individuals (56%) belonged to Anopheles plumbeus, 56 (26.5%) to Anopheles maculipennis complex, 10 (4.7%) to Anopheles claviger and 27 were identified only at genus level. This is the first record for the presence of An. plumbeus in the study area. CONCLUSIONS: The presence of Anopheles spp. mosquitoes in the Province of Trento, Italy, has been updated with the occurrence of An. plumbeus. The risk of malaria endemicity in the area is to be considered very low, but urban and peri-urban habitat may act as potential breeding sites for the presence of mosquito vectors and should be constantly monitored.
Subject(s)
Anopheles/genetics , Anopheles/parasitology , Malaria, Falciparum/epidemiology , Mosquito Vectors/parasitology , Animal Distribution , Animals , DNA, Protozoan/genetics , DNA, Ribosomal Spacer/genetics , Epidemiological Monitoring , Female , Genes, rRNA , Italy/epidemiology , Larva/parasitology , Male , Plasmodium falciparumABSTRACT
We compared the vector competence of an Italian population of Aedes albopictus for two strains of chikungunya virus (CHIKV), with and without E1:A226V mutation, responsible for outbreaks in 2007 in the Emilia Romagna region and 2017 in the Lazio and Calabria regions, respectively. Ae. albopictus showed similar vector competence for both viral strains indicating that E1:A226V mutation is not exclusively responsible for ability of CHIKV to replicate well in this mosquito species.
Subject(s)
Aedes/virology , Alphavirus Infections/transmission , Chikungunya Fever/virology , Chikungunya virus/genetics , Chikungunya virus/pathogenicity , Mosquito Vectors/virology , Mutation/genetics , Aedes/physiology , Alphavirus Infections/epidemiology , Animals , Chikungunya Fever/diagnosis , Chikungunya Fever/epidemiology , Chikungunya virus/isolation & purification , Disease Outbreaks , Disease Vectors , Humans , Indian Ocean , Italy/epidemiology , Mosquito Vectors/physiology , RNA, Viral/analysis , Species SpecificityABSTRACT
An autochthonous chikungunya outbreak is ongoing near Anzio, a coastal town in the province of Rome. The virus isolated from one patient and mosquitoes lacks the A226V mutation and belongs to an East Central South African strain. As of 20 September, 86 cases are laboratory-confirmed. The outbreak proximity to the capital, its late summer occurrence, and diagnostic delays, are favouring transmission. Vector control, enhanced surveillance and restricted blood donations are being implemented in affected areas.
Subject(s)
Aedes/virology , Chikungunya Fever/diagnosis , Chikungunya virus/genetics , Chikungunya virus/isolation & purification , Disease Outbreaks , Animals , Antibodies, Viral , Chikungunya Fever/epidemiology , Chikungunya Fever/prevention & control , Disease Outbreaks/prevention & control , Female , Humans , Insect Vectors/virology , Italy/epidemiology , Phylogeny , Polymerase Chain Reaction , Viral Envelope Proteins/geneticsABSTRACT
We investigated the susceptibility of an Italian population of Culex pipiens mosquitoes to Zika virus (ZIKV) infection, tested in parallel with Aedes aegypti, as a positive control. We analysed mosquitoes at 0, 3, 7, 10, 14, 20 and 24 days after an infectious blood meal. Viral RNA was detected in the body of Cx. pipiens up to three days post-infection, but not at later time points. Our results indicate that Cx. pipiens is not susceptible to ZIKV infection.
Subject(s)
Aedes/virology , Culex/virology , Insect Vectors/virology , Zika Virus Infection/transmission , Zika Virus/isolation & purification , Zika Virus/pathogenicity , Animals , Disease Susceptibility , Female , Real-Time Polymerase Chain Reaction , Viral Load , Zika Virus/genetics , Zika Virus Infection/virologyABSTRACT
We report a study on vector competence of an Italian population of Aedes albopictus for Zika virus (ZIKV). Ae. albopictus was susceptible to ZIKV infection (infection rate: 10%), and the virus could disseminate and was secreted in the mosquito's saliva (dissemination rate: 29%; transmission rate: 29%) after an extrinsic incubation period of 11 days. The observed vector competence was lower than that of an Ae. aegypti colony tested in parallel.
Subject(s)
Aedes/virology , Animal Structures/virology , Mosquito Vectors/virology , Saliva/virology , Zika Virus Infection/virology , Zika Virus/isolation & purification , Animals , Female , Humans , Italy , Viral Load , Zika Virus/pathogenicityABSTRACT
Knowledge about soft ticks (Ixodida: Argasidae) in Sardinia is incomplete and distribution data need to be updated. This work studies soft ticks on the island focusing on two species, Argas reflexus and Ornithodoros maritimus, both recently recorded. A total number of 12 specimens of these species of interest were collected between 2004 and 2015. This study reports for the first time the presence of O. maritimus in a coastal area in Italy, and more generally in a coastal area rather than small islands near the coastline, confirming the presence of this species on the island 20 years after its last recording. Moreover we confirm the presence of A. reflexus on the island, in the town of Cagliari and, for the first time, in the town of Quartu Sant'Elena. At the present state of knowledge, in Sardinia, Ornithodoros erraticus, which was actively looked for within the surveillance for African swine fever, an endemic disease since 1978 on the island, is not present. The presence of another species reported only once in Sardinia, Argas vespertilionis, needs further confirmation.
Subject(s)
Animal Distribution , Argasidae/classification , Argasidae/physiology , Animals , ItalyABSTRACT
BACKGROUND: Anopheles sacharovi, a member of the Anopheles maculipennis complex, was a historical malaria vector in Italy, no longer found since the last report at the end of 1960s. In September 2022, within the Surveillance Project for the residual anophelism, a single specimen of An. maculipennis sensu lato collected in Lecce municipality (Apulia region) was molecularly identified as An. sacharovi. This record led to implement a targeted entomological survey in September 2023. METHODS: Investigation was conducted in the areas around the first discovery, focusing on animal farms, riding stables and potential breeding sites. Adult and immature mosquitoes were collected, using active search or traps, in several natural and rural sites. Mosquitoes belonging to An. maculipennis complex were identified morphologically and molecularly by a home-made routine quantitative polymerase chain reaction (qPCR) assay, developed specifically for the rapid identification of An. labranchiae, and, when necessary, by amplification and sequencing of the ITS-2 molecular marker. RESULTS: Out of the 11 sites investigated, 6 were positive for Anopheles presence. All 20 An. maculipennis s.l. (7 adults, 10 larvae and 3 pupae) collected in the areas were identified as An. sacharovi by ITS-2 sequencing. CONCLUSIONS: The discovery of An. sacharovi, considered to have disappeared from Italy for over 50 years, has a strong health relevance and impact, highlighting an increase in the receptivity of the southern areas. As imported malaria cases in European countries are reported every year, the risk of Plasmodium introduction by gametocyte carriers among travellers from endemic countries should be taken into greater consideration. Our findings allow rethinking and building new models for the prediction and expansion of introduced malaria. Furthermore, to prevent the risk of reintroduction of the disease, the need to strengthen the surveillance of residual anophelism throughout the South should be considered.
Subject(s)
Anopheles , Malaria , Animals , Malaria/epidemiology , Anopheles/genetics , Mosquito Vectors , Italy/epidemiology , EuropeABSTRACT
Migratory birds play an important role in transporting ixodid ticks and tick-borne pathogens between continents. During the Boreal spring, migratory birds reach Europe, mainly from sub-Saharan Africa or from northern African countries but not much is known about the diversity and ecology of the ticks they spread. From 2017 to 2022, in the framework of two consecutive projects focused on sampling migratory birds from Africa to Europe, a total of 27 immature Amblyomma ticks were collected from migratory birds, belonging to 8 species, captured on the Island of Ventotene, an important stop-over site in the Mediterranean Sea. In the absence of adult specimens, morphological identification was limited to assigning these ticks to the Amblyomma genus. In this study, sequencing and comparative analysis of three mitochondrial molecular markers (12S rDNA, 16S rDNA, COI) were performed to achieve taxonomic identification. Sequences obtained from Ventotene specimens matched at 100% identity with Amblyomma sparsum. In conclusion, this study documented that immature stages of this species belonging to the Amblyomma marmoreum complex reached the Pontine Islands for six consecutive years. The entry of alien tick species and their potentially transmitted pathogens deserves further study, also in light of the globally ongoing climate change.
ABSTRACT
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.
Subject(s)
Aedes , Dengue Virus , Dengue , Animals , Humans , Dengue/epidemiology , Disease OutbreaksABSTRACT
The role of migratory birds in circulation tick-borne viruses needs to be better defined. In order to assess the potential role of migratory birds in exotic virus spread, we conducted a study to identify ticks collected from migratory birds in the Central Region of Italy, and performed molecular investigation for Crimea-Congo Hemorrhagic Fever (CCHFV), West Nile fever (WNFV) and Usutu (USUV) in the vectors. A total of 137 competent ticks were collected with predominance of Hyalomma species. Although, negative results were obtained for all viruses considered, the high proportion of Hyalomma ticks highlights the potential risk for the dissemination of tick-borne viruses through infested migratory birds.
Subject(s)
Arachnid Vectors/virology , Birds/parasitology , Hemorrhagic Fever Virus, Crimean-Congo/isolation & purification , Ticks/virology , West Nile virus/isolation & purification , Animal Migration , Animals , Arachnid Vectors/classification , Birds/physiology , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever Virus, Crimean-Congo/radiation effects , Italy , Phylogeny , Ticks/classification , West Nile virus/geneticsABSTRACT
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.
Subject(s)
Aedes , Arbovirus Infections , Culex , Flavivirus , West Nile virus , Animals , Reproducibility of Results , Mosquito Vectors , Arbovirus Infections/diagnosisABSTRACT
The role of migratory birds in the spread of ticks and tick-borne pathogens along their routes from Africa to Europe is increasingly emerging. Wild birds can host several tick species, often infected by bacteria responsible for zoonoses. The aim of the study is to assess the possible introduction of exotic ticks carried by migratory birds into Italy from Africa and to detect the presence of Rickettsia species and Coxiella burnetii they may harbor. During a two-year survey, we collected ticks from migratory birds captured during their short stop-over on Ventotene Island. Specimens were first identified by morphology or sequencing molecular targets when needed, and then tested by real-time PCR for the presence of selected pathogens. A total of 91% of the collection consisted of sub-Saharan ticks, more than 50% of which were infected by Rickettsia species belonging to the spotted fever group, mainly represented by R. aeschlimannii. In contrast, the suspected C. burnetii detected in two soft ticks were confirmed as Coxiella-like endosymbionts and not the pathogen. Although there are still gaps in the knowledge of this dispersal process, our findings confirm the role of migratory birds in the spread of ticks and tick-borne pathogens, suggesting the need for a continuous surveillance to monitor the potential emergence of new diseases in Europe.
ABSTRACT
Anopheles algeriensis Theobald, 1903, considered a competent vector of Plasmodium parasites, is a mosquito species widely distributed in the Mediterranean area but rare in Northern and Central Europe. The disappearance of its suitable breeding sites in Italy is having a detrimental effect on the occurrence of this species once common along the Southern coasts and on the islands. Recently, molecular investigations have renewed interest in this species, highlighting a genetic heterogeneity among European populations. In this study, An. algeriensis populations from Italy, Germany, Romania, and Sweden were analyzed by molecular typing of the intergenic transcribed spacer 2 (ITS2). The mitochondrial cytochrome c oxidase subunit I (COI) was also analyzed from specimens collected in Southern Italy. With the aim of investigating the population structure of this species, the obtained data were compared to all publicly available ITS2 and COI sequences of An. algeriensis, adding specimens from Spain and Portugal. The analyses of both markers indicate a split between Iberian populations (Spain for ITS2 and Spain/Portugal for COI) and those from the rest of Europe, revealing two cryptic species. The analysis of the COI barcode revealed a third clade representing a cryptic species present in Danube Delta (Romania). The high levels of genetic divergence among the clades of An. algeriensis indicate that this taxon represents a species complex, potentially harboring several distinct cryptic species.
ABSTRACT
The annual movements of migratory birds can contribute to the spread of African ticks and tick-borne pathogens of potential public health concern across Europe. The aim of the study was to investigate their role in the possible introduction of African ticks and tick-borne pathogens into European countries during spring migration. A total of 2344 ticks were collected during three spring seasons from 1079 birds captured on three Italian stop-over islands during their northbound migration. Once identified, each tick was tested by RT-PCR for the presence of Crimean-Congo hemorrhagic fever (CCHFV), West Nile (WNV), and Usutu (USUV) viruses. Moreover, carcasses of birds found dead were collected and tested for the possible presence of WNV and USUV. Results confirmed a higher contribution of trans-Saharan migrants compared to intra-Palearctic ones and the prevalence of African tick species in the sample. CCHFV was detected for the second time in Italy in a Hyalomma rufipes, and WNV was found in two ticks of the same genus, all carried by trans-Saharan birds. WNV lineage 1 was also found in the organs of a Garden warbler. These results confirm the role of migratory birds in carrying African ticks, as well as viruses of zoonotic importance, from Africa into Europe.
ABSTRACT
BACKGROUND: There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. METHODS: Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatellite loci and geometric morphometrics on 21 wing landmarks. RESULTS: Levels of genetic diversity were comparable to those reported for tropical malaria vectors. Low levels of genetic (0.004 Subject(s)
Anopheles/genetics
, Anopheles/physiology
, Genetic Variation
, Animals
, Anopheles/classification
, Europe
, Geography
, Microsatellite Repeats
, Wings, Animal/anatomy & histology
ABSTRACT
The first record of Ornithodoros (Alectorobius) coniceps (Canestrini) was reported for Italy in 1877, inside the interstices of the ancient mosaics at S. Marco Basilica in Venice. Afterwards only few discoveries of the species are reported for Italy; the last record is dated back to 1984, in L'Aquila town (Abruzzo Region). The present study shows the data of a survey carried out as a result of a massive infestation by O. coniceps in an ancient villa in Anzio town (Latium region) recently restored. In the past decades the villa has been fallen into disrepair, becoming an occasional shelter for wild animals mainly pigeons, that colonized the whole building for generations. This case appears worthy of note because it is the first record of this species after more than 25 years in Italy. A total of 136 specimens were collected by three methods: manual, mechanical aspirators and Wilson traps. Wilson trapping indicates positive O. coniceps tropism for CO(2).
Subject(s)
Ornithodoros/physiology , Tick Infestations/epidemiology , Animals , Columbidae/parasitology , Italy/epidemiology , Population DynamicsABSTRACT
BACKGROUND: The spread of carbapenems resistance is a public health concern. The main group of carbapenemases encoding the ß-lactamases activity (bla genes) is the Metallo-ß-lactamases (MBLs). METHODS: The presence of carbapenemase blaOXA-23-like, blaOXA-40-like, blaOXA-51-like, blaOXA-58-like, and blaNDM-1 genes was screened by real time PCR in 26 Pediculus humanus insects identified from second-hand clothes in a local market in Central Italy. Bacteria diversity was also characterized through shotgun metagenomic amplification for a deep sequencing of the host-associated bacterial microbiomes. RESULTS: The blaOXA-23 and blaNDM-1 carbapenemases genes were found and metagenomic analysis showed a great presence of Acinetobacter species. CONCLUSIONS: These results suggest a new potential transmission path for carbapenemase gene spread through bacteria ingested by insects infesting humans.